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The importance of arm action during sprint-running has been an ongoing discussion among practitioners. Though some coaches believe the arms serve to merely provide balance to the rotary momentum of the legs, others believe the arms are vital to sprint-running performance and contribute to propulsive forces. Though a large body of research has been undertaken into the effects of leg kinematics and kinetics on sprint-running performance, the role of arm action remains ambiguous and under investigated. Therefore, the purpose of this review was to improve understanding related to arm mechanics during sprint-running and provide practical context guidelines
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Role of Arm Mechanics
During Sprint Running:
A Review of the
Literature and Practical
Applications
Paul Macadam, MSE,
1
John B. Cronin, PhD,
1,2
Aaron M. Uthoff, MSc, CSCS,
1
Michael Johnston, PhD,
3,4
and Axel J. Knicker, PhD
5
1
Sports Performance Research Institute New Zealand (SPRINZ) at AUT Millennium, Auckland University of
Technology, Auckland, New Zealand;
2
School of Exercise, Biomedical and Health Sciences, Edith Cowan
University, Perth, Australia;
3
British Athletics, National Performance Institute, Loughborough University,
Loughborough, United Kingdom;
4
A-STEM, Swansea University, Swansea, United Kingdom; and
5
Institute of
Movement and Neuroscience, Research Centre for Neuromechanics and Neuroplasticity, German Sport
University, Cologne, Germany
ABSTRACT
THE IMPORTANCE OF ARM
ACTION DURING SPRINT RUN-
NING HAS BEEN AN ONGOING
DISCUSSION AMONG PRACTI-
TIONERS. ALTHOUGH SOME
COACHES BELIEVE THAT THE
ARMS SERVE TO MERELY PRO-
VIDE BALANCE TO THE ROTARY
MOMENTUM OF THE LEGS,
OTHERS BELIEVE THAT THE
ARMS ARE VITAL TO SPRINT
RUNNING PERFORMANCE AND
CONTRIBUTE TO PROPULSIVE
FORCES. ALTHOUGH A LARGE
BODY OF RESEARCH HAS BEEN
UNDERTAKEN INTO THE EF-
FECTS OF LEG KINEMATICS AND
KINETICS ON SPRINT RUNNING
PERFORMANCE, THE ROLE OF
ARM ACTION REMAINS AMBIGU-
OUS AND UNDERINVESTIGATED.
THEREFORE, THE PURPOSE OF
THIS REVIEW IS TO IMPROVE
UNDERSTANDING RELATED TO
ARM MECHANICS DURING
SPRINT RUNNING AND PROVIDE
PRACTICAL CONTEXT GUIDE-
LINES.
INTRODUCTION
Arm swing is a distinctive char-
acteristic of sprint running with
the arms working in a contralat-
eral manner with the legs to propel the
body in a horizontal direction. To
achieve high acceleration and maxi-
mum velocity, the arm-leg movements
have to be coordinated (19). To date,
a large body of research has been
undertaken into the effects of lower-
limb kinematics and kinetics on sprint
running performance (16,20,23,26,27).
A systematic literature review found
a strong relationship between lower-
limb strength and sprint running per-
formance (33); however, the role of
arm action and subsequent strengthen-
ing remains ambiguous and underin-
vestigated. Because sprint running
has distinctive phases (i.e., start,
acceleration, and maximum velocity)
and the body’s position varies through-
out these phases, it is quite likely that
the role of the arms may
change in accordance with these
phases (Figure 1). Furthermore, in team
sport events, different starting positions
are used to optimize sprint performance,
for example, a crouch start (American
football, track and field running) or
a standing start (soccer, rugby, and bas-
ketball) (36). Figure 2 highlights the dif-
ference between body and arm positions
during a block, 2-point contact, and 3-
point contact positions.
Given that evidence is limited on how
arm contribution affects track and
sport speed, understanding and refin-
ing the role of the arm during the dif-
ferent phases of sprint running would
seem important due to the potential to
improve performance outcomes. The
Address correspondence to Paul Macadam,
paul.macadam@gmail.com.
KEY WORDS:
acceleration; kinematics; kinetics;
maximum velocity; sport-specificity;
upper limbs
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purpose of this review, therefore, is
to improve understanding related to
arm mechanics during sprint running
and provide guidelines on how this
information may be used in a practical
context. Peer-reviewed journal articles
were retrieved from electronic
searches of ScienceDirect, Web of Sci-
ence, PubMed, Google Scholar, and
SPORTDiscus databases, in addition
to relevant bibliographic hand
searches with articles limited to
English language. The search strategy
included the terms arm, upper limb,
sprint, run, acceleration, and velocity.
The month of the last search per-
formed was September 2017. Articles
that discussed the role of the arms dur-
ing sprint running performance were
considered eligible for this review.
Due to the small amount of research
in sprint running in this area, articles
that assessed arm action during
running were also included in the dis-
cussion. A total of 28 studies met the
inclusion criteria for this review.
THE ROLE OF THE ARMS DURING
RUNNING AND SPRINT RUNNING
The importance of the arms during
running has been highlighted by
Egbuonu et al. (7) who reported a 4%
increase in the energetic cost of tread-
mill running without arm swing (i.e.,
arms held behind the back). Similarly,
treadmill running with the arms
crossed in front of the chest resulted
in a significant increase (8%) in the
net metabolic power demand com-
pared with running with arm swing
(2). Moreover, running without arm
swing did not change the average step
width but significantly increased step
width variability (9%) and step fre-
quency (2.5%) compared with running
with arm swing (2).
