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TYPE Opinion
PUBLISHED 05 December 2022
DOI 10.3389/fspor.2022.970152
Chris J. Bishop,
Middlesex University, United Kingdom
Mo Gimpel,
Red Bull Soccer, Austria
Lasse Ishøi,
Copenhagen University
Hospital, Denmark
Mark Armitage
This article was submitted to
Injury Prevention and Rehabilitation,
a section of the journal
Frontiers in Sports and Active Living
RECEIVED 15 June 2022
ACCEPTED 24 October 2022
PUBLISHED 05 December 2022
Armitage M, McErlain-Naylor SA,
Devereux G, Beato M and
Buckthorpe M (2022) On-field
rehabilitation in football: Current
knowledge, applications and future
Front. Sports Act. Living 4:970152.
doi: 10.3389/fspor.2022.970152
©2022 Armitage, McErlain-Naylor,
Devereux, Beato and Buckthorpe. This
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On-field rehabilitation in
football: Current knowledge,
applications and future
Mark Armitage1,2,3*, Stuart A. McErlain-Naylor1,4,
Gavin Devereux1, Marco Beato1and Matthew Buckthorpe3
1School of Health and Sports Sciences, University of Suolk, Ipswich, United Kingdom,
2Performance Services Department, Norwich City Football Club, Norwich, United Kingdom, 3Faculty
of Sport, Allied Health and Performance Science, St Mary’s University Twickenham, London,
United Kingdom, 4School of Sport, Exercise and Health Sciences, Loughborough University,
Loughborough, United Kingdom
field-based, rehab, soccer, injury, re-conditioning, prevention
Injury reduction remains a hot topic in professional football due to the economic and
competitive implications of time lost (1,2). Current strategies to reduce injury burden
involve either reducing primary injuries through prevention-based strategies or lowering
the risk of secondary injuries when they occur. It appears that primary injury reduction
strategies are largely effective (3,4), and might have supported reduced incidence
across the past two decades (5,6). Strategies concerning re-injury risk, however, are
less than optimal, particularly when concerning recurrent and/or high-grade muscle
and ligament injuries (1,5). Whilst return to play (RTP) rates for such injuries are
high in elite football, players often return with heightened risk of re-injury and may
experience lower performance levels, especially after severe injuries such as anterior
cruciate ligament (ACL) ruptures (714). Injuries are thought to occur due to a complex
web of determinants (15), with previous injury remaining one of the most reported
risk factors (16). Re-injuries (i.e., to the same location) or subsequent injuries (i.e., in
a different location) typically occur early in the RTP process, suggesting players might be
returned too quickly for sufficient tissue healing, or they are inadequately prepared for
RTP demands (6,1618). The role of previous injury as a risk factor for future injury can
be mitigated through effective rehabilitation (19). As such, improving RTP practice and
processes appears warranted to improve outcomes after certain injuries (e.g., high-grade
muscle/severe ligament injuries).
There is a lack of consensus on effective rehabilitation for such injuries, with current
evidence suggesting that players should embark on a criterion-based process through a
series of stages (20). These typically include early-, mid- and late-stage rehabilitation,
followed by a RTP continuum, involving on-field rehabilitation (OFR), return to team
training, return to competitive match-play and finally a return to performance (Figure 1)
(2126). Recently, there has been an increase in translational research published to
support football medicine departments with their late-stage rehabilitation processes,
specifically that of OFR (21,22,26,27). OFR as a service is not new with numerous
practitioners establishing unpublished frameworks before evidence-based practice and
Frontiers in Sports and Active Living 01
Armitage et al. 10.3389/fspor.2022.970152
A return to sport process involving a gradual transition from
rehabilitation to performance training along a continuum of
OFR, RTT, RTC, and RTPer. ORF, on-field rehabilitation; RTT,
return to training; RTC, return to competition; RTPer, return to
performance. Modified and re-printed with permission from
Buckthorpe et al. (21).
load monitoring technologies existed. Scientific developments
however have facilitated two separate published frameworks
for OFR, which use competency-based continua to provide
evidential structures to support long-established practices (21,
22,26). Despite improving clarity, such research is currently
restricted to expert opinion and/or case studies. Although this
is a complex topic with numerous inherent challenges, future
research should attempt validation of such frameworks.
The purpose of this article is to (i) review injury incidence
literature to assess the prevalence of re-injuries and postulate
OFR as a potential tool to mitigate future risk, (ii) consider injury
aetiology and the complexity of OFR, (iii) describe existing
OFR frameworks, and (iv) offer future directions related to the
development of OFR in professional football.
Injury outcomes, (re-) injury
epidemiology, and the importance
of on-field rehabilitation
Understanding injury occurrence, healing timeframes and
RTP rates are vital when designing, implementing, and
evaluating OFR frameworks. When injuries occur, they are
often categorised based on their severity, or the potential
for time loss. Most injuries are mild (7 days), and overall
RTP rates from all injuries are high, however those returning
from severe injuries (>28 days) such as ACL ruptures
often face long absence, elevated re-injury risk and reduced
performance levels (1,9). Overall, injuries have reduced by
3% per year over the past 18 years, with muscle injury
rates remaining unchanged (5). Although this should be
considered in the context of greater frequencies and intensities
of matches nowadays, muscle injuries remain a concern
given their susceptibility to re-injury (17,28). Indeed, injuries
involving musculature of the lower limbs remain notable
(15%) (1).
