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Patellar Tendinopathy: Clinical Diagnosis, Load Management, and Advice for Challenging Case Presentations

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Synopsis The hallmark features of patellar tendinopathy are (1) pain localized to the inferior pole of the patella and (2) load related pain that increases with the demand on the knee extensors, notably in activities that store and release energy in the patellar tendon. While imaging may assist in differential diagnosis, the diagnosis of patellar tendinopathy remains clinical, as asymptomatic tendon pathology may exist in people who have pain from other anterior knee sources. A thorough examination is required to diagnose patellar tendinopathy and contributing factors. Management of patellar tendinopathy should focus on progressively developing load tolerance of the tendon, the musculoskeletal unit, and the kinetic chain as well as addressing key biomechanical and other risk factors. Rehabilitation can be slow and sometimes frustrating. This review aims to assist clinicians with key concepts related to examination, diagnosis, and management of patellar tendinopathy. Difficult clinical presentations (eg, highly irritable tendon, systemic comorbidities) as well as common pitfalls such as unrealistic rehabilitation timeframes and over-reliance on passive treatments are also discussed. J Orthop Sports Phys Ther, Epub 21 Sep 2015. doi:10.2519/jospt.2015.5987.
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journal of orthopaedic & sports physical therapy | volume 45 | number 11 | november 2015 | 887
[ CLINICAL COMMENTARY ]
1Musculoskeletal Research Centre, La Trobe University, Bundoora, Australia. 2Centre for Sport and Exercise Medicine, Queen Mary, University of London, UK. 3Australian Centre
for Research Into Injury in Sport and Its Prevention, Federation University, Ballarat, Australia. 4Department of Physical Therapies, Australian Institute of Sport, Canberra,
Australia. 5Department of Physiotherapy, Faculty of Health, University of Canberra, Canberra, Australia. Dr Cook is supported by the Australian Centre for Research Into Injury
in Sport and Its Prevention, which is one of the International Research Centres for Prevention of Injury and Protection of Athlete Health supported by the International Olympic
Committee. Dr Cook is a National Health and Medical Research Council practitioner fellow (ID 1058493). Mr Purdam and Dr Rio are adjunct researchers at the Australian Centre
for Research Into Injury in Sport and Its Prevention. The authors certify that they have no aliations with or financial involvement in any organization or entity with a direct
financial interest in the subject matter or materials discussed in the article. Address correspondence to Dr Peter Malliaras, Musculoskeletal Research Centre, La Trobe University,
249 Auburn Road, Hawthorn 3122 Australia. E-mail: peter@completesportscare.com.au ! Copyright ©2015 Journal of Orthopaedic & Sports Physical Therapy®
!SYNOPSIS: The hallmark features of patellar
tendinopathy are (1) pain localized to the inferior
pole of the patella and (2) load-related pain that
increases with the demand on the knee extensors,
notably in activities that store and release energy
in the patellar tendon. While imaging may assist
in dierential diagnosis, the diagnosis of patellar
tendinopathy remains clinical, as asymptomatic
tendon pathology may exist in people who
have pain from other anterior knee sources. A
thorough examination is required to diagnose
patellar tendinopathy and contributing factors.
Management of patellar tendinopathy should focus
on progressively developing load tolerance of the
tendon, the musculoskeletal unit, and the kinetic
chain, as well as addressing key biomechanical
and other risk factors. Rehabilitation can be slow
and sometimes frustrating. This review aims
to assist clinicians with key concepts related
to examination, diagnosis, and management
of patellar tendinopathy. Dicult clinical
presentations (eg, highly irritable tendon,
systemic comorbidities) as well as common
pitfalls, such as unrealistic rehabilitation time
frames and overreliance on passive treatments,
are also discussed. J Orthop Sports Phys
Ther 2015;45(11):887-898. Epub 21 Sep 2015.
doi:10.2519/jospt.2015.5987
!KEY WORDS: anterior knee pain, eccentric
exercises, knee, tendinitis
Patellar Tendinopathy: Clinical Diagnosis,
Load Management, and Advice
for Challenging Case Presentations
PETER MALLIARAS, BPhysio (Hons), PhD1,2 • JILL COOK, PhD1,3 • CRAIG PURDAM, MSportsPhysio3-5
EBONIE RIO, BPhysio (Hons), MSportsPhysio, PhD1,3
for jumping, landing, cutting,
and pivoting when participating
in these sports requires the
patellar tendon to repetitively
store and release energy.2 Energy
storage and release (similar to
a spring) from the long tendons of the
lower limb are key features for high
performance while reducing the energy
cost of human movements.2,76 Repetition
of this spring-like activity over a single
exercise session,51 or with insucient rest
to enable remodeling between sessions,81
can induce pathology and a change in the
tendon’s mechanical properties, which is
a risk factor for developing symptoms.17,6 1
Energy-storage load is defined in this
article as high tendon load, because it is
associated with tendon injury.
Although the relationship between
pain and tendon pathology is unclear,
the presence of pathology appears to be
a risk factor for an individual becoming
symptomatic.17,61 Thus, it is important
for clinicians to have an appreciation
of tendon pathology. Briefly, tendon
pathology includes increases in tenocyte
numbers and rounding, and in ground
substance expression, causing swelling,
matrix degradation, and neovascular
ingrowth.53,58 These changes have been
extensively reviewed elsewhere.1,19
Anterior knee pain in athletes can be caused by a number
of anatomical structures. Patellar tendinopathy, one
source of anterior knee pain, is most commonly
characterized by pain localized to the inferior pole of the
patella and load-related pain that increases with the demand on
the knee extensors, notably in activities that store and release energy
in the patellar tendon.33 Patellar tendinopathy is debilitating and
can result in prolonged absence
and potentially retirement from sports
participation. Cook et al16 found that more
than one third of athletes presenting for
treatment for patellar tendinopathy were
unable to return to sport within 6 months,
and it has been reported that 53% of
athletes with patellar tendinopathy were
forced to retire from sport.52
Patellar tendinopathy is primarily
a condition of relatively young (15-30
years old) athletes, especially men, who
participate in sports such as basketball,
volleyball, athletic jump events, tennis, and
football, which require repetitive loading
of the patellar tendon.57 The po wer needed
888 | november 2015 | volume 45 | number 11 | journal of orthopaedic & sports physical therapy
[ CLINICAL COMMENTARY ]
The purpose of this commentary
was to combine available evidence and
expert opinion to guide clinicians in key
elements of examination, diagnosis, and
management of patellar tendinopathy,
including advice for dicult presentations.