Regarding sprint running, the role and
importance of arm action during sprint
running has been an ongoing discus-
sion among researchers for several
decades. For example, Bosch and
Klomp (4) suggested that arm action
during sprint running had a greater
function than merely maintaining bal-
ance or compensating for the small dis-
turbances in body posture. The arm
action was thought to contribute to
an increase in velocity by the develop-
ment of an increased thrust in the
direction of progression (4), which
has particular importance for the start
and acceleration phase. When the
body is upright during maximum-
velocity sprint running, Bunn (6) and
Hay (10) proposed that the arms
served as a balancing action for the
hips, whereas during running, Hopper
(15) proposed that the main function of
the arm swing was to help lift the
Figure 1. Start phase (A) and maximum velocity phase (B) sprint running.
Figure 2. Block (A), 2-point contact (B), and 3-point contact (C) start positions.
Role of Arm Mechanics During Sprint Running
VOLUME 00 | NUMBER 00 | MONTH 2018
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runner off the ground. Sayers (31) sug-
gested that the arm drive had 2 main
purposes: (a) to increase both stride rate
and ground reaction forces, and, (b) to
improve balance by countering the
body’s rotation initiated by the pelvis.
Given the different point of views on
the contribution of the arms to sprint
running, the following sections discuss
the start and acceleration phase and
maximum velocity phase separately.
START AND ACCELERATION
PHASE
During the start of the sprint, the
body’s center of mass leans forward,
suggesting that the relative momentum
of the horizontal component of both
arms may not be canceled (28). Schnier
(32) and Embling (8) proposed that
a vigorous arm action would assist for-
ward drive during the start of a sprint.
It would seem that for the start and
early acceleration phases at the very
least, that understanding the impor-
tance of arm action may benefit sprint
running performance.
At the beginning of the pushing phase
during 10-m sprints from a block start,
the joint angular velocity of the rear
shoulder was linked to an extension
movement that is mainly related with
the raising of the thorax (35). It is
thought that the hands have an action
on the ground, which is associated
with the shoulder joint angular velocity
because of this extension movement
(35). After a block start, Lockie et al.
(19) reported flexion-extension joint
range of motion (ROM) for the shoul-
der (45.6–52.58and 46.4–55.08, first and
second steps, respectively) and the
elbow (53.8–66.38and 56.9–67.38, first
and second steps, respectively) in foot-
ball players, with the authors noting
small shoulder flexion (,308) may
relate to the subject’s lack of proper
sprint technique. During early sprint
acceleration, the flexion and extension
angular velocity of the humerothoracic
joint is high (approximately 7008/s)
(35), indicating that the ROM of the
scapulothoracic joint is important dur-
ing sprint running. Slawinski et al. (35)
reported that a greater variance in joint
angular velocity was found in the arms
compared with the legs, which may be
related to individual morphological
properties and starting techniques.
The importance of scapulothoracic
joint ROM is highlighted when arm
drive motion was restricted by con-
straining scapular motion with tape,
step length (24.6%) and whole body
lean position (23.9%) during the first
step was significantly decreased, subse-
quently reducing the sprinting speed
(23.2%) (28). Furthermore, Otsuka
et al. (28) found that the forward lean-
ing position of center of mass (23.9%)
Figure 3. Wearable resistance forearm loading.
Figure 4. Sled-resisted sprint running with wearable resistance.
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and the ROM of humerothoracic
extension (25.2%) were significantly
smaller than that in the free condition.
These changes in forward lean are of
interest, given that Kugler and Janshen
(18) reported higher horizontal accel-
erations were generated by more for-
ward leaning of the body at take-off,
suggesting that the forward leaning
position of the center of mass at take-
off is important for enhancing sprint
speed and undoubtedly the arms con-
tribute to this position.
Bhowmick and Bhattacharyya (3) pro-
posed that the horizontal acceleration
of the arm swing may assist in increas-
ing stride length. Moreover, the au-
thors suggested that during the start
of a sprint, the vertical component of
the arm movement may create a situa-
tion for enhanced leg drive during
ground contact, and therefore helps
to increase the forward velocity of
the main movement indirectly (3). As
previously mentioned by Lockie et al.
(19), arm-leg coordination is required
to optimize sprint running perfor-
mance. This proposal is supported by
Slawinski et al. (35) who reported that
in elite sprinters, a greater synchroni-
zation between the arm-leg increased
the efficiency of pushing on the blocks
from a sprint start. During 10-m sprint
running from a block start, it was found
that although the leg and head-trunk
segments contributed the greatest pro-
portion of kinetic energy of the total
body, the arms still contributed 22%
of the body’s kinetic energy, indicative
of the importance of these segments
during the pushing phase of the block
start (35). Slawinski et al. (34) also
investigated the initial 2 steps after
a block start and found that elite
sprinters had the ability to move their
center of mass further forward than
well-trained sprinters partially due to
the movement of their arms.
Although block starts are used in
sprint races up to 400 m, athletes will
often practice from a standing position,
whereas team sports require athletes to
sprint from an upright position (21).
Although research has investigated
acceleration performance from a stand-
ing start, no authors have examined the
contribution of the arms during this
start position and how they differ from
a block start. Salo and Bezodis (30)
found that in using a split-stance stand-
ing start, an athlete is able to increase
acceleration in the initial phase of the
sprint to a greater extent than in block
start. In a standing start, the distance
between the front and rear foot is nat-
urally long, causing the athlete to push
Figure 5. Medicine ball first step release.
Figure 6. Plate overhead step up.