Ekstrand et al. (1) reported ACL re-injury rates at 6.6%,
which is in-keeping with others (29), but less than the 18%
reported by Della Villa et al. (9). However, it is perhaps
severity and not incidence which is of concern for ACL
injuries, with a mean absence of 205 days (1). Although, re-
injury rates were low in the study of Waldén et al. (29),
five out of the nine re-ruptures occurred during the final
phase of rehabilitation or before the first match, and all others
were within the first 3 months after the first match. The
timing of these re-injuries suggests an increased risk during
on-field activities and reinforces the importance of effective
OFR frameworks.
Injury aetiology and the complex
nature of on-field rehabilitation
All injuries are related to an overload of some type, whether
they involve trauma (i.e., contact), mechanical failure (i.e.,
non-contact) or a combination of both (i.e., indirect contact)
(30,31). They occur when the stress and/or strain on the
body tissue exceeds the maximal strength or failure strain of
that tissue (32). Injury prevention models have traditionally
been based on a reductionist view (15,33) that simplifies
multifaceted components into units, attempting to identify
relationships and sequence events (e.g., isolating the mechanism,
site, type, and treatment of injury) (34,35). In reality, injury
involves complex interactions between numerous factors, and so
seemingly comparable situations may yield different outcomes
(15). Contributing factors might include any combination
of neural inhibition, selective muscle atrophy, alterations in
fascicle length, strength deficits and/or increased susceptibility
to fatigue, amongst others (36). A holistic approach to
rehabilitation is therefore required to accommodate the complex
and individual nature of the process. OFR is considered a
vital component, due to the ecological validity offered by
manipulating various training stimuli to stimulate tissue loading
in a manner which more closely resembles that experienced
during training and competition (37).
Football matches are now played at a greater frequency and
intensity than ever before, which increases the physiological
and mechanical demands on players (5,38). This emphasises
the need for players to be appropriately re-conditioned to RTP
(18). Despite research warning that an imbalance in “load”
between rehabilitation and match-play might increase the risk
of re-injury (17), specific information is sparse (18). Whilst any
relationship between “training load” and injury is likely to be
associative and not definitively causative (39), clear aetiology
Frontiers in Sports and Active Living 02
Armitage et al. 10.3389/fspor.2022.970152
is yet to be established (40). Researchers and practitioners are
interested in exercise volume and intensity, and the external
and internal “loads” associated to these (41,42). To improve
understanding, there is need for agreement over terms and
technology used to describe and measure discrete outputs. For
now, multiple independent metrics are required during OFR
(e.g., running distance and velocity; step frequency, intensity,
and symmetry; heart rate; and rating of perceived exertion),
considering both the psycho-physiological and mechanical
aspects of load-adaptation pathways (38,40,43).
Existing return to play frameworks
and the developing role of on-field
To aid decision-making during rehabilitation, Creighton
et al. (44) developed a three-step model: Step 1—evaluation
of health status in consideration with medical factors; Step
2—evaluation of participation risk in consideration with
sport risk modifiers; and Step 3—decision modification in
consideration with decision modifiers. Step 1 is arguably
the most clinically important because it indicates the state
of healing and thus enables risk-assessment decision-making.
These decisions are also task-specific (Step 2). For example,
the risk associated with an upper limb injury for an outfield
player will differ to that posed by the same injury to a
goalkeeper. Finally, non-medical factors (Step 3), such as time in
season, external influences, and conflicts of interest, need to be
considered to provide context to decision-making (44). Whilst
this model provided a framework to inform decisions based on
the assessment of multiple risk factors, concerns were raised with
regards to limitations and implementation (45).
The model was modified accordingly to form the Strategic
Assessment of Risk and Risk Tolerance (StARRT) framework
(45). The structure remained the same, but the terminology
was updated alongside the ordering of contributing factors.
Although the StARRT framework was included in the
2016 consensus statement on RTP (46), the statement
suggested combining biopsychosocial factors with continued
application and evaluation of the framework. Where possible,
shared decision-making between the player, practitioner and
appropriate others should also take place (47). Practitioners
should use the available evidence and their own experiences,
combined with knowledge of the individual, specific scenario,
and club philosophy, to shape their RTP protocols (48). An
evidence-based approach to decision-making has recently been
enhanced for football through the development of two specific
OFR frameworks (21,22,26).
Buckthorpe et al. (21) offer a four-pillar structure for
practitioners to plan their on-field progressions: 1—movement
quality; 2—physical conditioning; 3—sport-specific skills; 4—
training load. Restoration of movement patterns should be
addressed first, before increasing metabolic and mechanical
demands and then integrating neurocognitive and perceptual
challenges to enhance specificity. Once the player has increased
confidence in the injury site, often in one-to-one environments,
they can begin re-introduction to team-based interactions
and the club’s conditioning model. The four pillars have
been additionally described as contributing to a five stage
OFR process (after ACL injury): 1—linear movement; 2—
multidirectional movement; 3—soccer-specific technical skills;
4—soccer-specific movements; and 5—practice simulation (22).
Whilst this framework was designed as an educational piece
to support practitioners in structuring their OFR processes,
currently there is little evidence of usage or effectiveness.
Taberner et al. (26) offer a similar five stage framework,
eloquently titled the control-chaos continuum: 1—high control;
2—moderate control; 3—control to chaos; 4—moderate chaos;
5—high chaos. Progressing sport-specific physical conditioning,
technical skills and movement qualities, practitioners are
encouraged to systematically manipulate volume and intensity
whilst increasing uncertainty of action. This framework has been
applied through a series of elite player case studies including a
male tibia-fibula fracture (49), female ACL reconstruction (50),
and male semimembranosus reconstruction (51). Whilst the
stages remained the same for each case, durations were altered
to reflect the specific needs of each injury.