Examination of Patellar Tendinopathy
The first clinical challenge is to establish
whether the tendon is the source of the
patient’s symptoms. Patellar tendinopa-
thy, as one of many potential diagnoses
producing anterior knee pain, has spe-
cific and defining hallmark clinical fea-
tures32,55 that consist of (1) pain localized
to the inferior pole of the patella11 and (2)
load-related pain that increases with the
demand on the knee extensors, notably in
activities that store and release energy in
the patellar tendon.57,77 Other signs and
symptoms, such as pain with prolonged
sitting, squatting, and stairs, may be pres-
ent but are also features of patellofemoral
pain (PFP) and potentially other patholo-
gies. Tendon pain occurs instantly with
loading and usually ceases almost imme-
diately when the load is removed.75 Pain is
rarely experienced in a resting state.75 Pain
may improve with repeated loading (the
“warm-up” phenomenon),55,75 but there is
often increased pain the day after energy-
storage activities.75 Clinically, it is noted
that dose-dependent pain is a key feature,
and assessment should demonstrate that
the pain increases as the magnitude or
rate of application of the load on the ten-
don increases.55 For example, pain should
increase when progressing from a shallow
to a deeper squat, and from a smaller to a
greater hop height.
Assessing pain irritability is a funda-
mental part of managing patellar tendi-
nopathy and consists of determining the
duration of symptom aggravation (dur-
ing loading) following energy storage
activities like a training session. Studies
have suggested that up to 24 hours of
pain provocation after energy-storage
activities may be acceptable during re-
habilitation,54,83 so here we will define
“irritable” tendon pain as pain provoca-
tion of greater than 24 hours, and “stable”
tendon pain as settling within 24 hours
after energy-storage activities. Usually,
the aggravation of symptoms manifests
as pain during loading activities, such as
walking down stairs or when performing
a decline squat. Pain level can be rated on
an 11-point numeric rating scale, where 0
is no pain and 10 is the worst pain imag-
inable. The Victorian Institute of Sport
Assessment-patella (VISA-P) question-
naire is a validated pain and function
outcome measure that can also be used
to assess severity of symptoms as well as
to monitor outcomes.91 The VISA-P is a
100-point scale, with higher scores repre-
senting better function and less pain. The
minimum clinically important dierence
is a change of 13 points.47 In the authors’
experience, as progress with patellar
tendinopathy is slow and the VISA-P is
not sensitive to very small changes in the
condition, the VISA-P should be used at
intervals of 4 weeks or more.
A thorough examination of the entire
lower extremity is necessary to identify
relevant deficits at the hip, knee, and
ankle/foot region. Atrophy or reduced
strength in antigravity muscles, includ-
ing the gluteus maximus,55 quadriceps,22
and calf,55 is often observed by the au-
thors, and can be objectively assessed
with clinical tests: repeated bridging or
single-leg squat, resisted knee extension,
and repeated calf raises.46,55 Foot posture/
alignment,22,24 quadriceps and hamstring
flexibility,95 as well as weight-bearing an-
kle dorsiflexion range of motion4,62 have
been associated with patellar tendinopa-
thy and should also be assessed.
Deficits in energy-storage activi-
ties can be assessed clinically by ob-
serving jumping and hopping. There
is evidence that a sti-knee vertical
jump-landing strategy (reduced knee
flexion at peak vertical ground reaction
force) may be used by individuals with
a past history of patellar tendinopathy.9
A sti-knee strategy and then going
into hip extension rather than flexion
during a horizontal jump landing have
also been observed among participants
with asymptomatic patellar tendon
pathology.29 A systematic review ex-
amining landing strategies in 3 groups
(controls, those with asymptomatic pa-
thology, and those with symptomatic
patellar tendinopathy) reported no dif-
ferences between the controls and those
with symptomatic patellar tendinopa-
thy.89 However, the data from the meta-
analysis only included 6 symptomatic
athletes. The clinical experience of the
present authors suggests that athletes
with patellar tendon pain tend to reduce
the amount of knee flexion and appear
sti in their landing. Regardless of the
individual strategy, it is optimal to try to
distribute load through the entire kinet-
ic chain, and the purpose of evaluating
function (including hopping and land-
ing) is to identify deficits that need to be
addressed as part of rehabilitation.
Patellar tendon imaging does not
confirm patellar tendon pain, as pathol-
ogy observed via ultrasound imaging
may be present in asymptomatic indi-
viduals.61 Accordingly, serial imaging is
not recommended, as symptoms often
improve without corresponding changes
in pathology on ultrasound imaging or
magnetic resonance imaging (MRI).27,60
However, imaging can be helpful to in-
clude or exclude potential alternate di-
agnoses of anterior knee pain when the
clinical picture is unclear.14
Dierential Diagnosis
Aside from the inferior pole of the patella,
tendinopathy of the extensor mechanism
of the knee can occur at the quadriceps
tendon or distal insertion of the patellar
tendon at the tibial tuberosity. These less
common clinical presentations also have
unique features. Quadriceps tendinopa-
thy is characterized by pain localized to
the quadriceps tendon32 and, in the au-
thors’ experience, is often associated with
movements requiring deep knee flexion,
such as those performed by volleyballers
and weight lifters.72 Distal patellar ten-
don pain, often seen in distance runners,
is localized near the tibial tuberosity.32,78
The infrapatellar bursa is an intimate
part of the distal patellar tendon at-
journal of orthopaedic & sports physical therapy | volume 45 | number 11 | november 2015 | 889
tachment,8 and irritation of the bursa
often coexists with distal patellar tendi-
nopathy. Mid- or whole-tendon patellar
tendinopathy is generally the result of a
direct blow42; however, careful dieren-
tial diagnosis is required, as other struc-
tures, such as the bursae, fat pad, and
patellofemoral joint, can also be injured
with this mechanism. Although these less
common clinical presentations have dif-
ferent features and management subtle-
ties, the progressive-loading principles
described below equally apply (though
the exercises may require modification).
Pain is typically more variable in na-
ture and location when structures close
to the patellar tendon, as opposed to the
tendon itself, are the source of pain. The
contribution of Hoa’s fat pad to ante-
rior knee pain is poorly understood. But
the fat pad is known to be active in cyto-
kine production,87 to have vascular con-
nections to the patellar tendon,67 and to
have fascial connections with the patel-
lofemoral and tibiofemoral ligaments and
patellar tendon.15 Fat-pad injury may be
associated with a tibiofemoral hyperex-
tension incident,26 but insidious onset of
fat pad–related pain is also common, of-
ten associated with repetitive end-range
knee extension,26 as commonly per-
formed in some populations (eg, young
gymnasts). Infrapatellar fat-pad hyper-
trophy has been described in association
with patellar tendinopathy.23 The main
dierentiator from patellar tendinopa-
thy is the site of pain: fat-pad pain is not
localized to the inferior pole but is a more
diuse pain located in the anterior infe-
rior knee region. The pain is especially
felt during end-range extension or with
digital pressure applied directly to the fat
pad (Hoa test).26,64
The patellofemoral joint may also be
the cause of anterior knee pain among
jumping athletes. Patellofemoral-related
pain is generally located diusely around
the patella on pain mapping,68 compared
with the typically localized inferior pole
of the patella in patellar tendinopathy.