Role of Arm Mechanics During Sprint Running
VOLUME 00 | NUMBER 00 | MONTH 2018
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for longer on the front foot once the
rear foot has cleared the ground (30).
Majumdar and Robergs (21) noted that
during the acceleration phase, it was
important to orient the body so that
the location of the body’s center of
mass and the center of gravity is as
forward as possible to allow for contin-
ued forward acceleration. Given the
body’s change in orientation during
the transition through the acceleration
phase, future research is required into
how changes in arm action from
a standing start can contribute to
enhancing start and acceleration phase
performance.
MAXIMUM VELOCITY PHASE
During the maximum velocity phase,
the body is upright, and the momen-
tum of the horizontal component of
the arm is not directly associated with
the body’s center of mass as the swing-
ing backward and forward motions of
the arms are in opposite directions and
the momentum is canceled (11,14).
Two-dimensional quantitative studies
by Mann (22) and Mann and Herman
(23) found that there was a minimal
amount of muscular contribution from
the shoulder and elbow joints during
the maximum velocity phase of sprint
running. Mann and Herman (23)
compared the performance of the
first- and eighth-place sprinter during
the maximum velocity phase of a 200-
m race. The faster sprinter had a greater
arm displacement from the shoulder
(1358versus 1188) and elbow (848ver-
sus 678) joints with a greater average
speed from the shoulder (5258/s versus
4908/s) (23). From the analysis of mus-
cle moments from 15 sprinters who
ranged in experience from collegiate
to world class, Mann (22) proposed
that activity from the shoulder joint
related to maintaining balance, and
activity from the elbow indicates that
its purpose is to maintain the forearm
in a flexed position; however, the opti-
mum positions are yet to be estab-
lished. Furthermore, it was suggested
that no relationship existed between
arm action and sprint running perfor-
mance (22). Consequently, the authors
suggested that the role of the arms dur-
ing sprint running was to maintain bal-
ance (22,23). However, due to the
limited number of subjects and the dif-
ference in their levels of sprint running
experience, understanding arm action
during the maximum velocity phase
clearly requires further research.
Researchers analyzing the effects
of arm swing during treadmill
running using 3-dimensional motion
analysis found that the vertical ROM
of the body center of mass was
increased 5–10% by arm swing (14).
The authors proposed that the primary
lift mechanism occurs during the mid-
contact phase whereby the upward
acceleration of the arms, relative to
the trunk, produces a greater vertical
impulse on the body as a whole (14).
The lift provided by the arms was
found to increase as running speeds
increased, therefore highlighting their
potential importance at higher sprint
running speeds. This finding may be
of significance during the start phase
as Young et al. (38) reported that when
the body has a significant forward lean,
the vertical lift provided by the arm
drive has a horizontal propulsive
component. Hinrichs et al. (13) re-
ported that the arms were involved
in reducing total-body angular
momentum about a vertical axis
through the body’s center of mass
when running in an upright position.
However, Hinrichs (12) reported that
the arms possess the potential to
compensate for each other and for
asymmetries elsewhere in the body
during treadmill running. Bunn (6)
suggested that a vigorous backswing
of the arms caused an increased leg
stride and assisted to maintain veloc-
ity when the legs fatigued. More
research into the role of the arms dur-
ing the maximum velocity phase is
required coupled with understanding
the transition through all phases of
sprint running.
Figure 7. Standing transition arm drive.
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TRAINING STRATEGIES FOR ARM
DRIVE
Although coaches believe that the arms
play a vital role in sprint running (17,37),
the training strategies to improve arm
mechanics for sprint running remain rel-
atively unexplored. Young et al. (38) pro-
posed that the muscles that drive the
arms may be relatively more important
for short sprints. However, although the
standing and seated arm swing exercises
are commonly implemented to enable an
athlete to focus on the actions of the
upper limbs (5), only a few researchers
have specifically investigated the effects
of training interventions on arm mechan-
ics for sprint running. This section dis-
cusses the findings of these articles in
relation to the start and acceleration, as
well as the maximum velocity phase.
START AND ACCELERATION
PHASE
Acute changes were examined during
40-m overground sprint running with
wearable resistance of 0.5 kg attached
to each arm using a weighted sleeve on
10 male recreationally trained athletes
from field-based sporting clubs (25).
No significant differences were found
at the start phase between loaded and
unloaded conditions in 10-m best time
(20.4%) and 10-m average time
(21%), with Cohen effect sizes trivial
(,0.2) for both changes (25). The loads
were positioned on the dorsal side of
the forearm, held to the arm by an
elastic sleeve extending from the wrist
to above the elbow, and secured with
velcro straps. Subject’s body mass
(BM) was not reported; therefore, the
magnitude of this load as a percentage
of BM was unknown. McNaughton
and Kelly (25) proposed that as no det-
rimental effects were found in perfor-
mance, the forearm loads may provide
a suitable overload stimulus during
speed training sessions without nega-
tively impacting technique or perfor-
mance. An earlier study on 24 male
physical education students used loads
of 0.2, 0.4, and 0.6 kg (0.3–0.9% BM)
lead rods, held in each hand, during 30-
m over the ground sprint running (29).
Similarly, Ropret et al. (29) reported no
changes in velocity, stride rate, or stride
length with any loaded condition over
the initial 15 m compared with the un-
loaded sprint. From these findings, it
may be concluded: (a) that arm loads
Figure 8. Double-arm pillar press.