Both frameworks position OFR as competency-based and
not just time dependent (21,22,26). However, there remains
a lack of validated competency criteria for RTP protocols (1).
Whilst both frameworks act as a reference guide for practitioners
and facilitate future research processes, they are based on
existing theory, experience, and inductive reasoning (52).
Experimental studies utilising hypothesis testing to promote
validation are now needed (53).
Jimenez-Rubio and colleagues attempt to provide some
evidence by using an expert panel to gain agreement for an on-
field readaptation programme following a hamstring injury (54),
and a rehabilitation and reconditioning programme following
an adductor longus injury (55). These authors performed a
follow-up study with those who completed the hamstring
protocol and reported that not only had the injury site fully
recovered, but following rehabilitation players could withstand
greater match and training demands, with a reduced risk of
future injury (56). Whilst this highlights the importance of
OFR and improving evidential structures, the 13-item OFR
programme (54) is quite prescriptive and could be challenged
given the individual nature of injuries and responses to
interventions. Conceptual frameworks such as the control-
chaos continuum and four-pillars of on-field rehabilitation
may offer greater flexibility. In essence, frameworks should
support and not dictate decision-making, with practitioners
and researchers empowered to continually evolve their practice
and understanding.
Regardless of which conceptual framework is used, it is
recommended that players progress systematically to develop
load tolerance of the injury site and restore sport specific
Frontiers in Sports and Active Living 03
Armitage et al. 10.3389/fspor.2022.970152
qualities (21,22,26). Whilst the control-chaos continuum
places a greater emphasis on cognitive demands as progressions
become more “chaotic”, both frameworks promote “load”
progression/management. Improved understanding of the
“load” requirements of specific drills/activities within each stage
and potential progression targets between stages, would support
the development of either framework.
Areas for future research
Although the frameworks use different terminology,
they both offer stepwise OFR progressions to practitioners.
Agreement in terminology would be useful to enhance
application, as would research into specific “load” responses to
explore which drills typically fall into which stages. Currently,
there is no substantial advice on how to specifically measure
and progress OFR (57). Whilst progressions within and
between sessions and stages in the available frameworks
appear rational, they are yet to be empirically established.
Training “load” appears to be a key determinant in effective
OFR (18,21,22,26,58), therefore the development of specific
sessional content (i.e., drill level analysis) should further support
practitioners in their decision-making (59). As OFR is not
a new concept, current practice with regards to drill/activity
selection (including input from technical coaches who should
be active drill designers) should be explored to identify
potential gaps and enhance application of future findings
(27). These drills/activities can then be investigated using
a range of monitoring techniques (e.g., heart rate, global
position systems, inertial measurement units, and rating of
perceived exertion, amongst others) to measure some of the
psycho-physiological and mechanical demands. Currently,
knowledge of causality between training “load” application and
successful RTP outcomes is lacking. Future research can use
the conceptual frameworks mentioned within this article to
generate testable hypotheses relating to the outcomes of specific
OFR drills/activities associated with the specified stages.
Summary and implications for
Injuries in football, particularly involving muscles and
ligaments of the lower limbs, remain problematic, with the risk
of secondary (re- or subsequent) injury remaining high. Whilst
these often occur within the first few months, risk can remain
elevated for years to come. Although epidemiological data are
supporting practitioners in targeting injury reduction strategies,
previous injury remains one of the largest risk factors for future
injury. This highlights the importance of effective rehabilitation
protocols when injuries occur, with OFR promoted as a
vital bridge between clinical rehabilitation and return to
performance. Two conceptual frameworks offer progressive
stages for OFR. Whilst these frameworks appear conceptually
sound, empirical evidence in this area is lacking. Researchers
should work together to find agreement and improve scientific
understanding. Drill level analysis, using a range of monitoring
techniques to reflect psycho-physiological and mechanical
demands, would offer greater insights into within and between
session progressions, in turn improving understanding and
application of current OFR protocols. Findings should be
critically appraised and applied by practitioners to facilitate
continued development of evidence-based practice.
Author contributions
MA was responsible for the concept and writing of this
paper. SM-N, GD, MBe, and MBu provided supervision and
feedback throughout. All authors contributed to the article and
approved the submitted version.
Conflict of interest
The authors declare that the research was conducted in the
absence of any commercial or financial relationships that could
be construed as a potential conflict of interest.
Publisher’s note
All claims expressed in this article are solely those of the
authors and do not necessarily represent those of their affiliated
organizations, or those of the publisher, the editors and the
reviewers. Any product that may be evaluated in this article, or
claim that may be made by its manufacturer, is not guaranteed
or endorsed by the publisher.
1. Ekstrand J, Krutsch W, Spreco A, van Zoest W, Roberts C, Meyer T, et al.
Time before return to play for the most common injuries in professional football:
a 16-year follow-up of the UEFA Elite Club Injury Study. Br J Sports Med. (2020)
54:421–6. doi: 10.1136/bjsports-2019-100666
2. López-Valenciano A, Ruiz-Pérez I, Garcia-Gómez A, Vera-Garcia FJ, Ste
Croix de Myer M, et al. Epidemiology of injuries in professional football:
a systematic review and meta-analysis. Br J Sports Med. (2020) 54:711–
18. doi: 10.1136/bjsports-2018-099577
Frontiers in Sports and Active Living 04
Armitage et al. 10.3389/fspor.2022.970152
3. Harøy J, Clarsen B, Wiger EG, Øyen MG, Serner A, Thorborg K, et al.
The Adductor Strengthening Programme prevents groin problems among male
football players: a cluster-randomised controlled trial. Br J Sports Med. (2019)