Patellofemoral pain has been suggested
to be primarily a diagnosis of exclusion,
as there are no clear sensitive and specific
clinical tests to help in the diagnosis.66,96
Athletes with PFP often report aggra-
vation of symptoms with activities that
create low tendon load, such as walking,
running, or cycling,13 which should result
in a high index of suspicion for a diagnosis
other than patellar tendinopathy. Reduc-
tion of pain, when using patellofemoral
taping, with provocative maneuvers, such
as performing a lunge or a squat, may as-
sist in confirmation of PFP.66 Patellofem-
oral joint mobility examination may also
be helpful in the dierential diagnosis.
In our clinical experience, patellar tendi-
nopathy and PFP rarely coexist, and the
clinical assessment (not tendon imaging)
should guide management.
Plica injuries79 and chondral surface
pathology may also produce anterior
knee pain. Palpation of the plica, a his-
tory of snapping sensation, and MRI
often assist in the diagnosis of a plica as
being the source of pain. Pathology of
the superior plica may be confused with
quadriceps tendinopathy both clinically
and radiologically. Clinically, plica may
be painful with activities requiring only
shallow knee flexion (eg, walking), where-
as pain from quadriceps tendinopathy is
provoked with activities requiring deep
knee flexion. On MRI, whereas quadri-
ceps tendinopathy may appear as diuse
thickening and increased signal of the
distal quadriceps tendon at its inser-
tion,86 a clearly delineated lesion deep to
the quadriceps tendon raises a high index
of suspicion for the superior plica involve-
ment.43,79 The clinical presentation of
localized osteochondral lesions of the in-
ferior region of the patella or of the troch-
lea may sometimes closely mimic patellar
tendinopathy. Clinically, joint eusion is
generally an indicator of intra-articular
injury and does not occur with either pa-
tellar or quadriceps tendinopathy.
The age of the patient must also be
considered in the dierential diagnosis
process. Both patellar tendinopathy and
isolated fat-pad irritation are common
in adolescents.13 Adding to the challenge
of diagnosis in this age group, excessive
stresses applied to developing growth
plates may result in Osgood-Schlatter
syndrome at the tibial tuberosity (com-
mon) or Sinding-Larsen-Johansson syn-
drome at the inferior pole of the patella
(rare),44 both potential causes of anterior
knee pain. People of any age are also vul-
nerable to systemic and sinister causes
of knee pain and other symptoms (eg,
tumor, infection), and these instances
of nonmechanical pain presentations
should be referred appropriately.13
Management of Patellar Tendinopathy
The most investigated intervention
for patellar tendinopathy is exercise,
especially eccentric exercise.60 For
example, the decline squat program
involves performing 3 sets of 15 repetitions,
twice daily, of single-leg eccentric squats,
with an upright torso, while standing
on a decline board (FIGURE 1).50,71,97 The
concentric phase of the squat is performed
either using both lower extremities or the
unaected side only. This program was
developed to concentrate load on the
patellar tendon.71,98 However, eccentric
FIGURE 1. Single-leg decline squat performed with
an upright torso, to 90° of knee flexion or maximum
angle allowed by pain.
890 | november 2015 | volume 45 | number 11 | journal of orthopaedic & sports physical therapy
[ CLINICAL COMMENTARY ]
exercise for the treatment of patellar
tendinopathy may be too aggressive for
patients with a high level of irritability,
particularly during the sports season.34,93
Eccentric exercise, if used in isolation, as
is often described in the literature, also
fails to address specific impairments that
may exist throughout the kinetic chain,
such as calf weakness.
Despite the widespread clinical use
of eccentric exercise for the treatment of
patellar tendinopathy,35,92 there are lim-
ited high-quality data that demonstrate
positive clinical outcomes of this ap-
proach.60 Kongsgaard et al54 performed
a randomized clinical trial comparing
heavy slow resistance (HSR) exercise
and the decline squat program. The
HSR program consisted of concentric/
eccentric squats, hack squats, and leg
presses, using both lower extremities. For
each exercise, 3 to 4 sets were performed,
progressing from an initial load based on
15 repetition maximum (15RM) to 6RM.
Pain and functional outcomes on the
VISA-P were similar at 6 months, but
patient satisfaction of those using the
HSR program was significantly greater
(70%) than patient satisfaction of those
using the decline squat program (22%).
The authors of a recent systematic
review determined that there was
limited evidence supporting the decline
squat program and moderate evidence
supporting the HSR program.60 Based
on the current evidence and their own
clinical experience, the authors of this
commentary favor the use of an HSR-
style program over the decline squat
program for the management of patellar
tendinopathy.
A 4-stage rehabilitation progression
for patellar tendinopathy is proposed,
based on the available evidence and
the authors’ opinion. The focus is on
developing load tolerance of the tendon
itself, the musculoskeletal unit, and
the kinetic chain. Key rehabilitation
exercises in each stage are outlined
(FIGURE 2). Progression criteria are
individualized, based on pain, strength,
and function (TABLE).
First, loading modification is used
with the goal of reducing pain. This
involves initially reducing high-load
energy-storage activities that may be
aggravating the pain. Volume and fre-
quency (number of days per week they
are performed) of the highest-intensity
activities, such as maximal jumping, may
need to be reduced in consultation with
both the athlete and coach. Both load
modification and eventual progressive
loading are based on careful pain moni-
toring. Some pain is acceptable during
and after exercise, but symptoms should
resolve reasonably quickly after exercise
and should not progressively worsen
over the course of the loading program,
as monitored by the 24-hour response.54
The authors measure pain response
using a pain-provocation test, such as
Stage 4: Progressive Return to Sport
• Sport-specific training (gradual training resumption)
Stage 3: Energy-Storage Exercises
• Jumping (eg, 2-leg jumps, hops, forward hops, split jumps
• Acceleration (eg, sprinting from standing start over relevant distances)
• Deceleration (eg, running and stopping suddenly on 2 limbs and then 1 limb)
Cutting (eg, running and cutting 70°)
AB
Stage 1: Isometric Exercises
ABC
Stage 2: Isotonic Exercises
FIGURE 2. Progression of patellar tendinopathy rehabilitation. Stage 1: (A) isometric knee extension performed
between 30° and 60° of knee flexion, (B) Spanish squat at 70° to 90° of knee flexion. Stage 2: (A) isotonic knee
extension, (B) leg press, (C) split squat. All exercises performed between 10° and 60° of knee flexion, progressing
to 90° as pain permits. Maintain the tibia perpendicular to the ground in the split squat, with the knee not going
forward beyond the foot, so knee flexion is less than 90°, as indicated by the blue vertical line.
journal of orthopaedic & sports physical therapy | volume 45 | number 11 | november 2015 | 891
the single-leg decline squat70 (FIGURE 1),
which is performed with an upright torso
to 90° of knee flexion or maximum angle
allowed by pain, as rated on a numeric
rating scale at maximum knee flexion an-
gle. The test is administered daily, at the
same time of day, throughout the entire
rehabilitation process. As tendon pain is
intimately linked with load, the authors
describe the response to the test as “load
tolerance.If the pain score on the load
test (eg, 1 repetition of the single-leg de-
cline squat test at the same depth) has
returned to baseline within 24 hours of
the activity or rehabilitation session, the
load has been tolerated. If the pain is
worse, load tolerance has been exceeded.