Role of Arm Mechanics During Sprint Running
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of #0.6 kg do not seem to interrupt
spatiotemporal variables and hence
introduce technique breakdown, (b)
preference would be to affix load to
the lower area of the arms, which in-
creases the rotational inertia and en-
sures that the hands are not gripping
a load, which may increase unwanted
tension in the arm and shoulders, and,
(c) it may be that the magnitude of
loads used in the aforementioned stud-
ies may not have been sufficient to sig-
nificantly overload arm mechanics
during the initial 15 m, and future
research with heavier wearable resis-
tance is required.
When sprint running was performed
with a sled resistance, the athlete’s
body position was forced into an
increased forward lean (19,24). Conse-
quently, Lockie et al. (19) reported that
athlete’s arm drive exhibited a greater
range of shoulder joint flexion over the
initial 2 steps (;2–38) after an 8-week
sled training study. As athletes are cued
at the start of the sprint to take-off
in a more horizontal position,
sled-resisted sprint running with 20%
BM resulted in a 9% more horizontal
take-off angle from a block start (24).
Therefore, the subsequent forward lean
position achieved with sled-resisted
sprint running partly mirrors the start
phase of a sprint and may be an effec-
tive training modality for practitioners
seeking changes in early sprint arm
drive kinematics. Whether this is the
case, especially because the arms are
not directly overloaded, needs to be
investigated further.
MAXIMUM VELOCITY PHASE
During the maximum velocity phase,
sprint running with a loaded arm con-
dition of 0.5 kg per arm had no signif-
icant effect on 40-m best time (20.2%)
and 40-m average time (20.2%), with
Cohen effect sizes trivial (,0.04) for
both changes (25). Moreover, no sig-
nificant effect was found for average
velocity (20.5%, effect size 50.08)
(25). Ropret et al. (29) reported that
no acute effects were found in sprint
performance over 15–30 m until the
heavier loads (0.6 kg, 0.9% BM) were
used, which resulted in a significant 1%
decrease in velocity between the un-
loaded and handheld loaded sprint
conditions. No significant changes
were found in stride frequency or stride
length during the maximum velocity
phase, although stride length was
reduced ;3 cm with the 0.6 kg loaded
condition (29). A dearth of quantitative
research exists relating to the optimum
mechanics of the arms during sprint
running. Moreover, from qualitative
research, coaches believed that arm
mechanics differ between the maxi-
mum velocity phase and the earlier
phases of sprint running. Coaches
identified that the arms assist in stabi-
lizing the trunk, and work in tandem
with the legs to stabilize and balance
the body when an athlete is upright
and maintaining maximum speed (17).
PRACTICAL APPLICATIONS
Although coaches recognize the
importance of the arm drive in sprint
running, the role of the arms during
the different phases of the sprint, and
the training of the arms has not been
Figure 9. Single-arm pillar press.
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articulated to any great detail. This
review attempted to synthesize the avail-
able information by first enhancing the
understanding of the role of the arms
during the start and acceleration versus
the maximum velocity phases of sprint
running. By understanding these differ-
ential roles and subsequent mechanics,
programing needs to become clearer.
The following section describes a small
selection of exercises that may assist the
practitioner in the training of the arms
specific to the phase of sprinting.
START AND ACCELERATION
PHASE
Two previous sprint running studies that
used loads attached to the arms or
hands were found to not overly
alter the spatiotemporal variables.
Therefore, sprint running with wearable
resistance attached to the arms (Figure 3)
may be a suitable training stimulus with-
out unduly affecting start and accelera-
tion kinematics, which may lead to
positive performance adaptations. Wear-
able resistance attached to the forearms
may create a greater horizontal propul-
sion at take-off due to the greater
amount of rotational inertia from the dis-
tal loading of the arms.
Due to the orientation of body (i.e., more
of a horizontal lean) during the start
phase, the vertical lift provided by the
arm drive has a horizontal propulsive
component, and therefore, optimizing
arm action may enable a greater horizon-
tal propulsion. At the start of a sprint,
there is a technical emphasis for athletes
to take-off in a more horizontal position.
Moreover, research has found that the
forward leaning position of the center
of mass at take-off is important for
enhancing sprint speed. Therefore, sprint
running training with resisted sleds (Fig-
ure 4) is one modality that enables this
body position to be maintained, which
results in a greater arm drive action from
a larger shoulder joint ROM. Although
there is no direct overload of the arms in
this position, the orientation of the
body may enable a training stimulus for
greater arm velocity and limb coordina-
tion to be achieved. In addition, with
wearable resistance attached to the fore-
arms (Figure 4), an overload of the arm
action can be achieved. However, this
proposal is speculative and future
research is needed to disentangle
whether this type of training has any
effect on arm drive kinematic and kinet-
ics, and therefore, sprint performance.
Future research is required to find an
optimum magnitude of wearable resis-
tance because a load too heavy may
result in negative arm kinematics as
the athlete struggles to maintain a high
velocity arm drive. Given the impor-
tance of the arm drive during push-
off and acceleration, practitioners
should focus on arm-leg coordination
and their contralateral positions.
In addition to traditional sprint and
resistance training, a series of
Figure 10. Shoulder asymmetry assessment during standing arm drive. (A) neutral shoulders. (B) elevated left shoulder.