53:145–52. doi: 10.1136/bjsports-2017-098937
4. Petersen J, Thorborg K, Nielsen MB, Budtz-Jørgensen E, Hölmich P.
Preventive effect of eccentric training on acute hamstring injuries in Men’s soccer:
a cluster-randomized controlled trial. American J Sports Med. (2011) 39:2296–
303. doi: 10.1177/0363546511419277
5. Ekstrand J, Spreco A, Bengtsson H, Bahr R. Injury rates decreased in men’s
professional football: An 18-year prospective cohort study of almost 12 000 injuries
sustained during 1.8 million hours of play. Br J Sports Med. (2021)55:1084–
91 doi: 10.1136/bjsports-2020-103159
6. Pieters D, Wezenbeek E, Schuermans J, Witvrouw E. Return to play after a
hamstring strain injury: it is time to consider natural healing. Sports Med. (2021)
51:2067–77. doi: 10.1007/s40279-021-01494-x
7. Arundale AJH, Silvers-Granelli HJ, Snyder-Mackler L. Career length
and injury incidence after anterior cruciate ligament reconstruction
in major league soccer players. Orthopaedic J Sports Med. (2018)
6:2325967117750825. doi: 10.1177/2325967117750825
8. Barth KA, Lawton CD, Touhey DC, Selley RS, Li DD, Balderama ES, et al. The
negative impact of anterior cruciate ligament reconstruction in professional male
footballers. Knee. (2019) 26:142–8. doi: 10.1016/j.knee.2018.10.004
9. Della Villa F, Hägglund M, della Villa S, Ekstrand J, Waldén M. High rate of
second ACL injury following ACL reconstruction in male professional footballers:
An updated longitudinal analysis from 118 players in the UEFA Elite Club Injury
Study. Br J Sports Med. (2021) 55:1350–6. doi: 10.1136/bjsports-2020-103555
10. Grassi A, Rossi G, D’Hooghe P, Aujla R, Mosca M, Samuelsson K, et al.
Eighty-two per cent of male professional football (soccer) players return to play
at the previous level two seasons after Achilles tendon rupture treated with
surgical repair. Br J Sports Med. (2020) 54:480–6. doi: 10.1136/bjsports-2019-1
11. Grindem H, Engebretsen L, Axe M, Snyder-Mackler L, Risberg MA. Activity
and functional readiness, not age, are the critical factors for second anterior
cruciate ligament injury—the Delaware-Oslo ACL cohort study. Br J Sports Med.
(2020) 54:1099–102. doi: 10.1136/bjsports-2019-100623
12. Lai C, Ardern C, Feller J, Webster K. Eighty-three per cent of elite
athletes return to preinjury sport after anterior cruciate ligament reconstruction:
a systematic review with meta-analysis of return to sport rates, graft
rupture rates and performance outcomes. Br J Sports Med. (2018) 52:128–
38. doi: 10.1136/bjsports-2016-096836
13. Niederer D, Engeroff T, Wilke J, Vogt L, Banzer W. Return to play,
performance, and career duration after anterior cruciate ligament rupture: a case–
control study in the five biggest football nations in Europe. Scand J Med Sci Sports.
(2018) 28:2226–33. doi: 10.1111/sms.13245
14. Paterno MV, Rauh M, Schmitt LC, Ford KR, Hewett TE. Incidence of
second anterior cruciate ligament (ACL) injury 2 years after primary ACL
reconstruction and return to sport. Orthopaedic J Sports Med. (2013) 1:1562–
73. doi: 10.1177/2325967113S00002
15. Bittencourt NFN, Meeuwisse WH, Mendonça LD, Nettel-Aguirre A, Ocarino
JM, Fonseca ST, et al. Complex systems approach for sports injuries: Moving from
risk factor identification to injury pattern recognition—Narrative review and new
concept. Br J Sports Med. (2016) 50:1309–14. doi: 10.1136/bjsports-2015-095850
16. Hägglund M, Waldén M, Ekstrand J. Injury recurrence is lower at the
highest professional football level than at national and amateur levels: Does sports
medicine and sports physiotherapy deliver? Br J Sports Med. (2016) 50:751–
8. doi: 10.1136/bjsports-2015-095951
17. Bengtsson H, Ekstrand J, Waldén M, Hägglund M. Few training sessions
between return to play and first match appearance are associated with an
increased propensity for injury: a prospective cohort study of male professional
football players during 16 consecutive seasons. Br J Sports Med. (2020) 54:427–
32. doi: 10.1136/bjsports-2019-100655
18. Stares J, Dawson B, Peeling P, Drew M, Heasman J, Rogalski B, et al. How
much is enough in rehabilitation? High running workloads following lower limb
muscle injury delay return to play but protect against subsequent injury. J Sci Med
Sport. (2018) 21:1019–24. doi: 10.1016/j.jsams.2018.03.012
19. Tyler TF, Schmitt BM, Nicholas SJ, McHugh MP. Rehabilitation after
hamstring-strain injury emphasizing eccentric strengthening at long muscle
lengths: Results of long-term follow-up. J Sport Rehabil. (2017) 26:131–
40. doi: 10.1123/jsr.2015-0099
20. Draovitch P, Patel S, Marrone W, Grundstein MJ, Grant R, Virgile A, et al. The
return-to-sport clearance continuum is a novel approach toward return to sport
and performance for the professional athlete. Arthrosc Sports Med Rehabil. (2022)
4:e93–101. doi: 10.1016/j.asmr.2021.10.026
21. Buckthorpe M, Della Villa F, Della Villa S, Roi GS. On-field Rehabilitation
Part 1, 4 Pillars of high-quality on-field rehabilitation are restoring movement
quality, physical conditioning, restoring sport-specific skills, and progressively
developing chronic training load. J Orthopaedic Sports PhysTher. (2019) 49:565–9.