It is the authors’ opinion that pain assess-
ment based on a standard load test for
each individual is more important than
a pain rating during exercise to deter-
mine the progression of loading through
the course of the rehabilitation. Some
authors have suggested that a pain level
of up to 3 to 5 on a 0-to-10 numeric rat-
ing scale (0 is no pain and 10 is the worst
pain imaginable) during exercise is ac-
ceptable.54,83 A pain rating of 3/10 or less
is defined as acceptable and “minimal”
pain in this article, but this should only
be used as a guide, and it is reiterated that
in our opinion, greater emphasis should
be placed on the 24-hour pain response
to a predefined load test.
Stage 1: Isometric Loading Five repeti-
tions of 45-second isometric mid-range
quadriceps exercise at 70% of maximal
voluntary contraction have been shown
to reduce patellar tendon pain for 45
minutes after exercise, a response asso-
ciated with a reduction in motor cortex
inhibition of the quadriceps, which is
associated with patellar tendinopathy.74
Isometric exercises are indicated to re-
duce and manage tendon pain and ini-
tiate loading of the muscle-tendon unit
when pain limits the ability to perform
isotonic exercises.18 Isometrics, using a
knee extension machine (FIGURE 2), are
ideal for patellar tendinopathy, as they
isolate the quadriceps. In our experi-
ence, performing the isometric exercises
in mid-range knee flexion (around 30°-
60° of flexion) is more comfortable, as
people with patellar tendinopathy often
have pain when performing these with
the knee near full extension (possibly due
to impingement of the fat pad) or with
greater knee flexion. Resistance should
be increased as quickly as tolerated and
the exercise should be performed on a
single leg if possible. An alternative is
the Spanish squat6 (FIGURE 2), which is a
double-leg squat performed at an angle
of approximately 70° to 90° of knee flex-
ion (a deeper angle is generally tolerated
for a double-leg exercise) with the assis-
tance of a rigid strap fixating the lower
legs. This option can be useful, especially
when there is limited or no access to gym
equipment (eg, the traveling athlete).
The exercise dosage depends on in-
dividual factors, but evidence and clini-
cal experience indicate 5 repetitions of a
45-second hold, 2 to 3 times per day,18,74
with 2 minutes of rest between holds to
allow recovery. A 70% maximal volun-
tary contraction load, which has been
associated with reduced pain,74 can be
estimated clinically on a knee-extension
machine by selecting the resistance that
can be held for 45 seconds. The key is
to progress the load based on tolerance
and, as discussed earlier, regular reas-
sessment of pain response with load
tests. The authors have found that too
little resistance (eg, isometric knee ex-
tension as when performing quad sets
or the use of an elastic band to provide
an isometric resistance and holding at a
set deformation of the band) or progress-
ing the load too quickly and beyond load
tolerance are not eective. A good prog-
nostic sign for isometrics is an immedi-
ate reduction in pain with loading tests
(eg, a single-leg decline squat test) after
isometric exercise. It is important that
there be no muscle fasciculation dur-
ing the isometric exercises, as this may
be perceived to indicate that the load is
too high. In stage 1, isometric exercises
should be used in isolation (ie, without
isotonic loading). This stage may last
a few weeks (sometimes longer) when
managing individuals with a high level of
pain irritability. Other exercises, such as
heel raises, to address other strength or
flexibility deficits throughout the lower
extremity can also be initiated during
this initial phase.
TABLE Rehabilitation Stages
and Progression Criteria
Abbreviation: RM, repetition maximum.
*Minimal pain defined as 3/10 or less.
For example, around 150% body weight (4 × 8) for most jumping athletes.
Stage Indication to Initiate Dosage
1. Isometric loading More than minimal pain during isotonic
exercise*
5 repetitions of 45 seconds, 2 to 3 times
per day; progress to 70% maximal
voluntary contraction as pain allows
2. Isotonic loading Minimal pain during isotonic exercise* 3 to 4 sets at a load of 15RM, progressing
to a load of 6RM, every second day;
fatiguing load
3. Energy-storage loading A. Adequ ate stren gth and consistent
with other side
B. Load tol erance with initial-level energy-
storage exercise (ie, minimal pain
during exercise and pain on load tests
returnin g to baseline within 24 h)*
Progressively develop volume and then
intensity of relevant energy-storage
exerci se to r eplica te dem ands of spor t
4. Return to sport Load tolerance to energy-storage exercise
progression that replicates demands
of trai ning
Progressively add training drills, then
competition, when tolerant to full
training
892 | november 2015 | volume 45 | number 11 | journal of orthopaedic & sports physical therapy
[ CLINICAL COMMENTARY ]
The patient response to heavy isomet-
ric exercises during this stage may fur-
ther assist with confirming the diagnosis.
While people with patellar tendinopathy
report decreased pain both during and
immediately following knee extension
isometric holds, individuals with other
sources of anterior knee pain (eg, patello-
femoral joint) may feel worse using heavy
knee extension exercises (or the Spanish
squat), potentially due to high patello-
femoral joint reaction forces.85
Stage 2: Isotonic Loading Loaded iso-
tonic exercise is initiated when it can be
performed with minimal pain (3/10 or
on a numeric pain-rating scale). A posi-
tive response to regular reassessment of
pain with load tests continues to be im-
portant. Isotonic load is important to re-
store muscle bulk and strength through
functional ranges of movement. Based
on clinical experience, the HSR program
discussed earlier can be adapted to suit
the individual and maximize patient out-
comes. Initially, knee flexion during both
non–weight-bearing and weight-bearing
exercises should be limited to between
10° and 60° of knee flexion or less, de-
pending on pain, then progressed toward
90° of flexion or further, as pain permits
and based on the sport demands. The
authors have found that flexion beyond
90° and full knee extension can be pro-
vocative in the early stage of performing
isotonic exercises; that is why due caution
is warranted initially.
Exercises from the HSR program in-
clude leg presses, squats, and hack squats.
However, a common pitfall is including
only double-leg, multijoint exercises (eg,
double-leg squats) that may not address
quadriceps strength asymmetry if the
athlete spares (protects) the aected side.
The authors prefer exercises that can be
progressed easily to single-leg loading, in-
cluding leg press, split squat, and seated
knee extension (leg extension machine)
(FIGURE 2). Leg press and seated knee ex-
tension can be commenced initially and
split squats added when technique and
capacity under load are adequate. As in
stage 1, the seated knee extension ma-
chine is useful to isolate the action of the
quadriceps. The same HSR program dos-
age as used by Kongsgaard et al54 in their
clinical trial is recommended: 3 to 4 sets
at a resistance corresponding to 15RM,
progressing to 6RM, performed every
second day. It is important to progress
to heavier loading (ie, 6RM) as tolerated,
as heavy load is associated with tendon
adaptation.12
Stage 1 exercises should be continued
on the “o” days to manage pain within
the limits of muscle fatigue and soreness
associated with the isotonic loading. Stage
2 exercises should be continued through-
out rehabilitation and return to sport.