Role of Arm Mechanics During Sprint Running
VOLUME 00 | NUMBER 00 | MONTH 2018
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exercises used by coaches to
improve arm drive function and
arm-leg coordination during the
start and acceleration phase are
illustrated in Figures 5–7. The med-
icine ball first step release (Figure 5)
is a loaded arm exercise that may be
used to enhance arm drive extension
andpropulsionrequiredduringthe
initial first step. The plate loaded
overhead step (Figure 6) may be
used to enhance arm drive to assist
arm-leg coordination and horizontal
propulsion by overloading the shoul-
der and elbow joints in conjunction
with the lower limbs. The standing
transition arm drive (Figure 7) may
be used by coaches to improve arm
drive technique and rate-of-rise
rhythm through transitioning from
the start to maximum velocity phase
by coordinating the timing of the
arms with the change in the body’s
orientation from a leaning forward
position to an upright position. The
reader needs to be cognizant that
there may be limitations to these ex-
ercises because: (a) the upward pro-
pulsion of the ball and plate may
result in significant thoracic exten-
sion, (b) the exercises bias vertical
force production, and (c) there is
no counterbalance from (for exam-
ple) the opposite arm.
MAXIMUM VELOCITY PHASE
During the maximum velocity phase
of sprint running, the body is upright.
When sprint running in this position,
the arms contribute to the total ver-
tical propulsive forces applied to the
ground; therefore, optimizing arm
mechanics in symmetry with the legs
should be a consideration for training
planning. Athletes should train to
achieve an effective arm swing that
originates from the shoulder and
has a flexion and extension action at
the shoulder and elbow that is
matching to the flexion and exten-
sion occurring at the ipsilateral
shoulder and hip. The double-arm
pillar press exercise (Figure 8) and
the single-arm version (Figure 9)
can be used to strengthen the
shoulders and triceps. In addition, ex-
ercises similar to those illustrated in
Figures8and9maybeusedtocon-
comitantly reinforce postural integ-
rity, balance, and arm-leg
coordination.
It may be argued that the vertical
plane–only exercises, depicted in
Figures 8–9, are somewhat non-
specific, given the discussion of the
role of the upper body in maximum-
velocity running. Given such a con-
tention, the utilization of some track
drills to challenge the coordination of
the arms with the trunk and hips
should also be considered to help
identify training needs. For example,
an upright version of the arm drill
(Figure 10)—starting on flat foot and
coming up to plantar flexion—could
demonstrate/challenge asymmetry
from the hip to the shoulder to better
effect. In this example, Figure 10B
clearly demonstrates the impact that
poor function in the left shoulder can
have on the trunk (side flexion) and
the pelvis (left anterior/medial rota-
tion). This in turn may lead to a series
of antirotation trunk and shoulder
mobility exercises with the aim of
improving relative stiffness between
the shoulder and the hip.
CONCLUSIONS
The role of arm drive remains a con-
tentious topic among sprint coaches
and in the published literature.
Although the arms do seem to coun-
terbalance the rotary momentum of
the legs during sprint running, it
would seem that the arms may addi-
tionally have an important role dur-
ing the start and early acceleration
phase of the sprint. Although the
horizontal force capabilities of the
arms are very limited, owing to
the simultaneous forward-backward
action of contralateral arms when
an athlete is upright, due to the early
forward lean position, the relative
momentum of the horizontal com-
ponent of both arms may not be can-
celed. Moreover, the arms may
contribute up to 10% of the total ver-
tical propulsive forces an athlete is
capable of applying to the ground
(14), highlighting the importance of
an efficient arm action. Elite sprinters
exhibitagreaterarm-legsynchroni-
zation, increasing the efficiency of
pushing on the blocks; therefore,
optimizing arm mechanics in syn-
ergy with the legs should be a pro-
gramming consideration.
The importance of this arm-leg syn-
chronization is supported in neuro-
science research, where Frigon et al.
(9) demonstrated that rhythmic arm
movement affected reflexes in leg
muscles independent of arm position.
Moreover, arm swing frequency also
regulated not only hip-shoulder
interaction at low frequencies but
predominantly ankle-shoulder in-
phase coordination at higher fre-
quencies, suggesting a tight coupling
between arm swing and postural
coordination (1). Although not
related directly to sprint running,
the findings do suggest that more
research is needed on arm-leg coor-
dination and the effects of training
the arms alone to quantify changes
in sprint performance.
Conflicts of Interest and Source of Funding:
The authors report no conflicts of interest
and no source of funding.
Paul Macadam
is a PhD candi-
date at Auckland
University of
Technology.
John B. Cronin
is a Professor of
Strength and
Conditioning at
Auckland Uni-
versity of
Tec h no l og y and
holds an adjunct
professorial posi-
tion at Edith Cowan University.
Strength and Conditioning Journal | www.nsca-scj.com 9
Copyright ªNational Strength and Conditioning Association. Unauthorized reproduction of this article is prohibited.
Aaron M.
Uthoff is a PhD
candidate at
Auckland Uni-
versity of
Technology.
Michael
Johnston is
Lead Strength
and Conditioning
Coach for the
British Athlet-
ics team.
Axel J. Knicker
is a Senior Lec-
turer of Move-
ment and
Neuroscience at
German Sport
University
Cologne.
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Role of Arm Mechanics During Sprint Running
VOLUME 00 | NUMBER 00 | MONTH 2018
10
Copyright ªNational Strength and Conditioning Association. Unauthorized reproduction of this article is prohibited.
... During sprinting, athletes usually gain forward momentum by contacting the ground with the ball of the foot while the ankles are kept rigid [64]. After a quick forward swing, to gain stronger forward momentum, athletes commonly tend to be more proactive in completing the movement of touching the ground by pressing down quickly and swinging the leg backward [65]. The hamstring muscles are always active throughout the gait cycle; because of the need to swing and contact the ground, they quickly switch between eccentric and concentric contraction [66,67]. ...