doi: 10.2519/jospt.2019.8954
22. Buckthorpe M, Della Villa F, Della Villa S, Roi GS. On-field Rehabilitation
Part 2: a 5-stage program for the soccer player focused on linear movements,
multidirectional movements, soccer-specific skills, soccer-specific movements,
and modified practice. J Orthopaedic Sports Phys Ther. (2019) 49:570–
5. doi: 10.2519/jospt.2019.8952
23. van Melick N, van Rijn L, Nijhuis-van der Sanden MWG, Hoogeboom TJ,
van Cingel REH. Fatigue affects quality of movement more in ACL-reconstructed
soccer players than in healthy soccer players. Knee Surg Sports Traumatol Arthrosc.
(2019) 27:549–55. doi: 10.1007/s00167-018-5149-2
24. Ardern C, Bizzini M, Bahr R. It is time for consensus on return
to play after injury: five key questions. Br J Sports Med. (2016) 50:506–
8. doi: 10.1136/bjsports-2015-095475
25. Buckthorpe M, Frizziero A, Roi GS. Update on functional recovery process
for the injured athlete: Return to sport continuum redefined. Br J Sports Med.
(2019) 53:265–7. doi: 10.1136/bjsports-2018-099341
26. Taberner M, Allen T, Cohen D. Progressing rehabilitation after injury:
consider the ‘control-chaos continuum.’ Br J Sports Med. (2019) 53:1132–
6. doi: 10.1136/bjsports-2018-100157
27. Dunlop G, Ardern C, Andersen TE, Lewin C, Dupont G, Ashworth
B, et al. Return-to-play practices following hamstring injury: a worldwide
survey of 131 premier league football Teams. Sports Med. (2020) 50:829–
40. doi: 10.1007/s40279-019-01199-2
28. van der Horst N, Backx FJG, Goedhart EA, Huisstede BMA. Return to
play after hamstring injuries in football (soccer): a worldwide Delphi procedure
regarding definition, medical criteria and decision-making. Br J Sports Med. (2017)
51:1583–91. doi: 10.1136/bjsports-2016-097206
29. Waldén M, Hägglund M, Magnusson H, Ekstrand J. ACL injuries in men’s
professional football: a 15-year prospective study on time trends and return-to-
play rates reveals only 65% of players still play at the top level 3 years after ACL
rupture. Br J Sports Med. (2016) 50:744–50. doi: 10.1136/bjsports-2015-095952
30. Della Villa F, Buckthorpe M, Grassi A, Nabiuzzi A, Tosarelli F,
Zaffagnini S, et al. Systematic video analysis of ACL injuries in professional
male football (soccer): Injury mechanisms, situational patterns and
biomechanics study on 134 consecutive cases. Br J Sports Med. (2020)
1423–32. doi: 10.1136/bjsports-2019-101247
31. Edwards W. Modeling overuse injuries in sport as a
mechanical fatigue phenomenon. Exerc Sport Sci Rev. (2018) 46:224–
31. doi: 10.1249/JES.0000000000000163
32. Benson LC, Räisänen AM, Volkova VG, Pasanen K, Emery CA.
Workload a-wear-ness: Monitoring workload in team sports with wearable
technology. A scoping review. J Orthopaed Sports Phys Ther. (2020) 50:549–
63. doi: 10.2519/jospt.2020.9753
33. Mendiguchia J, Alentorn-Geli E, Brughelli M. Hamstring strain injuries:
are we heading in the right direction? Br J Sports Med. (2012) 46:81–
5. doi: 10.1136/bjsm.2010.081695
34. Meeuwisse WH, Tyreman H, Hagel B, Emery C. A dynamic model of etiology
in sport injury: The recursive nature of risk and causation. Clin J Sport Med. (2007)
17:215–9. doi: 10.1097/JSM.0b013e3180592a48
35. Quatman CE, Quatman CC, Hewett TE. Prediction and prevention of
musculoskeletal injury: a paradigm shift in methodology. Br J Sports Med. (2009)
43:1100–7. doi: 10.1136/bjsm.2009.065482
36. Roe M, Malone S, Blake C, Collins K, Gissane C, Büttner F, et al. A six stage
operational framework for individualising injury risk management in sport. Injury
Epidemiol. (2017) 4:26. doi: 10.1186/s40621-017-0123-x
37. Taberner M, Allen T, O’keefe J, Cohen DD. Contextual considerations using
the ‘control-choas continuum’ for return to sport in elite football—Part 1: load
planning. Phys Ther Sport. (2022) 53:67–74. doi: 10.1016/j.ptsp.2021.10.015
38. Vanrenterghem J, Nedergaard NJ, Robinson MA, Drust B. Training
load monitoring in team sports: a novel framework separating physiological
and biomechanical load-adaptation pathways. Sports Med. (2017) 47:2135–
42. doi: 10.1007/s40279-017-0714-2
39. McCall A, Fanchini M, Coutts AJ. Prediction: the modern-day sport-science
and sports-medicine “Quest for the Holy Grail”. Int J Sports Physiol Perform. (2017)
12:704–6. doi: 10.1123/ijspp.2017-0137
40. Kalkhoven J, Watsford M, Coutts A, Edwards WB, Impellizzeri F. Training
load and injury: causal pathways and future directions. Sports Med. (2021)
51:1137–50. doi: 10.1007/s40279-020-01413-6
Frontiers in Sports and Active Living 05
Armitage et al. 10.3389/fspor.2022.970152
41. Drew MK, Finch CF. The relationship between training load and injury,
illness and soreness: a systematic and literature review. Sports Med. (2016) 46:861–
83. doi: 10.1007/s40279-015-0459-8
42. Impellizzeri F, Marcora S, Coutts A. Internal and external
training load: 15 years on. Int J Sports Physiol Perform. (2019)
14:270–3. doi: 10.1123/ijspp.2018-0935
43. Delaney JA, Duthie GM, Thornton HR, Pyne DB. Quantifying
the relationship between internal and external work in team sports:
development of a novel training efficiency index. Sci Med Football. (2018)