Stage 3: Energy-Storage Loading Re-
introduction of energy-storage loads on
the myotendinous unit is critical to in-
crease load tolerance of the tendon and
improve power as a progression to return
to sport. Initiating this stage is based on
the following strength and pain criteria:
(1) good strength (eg, ability to perform
4 sets of 8 repetitions of single-leg press
with around 150% body weight for most
jumping athletes); and (2) good load tol-
erance with initial energy-storage exer-
cises, defined as minimal pain (3/10 or
less on a numeric pain-rating scale) while
performing the exercises, and return to
baseline pain (if there was an initial in-
crease) during load tests, such as the
single-leg decline squat, within 24 hours.
As with the other stages, individual-
ization and clinical reasoning are neces-
sary. In addition, progression should be
developed within the context of the loads
the individual patient is required to at-
tenuate for their sport and performance
level. The following examples, extrapo-
lated from published data, may assist in
providing context to tendon loading and
force and rate changes with progression
to energy-storage exercise. A bilateral
leg press (which is not an energy-storage
loading exercise) performed with a resis-
tance equal to 3 times body weight (1.5
body weight for each lower extremity)
exerts a patellar tendon force equivalent
to 5.2 body weight and a loading rate es-
timated at around 2 body weight per sec-
ond.73 In comparison, during the landing
phase of a vertical jump, peak patellar
tendon forces have been estimated to be
5.17 ! 0.86 body weight, with a loading
rate of 38.06 ! 11.55 body weight per
second.49 Higher patellar tendon forces
are reported in the horizontal landing
phase of a stop land/jump sequence, with
peak patellar tendon forces of 6.6 ! 1.6
body weight and loading rates up to 93
! 23 body weight per second.28 This pro-
vides an understanding that the major
change through these activities is rate of
loading of the tendon, which should be
progressed gradually through relevant
energy-storage activities for the individ-
ual athlete.
Choice of exercise will depend on the
demands of the individual sport. Thus,
the selection and parameters of ener-
gy-storage programs may vary greatly
among individuals who participate in
dierent sports, as well as among posi-
tions in the same sport. Planning for this
stage requires close consultation with the
athlete and coach to appropriately deter-
mine the training frequency, volume, and
intensity of the energy-storage exercise,
and the type of exercise. Energy-storage
exercise options may include jumping
and landing, acceleration, deceleration,
and cutting/change-of-direction activi-
ties, depending on the demands of the
sport (FIGURE 2).
The start point of the energy-storage
rehabilitation protocol depends on load
tolerance and function during the initial
energy-storage exercises. For example, a
jumping athlete may initially be able to
tolerate performing only 3 sets of 8 to 10
low-intensity jumps and landings (eg,
jumps with limited jump height and/or
landing depth). The volume and inten-
sity (depth and speed of the low-inten-
sity jumps and the split squat jumps)
can then be progressed as tolerance
increases and depending on individual
goals. Eventually, higher-intensity loads/
exercises can be added in an attempt to
simulate sport-specific training volume
and intensity (eg, single-leg hops, for-
ward hops, deeper split squat jumps,
journal of orthopaedic & sports physical therapy | volume 45 | number 11 | november 2015 | 893
and sport-specific jumps such as volley-
ball block and spike jumps). This process
can take several weeks to months for
some athletes (eg, for volleyball players
to build up to the 300 landings typically
performed in a single training session).5
For athletes who do not require signifi-
cant volumes of jumping and landing
in their sport (sprinters, rugby players),
a similar progression targeting accel-
eration, deceleration, and/or cutting/
change-of-direction maneuvers may be
emphasized (FIGURE 2). Clearly, many
athletes (basketball players, for example)
may require a combination of jumping/
landing and acceleration, deceleration,
and cutting abilities.
Accurate quantification of load is im-
portant at this stage. In jumping sports,
the number and intensity of jumps and
all other energy-storage activities should
be considered to ensure that loads are
progressively applied to meet the ulti-
mate demands of the sport. For example,
a high jumper may progress through
double- to single-limb small vertical
jumps and hops, to horizontal bounding
(eg, 4-6 times, 8-12 contacts), 2-legged
hurdle jumps up to 1 m high (eg, 3 times,
8 contacts), scissor jumps over the bar
from 5-step run-up (8-10 contacts), then
flop jump from 5-step run-up (8-10 con-
tacts), and finally to a full run-up flop
jump (8-10 contacts). In essence, the
volume (ie, number of contacts or jumps)
is progressed before the intensity ( jump
height and speed) for each exercise to
approach the optimal training intensity
and energy-storage exercise demands of
the sport.
The introduction of energy-storage
exercises is often the most provocative
stage, so loading is performed every third
day initially, based on a 72-hour collagen
response to high tendon loading, as de-
scribed by Langberg et al.56 Progressions
are guided by pain experienced in the
decline squat 24 hours after exercise, as
described earlier. Stage 1 isometric loads
can be used in combination to manage
stable pain following energy-storage ex-
ercise; however, increased pain in the
load response test the day after a stage 3
training session indicates that load toler-
ance has been exceeded (irritable pain)
and loading should be adjusted accord-
ingly (eg, regress to the previous level of
training, or further, to restore load tol-
erance on load tests again). In some in-
stances, pain may increase for days after
an energy-storage progression that was
not gradual enough. Therefore, it may be
necessary to regress to solely isometrics
for several days until pain is settled. Stage
3 exercises can then be reintroduced with
modification of the progression that was
considered to be provocative. The authors
have found that performing isometric
loading (stage 1, low tendon load) and
then isotonic loading (stage 2, medium
tendon load) on subsequent days pro-
vides a 3-day, high-low-medium load
cycle (with 1 rest day per week) that is
generally well tolerated. Some athletes
feel worse the day after a rest day, requir-
ing a program that loads the tendon every
day, most likely with isometric exercises.
Stage 4: Return to Sport Progression
back to sport-specific training can be
commenced when the individual has
completed energy-storage progressions
that replicate the demands of his or
her sport in regard to the volume and
intensity of relevant energy-storage
functions. At that time, stage 3 exercises
are replaced by a graded return to training
and eventually competition. In the early
phases, training should match the volume
and intensity of final progression of stage
3 energy-storage exercises, gradually
replacing stage 3 activities with a volume
and intensity similar to those of training
drills to replicate the participation and
fitness demands of the sport. Return
to sport is recommenced when full
training is tolerated without symptom
provocation (24-hour response on load
test, such as the single-leg decline squat)
and any existing power deficits have been
resolved. The authors often use the triple
hop test for distance45 or maximal vertical
hop height for that purpose.
Ideally, sports loads (competition and
training) should be performed every 3
days, as with the stage 3 exercises, but
this can vary depending on symptom
response and demands of individual
sports/teams. Our recommendation
would be no more than 3 high-intensity
training or competition sessions that
involve energy-storage exercises within a
week in the recovering tendon, which in
elite sport is maintained as a principle for
the first year of return.