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Hamstring injury has been considered one of the most common exercise-induced injuries in sports. Hamstring injuries mostly occur proximal to the biceps femoris. However, the reasons and mechanisms remain unclear. To summarize hamstring morphological structure features and what the relationship is between their structure and risk of injury from the current literature, this review discussed the possible injury mechanism of hamstrings, from the morphological and connected pattern diversity, the mechanical properties, and the stress–strain performance, to probable changes in action control. Morphological and connected pattern diversity of hamstrings components show heterogeneous loads under muscle tension. Connections of gradient compliance between different tissues may lead to materials’ susceptibility to detachments near the tendon–bone junction sites under heterogeneous load conditions. The hamstrings muscle’s motor function insufficiency also brings the risk of injury when it performs multi-functional movements during exercise due to the span of multiple joints’ anatomical characteristics. These structural features may be the primary reason why most damage occurs near these sites. The role of these biomechanical characteristics should be appreciated by exercise specialists to effectively prevent hamstring injuries. Future work in this research should be aimed at exploring the most effective prevention programs based on the material structure and motor control to enhance the properties of hamstring muscle materials to minimize the risk of injury.
... ± 0.57 and -0.62 ± 0.65, respectively) in the 50% of body mass condition was observed alongside no decrements in sprint performance following both conditions and all recovery durations. It is likely that the lack of significance may have been as a result of the sled pushing altering participants natural sprint mechanics through removal of the arm action, excessive forward trunk lean and an increase in ground contact times (30). Likewise, the load imposed during the 100% of body mass condition may have been too great, lacking transfer to that of maximal sprint speed and the ability of youth participants to derive benefits from heavy resistance CE (47). ...
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This investigation examined the effects of a warm-up containing weighted vest (WV) sprints on subsequent 20-metre sprint time relative to a control (C) condition in youth soccer players (n=12, mean ± SD age 16 ± 0.60 years, height 175.17 ± 5.92 cm and body mass 61.85 ± 5.88 kg). The main experimental trials consisted of three WV conditions at 10, 20 and 30% of body mass (WV10, WV20 and WV30) and C. Participants were required to complete one 20-metre sprint with each of WV conditions or without additional mass as part of C prior to a 20-metre sprint at 4-, 8- and 12-minutes. A two-way repeated measures ANOVA revealed no significant difference between any of the conditions and rest periods (p = >0.05). The between condition effect sizes for 20-metre sprint times were moderate at 4- and 12-minutes post WV10 (d = -0.86 and -1.15, respectively) and 12-minutes post WV20 (d = -0.84) and WV30 (d = -0.80). Moderate effect sizes were also observed at 4-minutes post WV10 (d = -1.04) and WV20 (d = -0.67) for 10-metre sprint times. These findings demonstrate that WV loading has no significant effect on 20-metre sprint time in youth soccer players. However, there is an opportunity for S&C coaches to implement WV warm-ups of no more than 30% body mass to improve 20-metre sprint times.
... The extent of the associations (moderate to large) between sprinting speed (over 10 and 20 m) and peak rear leg GRF for the rear hand punches is interesting given that sprinting involves both lower-and upper-body actions. While the rear leg exerts larger peak forces compared to the lead leg during a sprint start in order to propel the centre of mass forward (Harland & Steele, 1997;Majumdar & Robergs, 2011;Mero, Kuitunen, Harland, Kyrolainen, & Komi, 2006), the upper-body has been shown to contribute as much as 22% of the body's kinetic energy during a sprint start, which assists velocity through increased propulsion in the direction of movement (Macadam, Cronin, Uthoff, Johnston, & Knicker, 2018;Slawinski et al., 2010). Such overall movement speed will be a 'performance' asset owing to the limited time-frame in which a boxer has to execute offensive and defensive strategies (Chang et al., 2011;James, Kelly, & Beckman, 2014). ...
Thesis
Full-text available
Punches in boxing are intricate actions requiring the coordinated and synergistic recruitment of leg, trunk and arm musculature. Maximal punches can have a marked impact on the outcomes of boxing contests. Currently, there is an absence of research appraising the biomechanics and physical performance-related qualities associated with boxing punches, and as such, there are no practical guidelines pertaining to resistance training and its impact upon these important characteristics. In this respect, coaches and boxers are reliant consequently upon non-scientific approaches to training and contest preparation. Thus, the purpose of this thesis was to quantify the biomechanics and physical performance-related qualities associated with maximal punching techniques common to amateur boxing, and investigate the extent to which resistance training enhances such features. Study 1 quantified the three-dimensional kinetics and kinematics of maximal punches common to boxing competition to identify the differences between punch types (straights, hooks, and uppercuts), whilst Study 2 investigated the movement variability of these measures across punch types. These studies revealed significant differences for the majority of kinetic and kinematic variables between punch types. High within-subject, between-subject, and biological variability were recorded for the same variables across punch types, independent of the amount of boxing experience. These findings confirm that kinetic and kinematic characteristics vary from punch to punch, with boxers appearing to manipulate kinematic variables in order to achieve a consistent intensity and end-product. Study 3 quantified the relationships between physical performance-related traits and kinetic and kinematic qualities of maximal punches, and revealed moderate-to-large associations with muscular strength and power. From this, Study 4 appraised the extent to which strength and contrast resistance training enhanced maximal punch biomechanics and physical performance-related qualities. The findings highlighted that contrast training was superior among male amateur boxers over a six-week intervention, though strength training alone also brought about improvements. This current research has advanced our understanding of maximal punching and the influence of resistance training on a variety of its determinants. Nonetheless, future research is required to identify if the same findings can be generalised to higher standards of boxing and whether alternative strength and conditioning strategies are equally, or more effective.