2:149–56. doi: 10.1080/24733938.2018.1432885
44. Creighton DW, Shrier I, Shultz R, Meeuwisse WH, Matheson GO. Return-
to-play in sport: a decision-based model. Clinical J Sports Med. (2010) 20:379–
85. doi: 10.1097/JSM.0b013e3181f3c0fe
45. Shrier I. Strategic Assessment of Risk and Risk Tolerance (StARRT)
framework for return-to-play decision-making. Br J Sports Med. (2015) 49:1311–
5. doi: 10.1136/bjsports-2014-094569
46. Ardern C, Glasgow P, Schneiders A, Witvrouw E, Clarsen B, Cools
A, et al. Consensus statement on return to sport from the First World
Congress in Sports Physical Therapy, Bern. Br J Sports Med. (2016) 50:853–
64. doi: 10.1136/bjsports-2016-096278
47. Dijkstra HP, Pollock N, Chakraverty R, Ardern C. Return to play in
elite sport: a shared decision-making process. Br J Sports Med. (2017) 51:419–
20. doi: 10.1136/bjsports-2016-096209
48. McCall A, Lewin C, O’Driscoll G, Witvrouw E, Ardern C. Return to play:
the challenge of balancing research and practice. Br J Sports Med. (2017) 51:702–
3. doi: 10.1136/bjsports-2016-096752
49. Taberner M, van Dyk N, Allen T, Richter C, Howarth C, Scott S, et al.
Physical preparation and return to sport of the football player with a tibia-fibula
fracture: applying the control-chaos continuum’. BMJ Open Sport Exer Med. (2019)
5:1–7. doi: 10.1136/bmjsem-2019-000639
50. Taberner M, van Dyk N, Allen T, Richter C, Drust B, Cohen D,
et al. Physical preparation and the return to performance of an elite female
soccer player following anterior cruciate ligament reconstruction: a journey
to the FIFA Women’s World Cup. J Orthopaed Sports Phys Ther. (2020)
6. doi: 10.1136/bmjsem-2020-000843
51. Taberner M, Haddad F, Dunn A, Newall A, Parker L, Betancur
E, et al. Managing the return to sport of the elite footballer following
semimembranosus reconstruction. BMJ Open Sport Exer Med. (2020)
6. doi: 10.1136/bmjsem-2020-000898
52. Jeffries AC, Marcora SM, Coutts AJ, Wallace L, McCall A, Impellizzeri
FM, et al. Development of a revised conceptual framework of physical
training for use in research and practice. Sports Med. (2021) 52:709–
24. doi: 10.1007/s40279-021-01551-5
53. Impellizzeri F, Ward P, Coutts A, Bornn L, McCall A. Training load
and injury part 2: questionable research practices hijack the truth and Mislead
Well-Intentioned Clinicians. In J Orthopaed Sports Phys Ther. (2020) 50:577–
84. doi: 10.2519/jospt.2020.9211
54. Jiménez-Rubio S, Navandar A, Rivilla-García J, Paredes-Hernández V.
Validity of an on-field readaptation program following a hamstring injury
in professional soccer. J Sport Rehabil. (2019) 28:1–7. doi: 10.1123/jsr.
55. Jiménez-Rubio S, Estévez Rodríguez JL, Navandar A. Validity of a
rehab and reconditioning program following an adductor longus injury
in professional soccer. J Sport Rehabil. (2021) 30:1224–9. doi: 10.1123/jsr.
56. Jiménez-Rubio S, Navandar A, Rivilla-García J, Paredes-Hernández V,
Gómez-Ruano MÁ. Improvements in match-related physical performance
of professional soccer players after the application of an on-field training
program for hamstring injury rehabilitation. J Sport Rehabil. (2020) 29:1145–
50. doi: 10.1123/jsr.2019-0033
57. Fanchini M, Impellizzeri F, Silbernagel K, Combi F,Benazzo F, Bizzini M, et al.
Return to competition after an Achilles tendon rupture using both on and off the
field load monitoring as guidance: a case report of a top-level soccer player. Phys
Ther Sport. (2018) 29:70–8. doi: 10.1016/j.ptsp.2017.04.008
58. Zambaldi M, Beasley I, Rushton A. Return to play criteria after hamstring
muscle injury in professional football: a Delphi consensus study. Br J Sports Med.
(2017) 51:1221–6. doi: 10.1136/bjsports-2016-097131
59. Allen T, Wilson S, Cohen DD, Taberner M. Drill design using the
‘control-chaos continuum’: Blending science and art during return to sport
following knee injury in elite football. Physical Therapy in Sport. (2021) 50:22–
35. doi: 10.1016/j.ptsp.2021.02.011
Frontiers in Sports and Active Living 06
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The concept of returning to sport for a professional athlete is still under debate for the professional athlete in today’s sports environment. It is critical for the professional athlete to be able to return to sport at a highly competitive level but also to return in a safe and timely measure. With no “gold standard” of sport testing, it is difficult to determine what the right progression or testing regimen should be. The Return to Sport Clearance Continuum does not look at one moment in time, but looks throughout the continuum of healing to determine readiness for sport. The purpose of this article is to explore the concept of RTS being part of an evolving continuum rather than the traditional notion that RTS is a single decision made at a discrete point in time. The principles of progressive but regular testing procedures including qualitative and quantitative movement are presented to help the professional athlete return to sport at their maximal performance level. Level of Evidence V, expert opinion.