Maintenance Exercise
As a maintenance program once athletes
have returned to sport, stage 2 strength-
ening exercises are performed at least
twice per week, preferably using loaded
and single-leg exercises (eg, split squats,
seated knee extension, leg press). Stage 1
isometric exercises can be continued and
performed intermittently (eg, prior to or
after training) for their immediate eect
on pain. Athletes should also continue
addressing other relevant flexibility and
strength deficits identified throughout
the lower extremity, such as gluteal or
calf-strengthening exercises.
Common Management Pitfalls
Rehabilitation of patellar tendinopathy
can be a slow and frustrating process,
both for the athlete and clinician. There
are multiple potential management pit-
falls in the rehabilitation stages outlined,
including failure to gain control of pain,
normalize muscle capacity, eectively
progress energy-storage exercises, and
eectively progress return-to-sport train-
ing volume and intensity. More specific
pitfalls will be outlined in this section,
including unrealistic rehabilitation time
frames, inaccurate beliefs and expecta-
tions about pain, failure to identify cen-
tral sensitization, overreliance on passive
treatments, not addressing isolated
muscle deficits, failure to address kinet-
ic-chain deficits, and not adequately ad-
dressing biomechanics.
Unrealis tic Reh abilitation Time
Fram es The temptation or pressure
to shorten rehabilitation time is un-
derstandable given athletes’ eagerness
to return to sport and the demands of
894 | november 2015 | volume 45 | number 11 | journal of orthopaedic & sports physical therapy
[ CLINICAL COMMENTARY ]
competing in elite sport. In the authors’
experience, progression of rehabilita-
tion is related to symptom response to
load (load tolerance) and neuromuscular
function, both of which also determine
capacity to return to play. Progression
can be slow, sometimes taking 6 months
or longer. Bahr and Bahr5 investigated
long-term outcome after eccentric train-
ing to manage patellar tendinopathy
and determined that only 46% (6/13)
of athletes had returned to full training
and were pain free at 12 months. In the
authors’ experience, poor baseline neuro-
muscular function, muscle atrophy, pain
irritability, as well as multiple prior in-
tratendinous interventions (eg, platelet-
rich plasma or other injections) appear
to be associated with longer rehabilita-
tion times. It is important to educate pa-
tients and other stakeholders (parents,
coaches) about realistic time frames. All
stakeholders should be involved in set-
ting short- and long-term goals, based
on strength and functional targets (eg, a
leg-press strength of 8RM on the aected
side and equal performance on the triple
hop for distance are commonly used in
elite athletes by the present authors), as
these serve to motivate athletes, monitor
progress, and provide objective measures
for progression.
Inaccurate Beliefs and Expecta-
tions About Pain Beliefs about pain
and pathology may influence the
development and management of
unresponsive symptoms.7,65 Some athletes
may have been told that “tears” and
“degeneration” have caused permanent
tendon “weakening, increasing the risk
of rupture. Patellar tendon rupture (in
the absence of systemic disease) in sport
is rare.59 Some athletes may develop
fear-avoidance behavior, which has
been associated with poorer functional
outcomes in individuals with lower-limb
tendinopathy.82 Education about pain and
realistic time frames for rehabilitation
are important. This includes education
regarding the potential link between
psychosocial factors and pain. Athletes
need to be aware that pain is not
necessarily equal to harm, and some pain
during rehabilitation is acceptable. It is
important to educate patients regarding
the concept of load tolerance as defined
in this article, so that they are eventually
able to self-manage based on symptom
response to load.
Failure to Identify Central Sensiti-
zation There is evidence of sensory
and motor changes in lateral elbow
tendinopathy that suggests central
sensitization, including secondary
hyperalgesia and reduced reaction
times.10,20,31 There is a paucity of
literature on this issue, with only 1 study
demonstrating reduced mechanical pain
threshold in individuals with patellar
tendinopathy.90 Despite the lack of
supporting literature, the authors have
occasionally encountered typical central
sensitization features in patients with
patellar tendinopathy, often associated
with multiple failed injections and/
or surgery. Careful pain mapping may
identify diuse sensitivity to manual
palpation and more diuse rather than
localized pain on tendon loading. These
individuals often have a long history
of pain that is not aggravated by the
typical jumping, change-of-direction,
and other energy-storage loads that are
a clear feature of patellar tendinopathy,
suggesting that their pain is no longer
related to a tendinopathic process. Our
experience is that these patients are less
likely to respond to an isolated tendon
rehabilitation approach.
Overreliance on Passive Treat-
ments Common passive or adjunct
interventions include manual therapy,
such as transverse frictions, electrotherapy
(eg, ultrasound), shockwave therapy, and
injections (sclerosing, steroid, platelet-
rich plasma). Given that exercise is the
most evidence-based intervention,39 the
authors recommend against using only
passive interventions in the management
of patellar tendinopathy.35 While
there may be useful adjuncts for pain
management to enable rehabilitation
progression, using passive interventions
as a substitute for exercise is less than op-
timal, given that passive strategies have
not been shown to normalize tendon ma-
trix or muscle tissue or to address other
deficits throughout the lower extremity.39
The use of passive interventions may lead
to reliance on the therapist to deliver
a cure, which is misleading. Friction
massage has been shown to be less
eective than exercise as a stand-alone
intervention.84 While there is limited
evidence that shockwave may oer a
benefit equivalent to that of exercise,36,94
the exercise programs utilized in these
comparative studies were either poorly
described or not best practice. There is no
high-quality evidence (from randomized
trials) to support the stand-alone use of
other passive interventions to eectively
manage patellar tendinopathy.39
In the authors’ experience, multiple
tendon injections can lead to poorer
long-term outcomes, perhaps secondary
to protracted unloading of the tendon
and lower extremity. Kongsgaard et
al54 reported that steroid injection
used in isolation was associated with a
poorer outcome at 6 months compared
with exercise. It must be emphasized
that there are few high-quality studies
on injection therapies to date,88 and
injections are often offered when
rehabilitation has been inadequate.80 The
key strategy for avoiding multiple passive
interventions is setting realistic goals
based on a sound understanding of the
condition and its rehabilitation. Despite
potential pitfalls and limited evidence,
judicious use of passive interventions
may still be occasionally indicated, but
only as an adjunct to exercise, especially
in dicult presentations that will be
discussed below.
Not Addressing Isolated Muscle Defi-
cits Rio et al74 found that patellar
tendinopathy was associated with
substantial motor cortex inhibition
of the quadriceps, which may explain
persistent muscle atrophy with long-
standing patellar tendinopathy. Altered
neuromuscular output is likely to be
a response to pain, but may persist
even after symptoms have resolved.48
journal of orthopaedic & sports physical therapy | volume 45 | number 11 | november 2015 | 895
even in the young, active population.63
Although uncommon, symptomatic
patellar tendinopathy may be associated
with metabolic, autoimmune, or
connective tissue disease (eg, diabetes,
psoriatic arthritis).1 Symptoms are often
bilateral, and a high level of irritability
may be present. Clinicians should per-
form adequate screening to rule out
systemic comorbidities as contributing
factors to patellar tendinopathy, par-
ticularly when it is dicult to attribute
significant load history to the onset of
pain. The principles of management
for tendinopathy in the presence of a
systemic driver are as described for the
irritable tendon, but may require a refer-
ral for proper medical management.