... Arm restriction was also pointed out to explain speed decrease in PC condition . During running, arm movements are crucial to control and maintain posture and participate (nearly 10%) to total vertical propulsive forces (Macadam, Cronin, Uthoff, Johnston, & Knicker, 2018). A lack of arm-leg coordination related to pole carriage might reduce the forces applied in running and alter postural control strategy with higher implication of the lower limbs and trunk. ...
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In pole vaulting, take-off speed is considered as a major determinant of performance. Pole carriage could affect the speed acquired during the approach and at the take-off. This study investigated different types of runs performed randomly by young male and female expert athletes: maximal sprint, maximal pole carriage run, maximal run-up with simulated pole plant and competition situation. Speed profile was determined with a radar gun and spatiotemporal parameters were recorded for the last 20 m of the approach with the Optojump Next system. For both genders, mechanical variables were compared using two-way ANOVAs with repeated measurements. Pole carriage represents the main cause of speed decrease for both men (−5.8%) and women (−6.2%). A step rate decrease during pole carriage was pointed out with an increase of contact time for both men and women. Significant speed decrease was observed for women at the take-off compared to pole plant simulation (−4.3%), while not for men. Those results provide a new insight for pole vault training allowing to update training process with specific exercises leading to reduce speed loss at take-off.
... However, unilateral WR of the lower body has not been examined and may have noticeably different effects than the aforementioned studies as the upper limbs can be used naturally, allowing for high-velocity locomotion. 16 Furthermore, it is critical to understand the acute effects of asymmetrical WR loading before implementing it during a training or rehabilitative intervention. Therefore, we aimed to compare the kinetics and kinematics of high-speed running with unilateral lower body WR. ...
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Context: Light lower-limb wearable resistance has little effect on running biomechanics. However, asymmetrical wearable resistance may potentially alter the kinetics and kinematics of high speed, enabling greater loading or unloading of an injured or rehabilitative lower limb. Design: A cross-sectional study design was used to quantify the influence of asymmetric calf loading on the kinematics and kinetics during 90% maximum sprinting velocity. Methods: Following a familiarization session, 12 (male = 7 and female = 5) physically active volunteers ran at 90% of maximal velocity. In random order, participants ran with zero (0) wearable resistance and with loads of 300 g (L300) and 600 g (L600) fixed to one shank. A nonmotorized treadmill quantified vertical and horizontal kinetics and step kinematics. The kinetics and kinematics of the loaded (L0, L300, and L600) and unloaded (UL; UL0, UL300, and UL600) limbs were compared. Results: Vertical step ground reaction force of the loaded limb tended to increase between unloaded and 300 and 600 conditions (effect size [ES] = 0.48 to 0.76, all P ≤ .12), while the horizontal step force of the UL tended to decrease (ES = 0.54 to 1.32, all P ≤ .09) with greater external loading. Step length increased in the UL in 0 versus 300 and 600 conditions (ES = 0.60 to 0.70, all P ≤ .06). Step frequency decreased in the ULs in unloaded versus 300 and 600 conditions (ES = 0.73 to 1.10, all P ≤ .03). Mean step velocity tended to be greater in the ULs than the 300 and 600 conditions (ES = 0.52 to 1.01, all P ≤ .10). Only 4 of 16 variables were significantly different between the 300 and 600 conditions. Conclusions: Asymmetrical shank resistance could be used during high-speed running to reduce or increase the kinetic loading of an injured/rehabilitative limb during return to play protocols. Asymmetrical wearable resistance could also be used to alter step kinematics in runners with known asymmetries. Finally, meaningful alterations in high-speed running biomechanics can be achieved with only 300 g of shank loading.
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PURPOSE: This study aimed to examine the relationship between performance-related factors and physical abilities in Korean national bobsled and skeleton athletes.METHODS: Sixteen bobsled and skeleton athletes who participated in the 2018 Pyeongchang Winter Olympics as a Korean national team volunteered to participate in this study. The participants were evaluated in terms of performance-related factors, including anaerobic power, 5 bound jump (5 BJ), and sprinting speed by sections, and physical abilities, including isokinetic strength, 1 repetition maximum (1 RM) strength, body composition, anthropometry, and agility. Stepwise selection of multiple regression analyses was used to investigate the relationship between performance-related factors and physical ability.RESULTS: Statistically significant correlations were observed between anaerobic power, sprinting speed by sections, 5 BJ and chest, isokinetic strength (knee, 180°/s), deadlift, and side-step.CONCLUSIONS: The results of this study show that the performance of Korean national bobsled and skeletal athletes is related to upper and lower body strength and agility. Thus, future training programs for bobsled and skeletal athletes should focus on improving strength and agility for performance enhancement.
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Synopsis We review the two-joint link model of mono- and bi-articular muscles in the human branchium and thigh for applications related to biomechanical studies of tetrapod locomotion including gait analyses of humans and non-human tetrapods. This model has been proposed to elucidate functional roles of human mono- and bi-articular muscles by analyzing human limb movements biomechanically and testing the results both theoretically and mechanically using robotic arms and legs. However, the model has not yet been applied to biomechanical studies of tetrapod locomotion, in part since it was established based mainly on mechanical engineering analyses and because it has been applied mostly to robotics, fields of mechanical engineering, and to rehabilitation sciences. When we discovered and published the identical pairs of mono- and bi-articular muscles in pectoral fins of the coelacanth fish Latimeria chalumnae to those of humans, we recognized the significant roles of mono- and bi-articular muscles in evolution of tetrapod limbs from paired fins and tetrapod limb locomotion. Therefore, we have been reviewing the theoretical background and mechanical parameters of the model in order to analyze functional roles of mono- and bi-articular muscles in tetrapod limb locomotion. Herein, we present re-defined biological parameters including 3 axes among 3 joints of forelimbs or hindlimbs that the model has formulated and provide biological and analytical tools and examples to facilitate applicable power of the model to our on-going gait analyses of humans and tetrapods.