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A conceptual framework has a central role in the scientific process. Its purpose is to synthesize evidence, assist in understanding phenomena, inform future research and act as a reference operational guide in practical settings. We propose an updated conceptual framework intended to facilitate the validation and interpretation of physical training measures. This revised conceptual framework was constructed through a process of qualitative analysis involving a synthesis of the literature, analysis and integration with existing frameworks (Banister and PerPot models). We identified, expanded, and integrated four constructs that are important in the conceptualization of the process and outcomes of physical training. These are: (1) formal introduction of a new measurable component ‘training effects’, a higher-order construct resulting from the combined effect of four possible responses (acute and chronic, positive and negative); (2) explanation, clarification and examples of training effect measures such as performance, physiological, subjective and other measures (cognitive, biomechanical, etc.); (3) integration of the sport performance outcome continuum (from performance improvements to overtraining); (4) extension and definition of the network of linkages (uni and bidirectional) between individual and contextual factors and other constructs. Additionally, we provided constitutive and operational definitions, and examples of theoretical and practical applications of the framework. These include validation and conceptualization of constructs (e.g., performance readiness), and understanding of higher-order constructs, such as training tolerance, when monitoring training to adapt it to individual responses and effects. This proposed conceptual framework provides an overarching model that may help understand and guide the development, validation, implementation and interpretation of measures used for athlete monitoring.
Full-text available
Return to play (RTP) criteria after hamstring strain injuries (HSIs) help clinicians in deciding whether an athlete is ready to safely resume previous sport activities. Today, functional and sport-specific training tests are the gold standard in the decision-making process. These criteria lead to an average RTP time between 11 and 25 days after a grade 1 or 2 HSI. However, the high re-injury rates indicate a possible inadequacy of the current RTP criteria. A possible explanation for this could be the neglect of biological healing time. The present review shows that studies indicating time as a possible factor within the RTP-decision are very scarce. However, studies on biological muscle healing showed immature scar tissue and incomplete muscle healing at the average moment of RTP. Twenty-five percent of the re-injuries occur in the first week after RTP and at the exact same location as the index injury. This review supports the statement that functional recovery precedes the biological healing of the muscle. Based on basic science studies on biological muscle healing, we recommend a minimum period of 4 weeks before RTP after a grade 1 or 2 HSI. In conclusion, we advise a comprehensive RTP functional test battery with respect for the natural healing process. Before deciding RTP readiness, clinicians should reflect whether or not it is biologically possible for the injured tissue to have regained enough strength to withstand the sport-specific forces. In an attempt to reduce the detrimental injury–reinjury cycle, it is time to start considering (biological healing) time.
Full-text available
Background Studies on subsequent anterior cruciate ligament (ACL) ruptures and career length in male professional football players after ACL reconstruction (ACLR) are scarce. Aim To investigate the second ACL injury rate, potential predictors of second ACL injury and the career length after ACLR. Study design Prospective cohort study. Setting Men’s professional football. Methods 118 players with index ACL injury were tracked longitudinally for subsequent ACL injury and career length over 16.9 years. Multivariable Cox regression analysis with HR was carried out to study potential predictors for subsequent ACL injury. Results Median follow-up was 4.3 (IQR 4.6) years after ACLR. The second ACL injury rate after return to training (RTT) was 17.8% (n=21), with 9.3% (n=11) to the ipsilateral and 8.5% (n=10) to the contralateral knee. Significant predictors for second ACL injury were a non-contact index ACL injury (HR 7.16, 95% CI 1.63 to 31.22) and an isolated index ACL injury (HR 2.73, 95% CI 1.06 to 7.07). In total, 11 of 26 players (42%) with a non-contact isolated index ACL injury suffered a second ACL injury. RTT time was not an independent predictor of second ACL injury, even though there was a tendency for a risk reduction with longer time to RTT. Median career length after ACLR was 4.1 (IQR 4.0) years and 60% of players were still playing at preinjury level 5 years after ACLR. Conclusions Almost one out of five top-level professional male football players sustained a second ACL injury following ACLR and return to football, with a considerably increased risk for players with a non-contact or isolated index injury.
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Background: The UEFA Elite Club Injury Study is the largest and longest running injury surveillance programme in football. Objective: To analyse the 18-season time trends in injury rates among male professional football players. Methods: 3302 players comprising 49 teams (19 countries) were followed from 2000-2001 through 2018-2019. Team medical staff recorded individual player exposure and time-loss injuries. Results: A total of 11 820 time-loss injuries were recorded during 1 784 281 hours of exposure. Injury incidence fell gradually during the 18-year study period, 3% per season for both training injuries (95% CI 1% to 4% decrease, p=0.002) and match injuries (95% CI 2% to 3% decrease, p<0.001). Ligament injury incidence decreased 5% per season during training (95% CI 3% to 7% decrease, p<0.001) and 4% per season during match play (95% CI 3% to 6% decrease, p<0.001), while the rate of muscle injuries remained constant. The incidence of reinjuries decreased by 5% per season during both training (95% CI 2% to 8% decrease, p=0.001) and matches (95% CI 3% to 7% decrease, p<0.001). Squad availability increased by 0.7% per season for training sessions (95% CI 0.5% to 0.8% increase, p<0.001) and 0.2% per season for matches (95% CI 0.1% to 0.3% increase, p=0.001). Conclusions: Over 18 years: (1) injury incidence decreased in training and matches, (2) reinjury rates decreased, and (3) player availability for training and match play increased.