In-season Athletes In-season athletes
with patellar tendinopathy can be dicult
to manage,18 primarily because energy-
storage loading may be dicult to modify
suciently to allow symptoms to settle. A
key requirement is to address underlying
muscle strength deficiencies within the
overall sports training environment
while persistent symptoms continue to
restrict training and competition. There
is evidence that using the decline squat
program during the season, among
jumping athletes, does not improve
symptoms,93 and may actually increase
the risk of developing pain among
athletes with asymptomatic pathology
of the tendon as seen on imaging.34
The authors have found that isometric
exercises (eg, seated knee extension,
Spanish squat holds) are most eective
at managing pain and can be performed
several times daily, as described under
stage 1 of the rehabilitation process. This
should be coupled with load management
by reducing or removing training drills
that involve high-intensity energy storage
(eg, landing or change of direction),
and intrinsic unloading through better
distribution of energy absorption
across the joints of the lower extremity
(kinetic chain). Anti-inflammatories, the
tendon polypill,30 corticosteroid (oral or
injectable),54 and high-volume injection21
may again have an adjunct role, for
Compound (bilateral and involving other
muscle groups) rehabilitation exercises,
such as double-leg squatting, lunging, and
gym-based exercise such as the leg press,
may not adequately address quadriceps
atrophy if compensatory strategies spare
the very muscle group targeted. A clinical
indicator of compensatory strategy
is fatigue in the gluteals rather than
quadriceps during compound exercises
such as the leg press. Seated knee
extension, using moderate resistance,
is an ideal exercise option because it
can specifically load the quadriceps3
and, when performed isometrically, has
demonstrated reversibility of quadriceps
inhibition immediately following the
exercise bout.74
Failure to Address Kinetic-Chain
Deficits In rehabilitation, there is a
temptation to focus on the injured site, in
this case the patellar tendon. Addressing
other potentially contributing factors
present throughout the lower extremity
is essential for successful resumption
of sporting activity. As discussed in the
assessment section, lack of hamstring
and quadriceps flexibility,95 as well as
restricted ankle dorsiflexion4,62 range
of motion and decreased calf and hip
extensor function, may be associated
with patellar tendinopathy, and
addressing these deficits should be part
of its comprehensive rehabilitation.55 A
truly comprehensive approach should
also consider deficits of the trunk
musculature as well as the contralateral
lower extremity.
Not Adequately Addressing Biomechan-
ics Athletes with patellar tendinopathy
may require progressive jump-land
retraining. The strategies of landing with
a sti knee9,29,89 and moving into hip
extension rather than hip flexion (in a
horizontal jump)29 have been associated
with higher patellar tendon injury.
Landing kinematics can be retrained,
focusing on soft landings on the forefoot-
midfoot region, with greater ankle, knee,
and hip range of motion,69 to reduce
the magnitude of peak vertical ground
reaction forces and peak loading rates.25
Landing retraining can be progressed
from double- to single-leg landings.
Importantly, changes to jump-landing
mechanics should not be attempted prior
to adequate rehabilitation (ie, meeting
criteria to progress to stage 3 energy-
storage exercise). Pain and weakness are
commonly the cause of changes in landing
strategies and should be addressed first.
Dicult Patient Presentations
This section is based on the authors’ ex-
perience and provides management guid-
ance for dicult presentations, including
athletes with highly irritable tendons,
athletes with systemic comorbidities, in-
season athletes, deconditioned athletes,
and young jumping athletes.
Highly Irritable Tendons A highly
irritable tendon is defined as the clinical
situation in which pain is significantly
and sometimes dramatically increased
for several days or weeks after even subtle
progressions of energy-storage load. The
patellar tendon that is highly irritable
may require the use of bilateral loading
exercises early in the rehabilitation
process; however, progression to single-
leg isometric loading with resistance
should remain a short-term aim, guided
by load-tolerance assessment, particularly
the 24-hour response to load. Selected
adjunct interventions, which may include
nonsteroidal anti-inflammatory drugs
or corticosteroids (taken orally or with
a peritendinous injection)18 in dicult
cases, can be very useful in reducing
symptoms to allow load progression
within a controlled rehabilitation
program. The authors have observed
that intratendinous injections, such as
platelet-rich plasma, administered to the
highly irritable tendon are more likely to
have a negative eect, potentially due in
part to the needle passing through richly
innervated peritendon.92
Systemic Comorbidities The etiology of
patellar tendinopathy is multifactorial,
including both load-related and systemic
drivers.37,38,40,41,63 Systemic pathological
drivers associated with tendinopathy
include increased central adiposity,
896 | november 2015 | volume 45 | number 11 | journal of orthopaedic & sports physical therapy
[ CLINICAL COMMENTARY ]
CONCLUSION
Patellar tendinopathy can
frequently be dicult to manage.
This review highlights key clinical
aspects in diagnosis, examination, and
management. The cornerstone of patellar
tendon management and rehabilitation
remains a highly specific and thorough
approach to progressive loading of the
lower extremity (kinetic chain), muscle-
tendon unit, and tendon itself. In this
commentary, we propose a 4-stage re-
habilitation program based on available
evidence and expert opinion that can as-
sist the clinician in guiding athletes back
to sport eectively. These stages can be
modified for dicult presentations to op-
timize management outcomes. !
example, in the short time leading up to
a tournament or toward the end of the
season. As discussed above, multiple
interventions at the expense of carefully
planned and executed rehabilitation
are not recommended, and preference
should be given to the least provocative
and least invasive options.
Deconditioned Athletes The authors
have found that athletes who return to
training and playing after a period of
inactivity are susceptible to developing
the symptoms of patellar tendinopathy,
particularly athletes with a past history
of patellar tendinopathy. This may occur
from both brief and longer periods of
inactivity due to other minor or more
severe injuries, as well as scheduled
holidays and the o-season. The primary
concern is the resulting deconditioning of
the quadriceps muscle, the muscles of the
rest of the kinetic chain, and the tendon
matrix itself, which require significant
training over time to restore. During
prolonged absences (of greater than 2
to 3 weeks, although it may be less in
some people) from training, specific
quadriceps and more general lower-
limb strengthening exercises should be
performed, along with energy-storage
exercises once or twice a week (see return-
to-sport section above), particularly for
athletes at high risk or with a history of
patellar tendinopathy.
Young Jumping Athletes The authors
have experienced particular challenges in
managing patellar tendinopathy in a sub-
set of young jumping athletes (generally
14 to 17 years of age) who develop highly
irritable symptoms. Often, symptom
onset coincides with a sharp increase in
training volume, such as starting to play
for multiple sports teams. The talented
young athlete is often highly commit-
ted, both in terms of training and play-
ing, not uncommonly across more than 1
sport and/or more than 1 team. The cor-
nerstone of management of these young
athletes includes adequate load manage-
ment and progressive rehabilitation as
described above, followed by sensible and
progressive return-to-training loads.