Full-text available
Causal pathways between training loads and the mechanisms of tissue damage and athletic injury are poorly understood. Here, the relation between specific training load measures and metrics, and causal pathways of gradual onset and traumatic injury are examined. Currently, a wide variety of internal and external training load measures and metrics exist, with many of these being commonly utilized to evaluate injury risk. These measures and metrics can conceptually be related to athletic injury through the mechanical load-response pathway, the psycho-physiological load-response pathway, or both. However, the contributions of these pathways to injury vary. Importantly, tissue fatigue damage and trauma through the mechanical load-response pathway is poorly understood. Furthermore, considerable challenges in quantifying this pathway exist within applied settings, evidenced by a notable absence of validation between current training load measures and tissue-level mechanical loads. Within this context, the accurate quantification of mechanical loads holds considerable importance for the estimation of tissue damage and the development of more thorough understandings of injury risk. Despite internal load measures of psycho-physiological load speculatively being conceptually linked to athletic injury through training intensity and the effects of psycho-physiological fatigue, these measures are likely too far removed from injury causation to provide meaningful, reliable relationships with injury. Finally, we used a common training load metric as a case study to show how the absence of a sound conceptual rationale and spurious links to causal mechanisms can disclose the weaknesses of candidate measures as tools for altering the likelihood of injuries, aiding the future development of more refined injury risk assessment methods.
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ACL injuries are among the most severe knee injuries in elite sport, with a high injury burden and re-injury risk. Despite extensive literature on the injury and the higher incidence of injury and re-injury in female athletes, there is limited evidence on the return to sport (RTS) of elite female football players following ACL reconstruction (ACLR). RTS is best viewed on a continuum aligning the recovery and rehabilitation process with the ultimate aim-a return to performance (RTP erf). We outline the RTS and RTP erf of an elite female football player following ACLR and her journey to the FIFA Women's World Cup, including the gym-based physical preparation and the on-pitch/sports-specific reconditioning. We used the 'control-chaos continuum' as a framework for RTS, guiding a return above pre-injury training load demands while considering the qualitative nature of movement in competition. We then implemented the 'RTP erf pathway' to facilitate a return to team training, competitive match play and a RTP erf. Objective information, clinical reasoning and shared decision-making contributed to this process and helped the player to reach her goal of representing her country at the FIFA Women's World Cup.
The ‘control-chaos continnum’ is an adaptable framework developed to guide the onpitch rehabilitation process in elite football. One of the key components of the continuum is to progressively return players to their preinjury chronic running load, while incorporating the qualitative aspects of movement and cognitive stresses integral to competitive match-play. Whilst injury and player-specific considerations are key to an individualised rehabilitation approach, a host of contextual factors also play an important role in return to sport (RTS) planning. In this article, we highlight some key intrinsic and extrinsic contextual factors for the practitioner to consider in the RTS planning process to help mitigate reinjury risk upon a return to team training. While a return to chronic running load is a critical component of the framework, we also identify circumstances in elite football where a return to chronic running load is a less relevant factor in the decision-making process.
Context: The high rates of adductor injuries and reinjuries in soccer have suggested that the current rehabilitation programs may be insufficient; therefore, there is a need to create prevention and reconditioning programs to prepare athletes for the specific demands of the sport. Objective: The aim of this study is to validate a rehab and reconditioning program (RRP) for adductor injuries through a panel of experts and determine the effectiveness of this program through its application in professional soccer. Design: A 20-item RRP was developed, which was validated by a panel of experts anonymously and then applied to 12 injured male professional soccer players. Setting: Soccer pitch and indoor gym. Participants: Eight rehabilitation fitness coaches (age = 33.25 [2.49] y) and 8 academic researchers (age = 38.50 [3.74] y) with PhDs in sports science and/or physiotherapy. The RRP was applied to 12 male professional players (age = 23.75 [4.97] y; height = 180.56 [8.41] cm; mass = 76.89 [3.43] kg) of the Spanish First and Second Division (La Liga). Interventions: The experts validated an indoor and on-field reconditioning program, which was based on strengthening the injured muscle and retraining conditional capacities with the aim of reducing the risk of reinjury. Main outcome measures: Aiken V for each item of the program and number of days taken by the players to return to full team training. Results: The experts evaluated all items of the program very highly as seen from Aiken V values between 0.77 and 0.94 (range: 0.61-0.98) for all drills, and the return to training was in 13.08 (±1.42) days. Conclusion: This RRP following an injury to the adductor longus was validated by injury experts, and initial results suggested that it could permit a faster return to team training.
Establishing the level of risk, planning and adapting the return to sport (RTS) process following a complex knee injury involves drawing on a combination of relevant high-quality evidence and practitioner experience. A critical element of this process is on-pitch rehabilitation, providing an effective transition from rehabilitation to team training. The ‘control-chaos continuum’ (CCC) is an adaptable framework for on-pitch rehabilitation moving from high control to high chaos, progressively increasing running load demands and incorporating greater perceptual and neurocognitive challenges within sport-specific drills. Drills are a key element of the CCC, and are designed to ensure specificity, ecological validity and maintaining player interest. We showcase drill progression through the phases of the CCC, highlighting the use of constraints to create drills that incorporate the physical, technical, tactical and injury-specific needs of the player. We also provide recommendations to help practitioners create training session content using the CCC to help replicate the demands of team training within their own environment.