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[Rudavsky A, Cook J (2014) Physiotherapy management of patellar tendinopathy (jumper's knee).Journal of Physiotherapy60: xxx-xxx].
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Patellar tendon ruptures are rare but devastating injuries that frequently result from significant trauma. Males over age 40 are most commonly affected, with bilateral ruptures occurring extremely rarely. Physical examination and plain radiography are frequently sufficient to make the diagnosis, but ultrasound or MRI may be useful in assessing the quality of remaining tendon and evaluating associated intra-articular injuries. Partial tears and tendinopathy can often be successfully managed non-operatively, while complete tears require prompt surgical treatment. Both acute and chronic ruptures generally require augmentation with PDS tape or hamstring graft in order to allow for early mobilization. Some chronic tears may require reconstruction of the extensor mechanism with autograft or allograft to restore normal patellar height, particularly in patients undergoing revision surgery.
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here are common symptoms that are associated with “Jumper’s Knee”, such as pain, aching, and swelling on the lower side of the Patella on the anterior surface of the knee. Addition symptoms may include weakness and cramping of the knee joint. There are common remedies to treat "Jumper’s Knee”, such as rest, ice, compression, and elevation. Anti-inflammatory medicine, such as Aleve, Advil, or Motrin, may be appropriate in the early stages of injury. If the symptoms are left untreated, the final result may be knee surgery. A patient returning to play after diagnoses and treatment for “Jumpers Knee” should apply heat to the knee for 10 or 15 minutes before starting physical activity. Following physical activity, apply ice for 10 to 15 minutes (Donohue, 2008). Conservative treatments assist the healing process and keep Patellar Tendinopathy at bay for more than 90% of cases (Vulpiani, 2007). Along with becoming knowledgeable regarding remedies to relieve symptoms of minor “Jumper’s Knee”, it is important to know the stages of Patellar Tendinopathy. Knowledge of the warning signs and stages may assist in the avoidance of advancing the condition of Patellar Tendinopathy. Knowing the cause of Patellar Tendinopathy, the five stages, warning signs, and risk factors may assist in the process of diagnosing the injury for faster and more effective treatment. Being able to utilize the correct treatment for a particular stage of “Jumpers Knee” reduces downtime and assists the athletic trainers and doctors in the process of prescribing levels of physical activity.
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Background Few interventions reduce patellar tendinopathy (PT) pain in the short term. Eccentric exercises are painful and have limited effectiveness during the competitive season. Isometric and isotonic muscle contractions may have an immediate effect on PT pain. Methods This single-blinded, randomised cross-over study compared immediate and 45 min effects following a bout of isometric and isotonic muscle contractions. Outcome measures were PT pain during the single-leg decline squat (SLDS, 0–10), quadriceps strength on maximal voluntary isometric contraction (MVIC), and measures of corticospinal excitability and inhibition. Data were analysed using a split-plot in time-repeated measures analysis of variance (ANOVA). Results 6 volleyball players with PT participated. Condition effects were detected with greater pain relief immediately from isometric contractions: isometric contractions reduced SLDS (mean±SD) from 7.0±2.04 to 0.17±0.41, and isotonic contractions reduced SLDS (mean±SD) from 6.33±2.80 to 3.75±3.28 (p<0.001). Isometric contractions released cortical inhibition (ratio mean±SD) from 27.53%±8.30 to 54.95%±5.47, but isotonic contractions had no significant effect on inhibition (pre 30.26±3.89, post 31.92±4.67; p=0.004). Condition by time analysis showed pain reduction was sustained at 45 min postisometric but not isotonic condition (p<0.001). The mean reduction in pain scores postisometric was 6.8/10 compared with 2.6/10 postisotonic. MVIC increased significantly following the isometric condition by 18.7±7.8%, and was significantly higher than baseline (p<0.001) and isotonic condition (p<0.001), and at 45 min (p<0.001). Conclusions A single resistance training bout of isometric contractions reduced tendon pain immediately for at least 45 min postintervention and increased MVIC. The reduction in pain was paralleled by a reduction in cortical inhibition, providing insight into potential mechanisms. Isometric contractions can be completed without pain for people with PT. The clinical implications are that isometric muscle contractions may be used to reduce pain in people with PT without a reduction in muscle strength.
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Male sex, total training volume (number of hours per week) and match exposure (number of sets played per week) are risk factors for jumper's knee among young elite volleyball players. However, it is not known whether jump frequency differs among players on the same squad. To examine interindividual and sex differences in jump frequency during training and matches in young elite volleyball players. Observational study. Norwegian elite volleyball boarding school training programme. Student-athletes (26 boys and 18 girls, 16-18 years). Individual jump counts were recorded based on visual analysis of video recordings obtained from 1 week of volleyball training (9 training sessions for boys and 10 for girls, 14.1 h and 17.8 h of training, respectively) and 10 matches (5.9 h for boys (16 sets) and 7.7 h for girls (21 sets). A total of 11 943 jumps were recorded, 4138 during matches and 7805 during training. As training attendance and jump frequency varied substantially between players, the total exposure in training ranged from 50 to 666 jumps/week among boys and from 11 to 251 jumps/week among girls. On average, this corresponded to 35.7 jumps/h for boys and 13.7 jumps/h for girls (Student t test, p=0.002). Total jump exposure during matches ranged between 1 and 339 jumps among boys and between 0 and 379 jumps among girls, corresponding to an average jump frequency of 62.2 jumps/h for boys and 41.9 jumps/h for girls (Student t test, p<0.039). The interindividual differences in jump frequency were substantially greater than any differences observed among player functions. Jump frequency has substantial interindividual and sex differences during training and matches in young elite volleyball players. Total jump volume may represent a more important risk factor for jumper's knee than total training volume, warranting further research attention.
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Patellar tendinopathy (jumper's knee) is a common injury in sports that comprise jump actions. This article systematically reviews the literature examining the relation between patellar tendinopathy and take-off and landing kinematics in order to uncover risk factors and potential prevention strategies. A systematic search of the Pubmed, Embase and Amed databases was performed to identify studies that reported kinematics of sport specific jumps in relation to patellar tendinopathy. A quantitative analysis was performed on 4 indentified studies. Differences were found only between controls and asymptomatic subjects with patellar tendon abnormalities. Most differences were found during horizontal landing after forward acceleration. A synthesis of the literature suggests that horizontal landing poses the greatest threat for developing patellar tendinopathy. A stiff movement pattern with a small post-touchdown range of motion and short landing time is associated with the onset of patellar tendinopathy. Accordingly, employing a flexible landing pattern seems to be an expedient strategy for reducing the risk for (re-) developing patellar tendinopathy. Together, these findings indicate that improving kinetic chain functioning, performing eccentric exercises and changing landing patterns are potential tools for preventive and/or therapeutic purposes.