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Background Synchronized arm and leg motion are characteristic of human running. Leg motion is an obvious gait requirement, but arm motion is not, and its functional contribution to running performance is not known. Because arm-leg coupling serves to reduce rotation about the body’s vertical axis, arm motion may be necessary to achieve the body positions that optimize ground force application and performance. Research question Does restricting arm motion compromise performance in short sprints? Methods Sprint performance was measured in 17 athletes during normal and restricted arm motion conditions. Restriction was self-imposed via arm folding across the chest with each hand on the opposite shoulder. Track and field (TF, n=7) and team sport (TS, n=10) athletes completed habituation and performance test sessions that included six counterbalanced 30 m sprints: three each in normal and restricted arm conditions. TS participants performed standing starts in both conditions. TF participants performed block starts with extended arms for the normal condition and elevated platform support of the elbows for the crossed-arm, restricted condition. Instantaneous velocity was measured throughout each trial using a radar device. Average sprint performance times were compared using a Repeated Measures ANOVA with Tukey post-hoc tests for the entire group and for the TF and TS subgroups. Results The 30 m times were faster for normal vs. restricted arm conditions, but the between-condition difference was only 1.6% overall and < 0.10 s for the entire group (4.82±0.46 s vs. 4.90±0.46 s, respectively; p<0.001) and both TF (4.55±0.34 vs. 4.63±0.32 s; p<0.001) and TS subgroups (5.01±0.46 vs. 5.08±0.47 s; p<0.001). Significance Our findings suggest that when arm motion is restricted, compensatory upper body motions can provide the rotational forces needed to offset the lower body angular momentum generated by the swinging legs. We conclude that restricting arm motion compromised short sprint running performance, but only marginally.
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The purpose of this study was to clarify the characteristics of the arm swing movements of upper grade elementary school children during sprinting from the viewpoint of gender and differences in sprinting ability. Fifty-three children were asked to run 50 m and filmed from the side with a video camera. The subjects were then classified into 3 groups on the basis of their 50-meter sprinting time: an Excellent group (Group E), a Poor group (Group P), and an Average group (Group A). Kinematic data for the arm swing movements were then calculated and compared according to gender and differences in sprinting ability. The main results were as follows. 1) A gender difference in upper arm movement was found in the minimum segment angle of the upper arm: girls swung their arms more forward than boys, even when groups with similar sprinting times were compared. 2) When differences in upper arm movement were examined for each gender, it was found that the boys in group E showed significantly larger differences than those in groups A and P, and that group E swung their arms back and forth more widely than the other groups. With regard to upper arm angular velocity, which is an index of “arm swing speed”, group E group showed a significantly larger value than group P, and group E showed a faster backward arm swing. On the other hand, no such tendency was observed in girls, and no significant difference was found among the 3 groups with different sprinting speeds. 3) In terms of gender differences in elbow joint movement, there were no significant differences in either angle or angular velocity between boys and girls. 4) When the difference in elbow joint movement was examined for each gender, the maximum angle for girls in group E was significantly greater than that for girls in group A, but there were no significant differences in other areas. The above results indicate that the concepts of “swinging the arms back and forth significantly” and “swinging the arms fast”, which have been considered central for teaching during sprinting, are applicable to boys but not necessarily to girls. Furthermore, the concept of “maintaining elbow flexion” was not supported for both sexes.
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Wearable resistance (WR) in the form of weighted vests and shorts enables movement specific sprint running to be performed under load. The purpose of this study was to determine the acute changes in kinematics and kinetics when an additional load equivalent to 3% body mass (BM) was attached to the anterior or posterior surface of the lower limbs during sprint running. Nineteen male rugby athletes (age: 19.7 ± 2.3 years; body mass: 96.1 ± 16.5 kg; height: 181 ± 6.5 cm) volunteered to participate in the study. Subjects performed six 20 m sprints in a randomized fashion wearing no resistance or 3%BM affixed to the anterior (quadriceps and tibialis anterior) or posterior (hamstring and gastrocnemius) surface of the lower limbs (two sprints per condition). Optojump and radar were used to quantify sprint times, horizontal velocity, contact and flight times, and step length and frequency. A repeated measures analysis of variance with post hoc contrasts was used to determine differences (p ≤ 0.05) between conditions. No significant differences were found between the anterior and posterior WR conditions in any of the variables of interest. There was no significant change in sprint times over the initial 10 m, however the 10 to 20 m split times were significantly slower (-2.2 to -2.9%) for the WR conditions compared to the unloaded sprints. A significant change in the relative force-velocity (F-v) slope (-10.5 to -10.9%) and theoretical maximum velocity (V0) (-5.4 to -6.5%) was found, while a non-significant increase in theoretical maximum force (F0) (4.9 to 5.2%) occurred. WR of 3%BM may be a suitable training modality to enhance sprint acceleration performance by overloading the athlete without negatively affecting sprint running technique.
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Ten male recreational runners ranging in age from 20 to 32 years were filmed using 3-D cinematography while running on a treadmill at 3.8 m/s, 4.5 m/ s, and 5.4 m/s. The 3-D segment endpoint data were entered into a computer program that computed the segmental contributions to the upward and forward propulsive impulses on the body (lift and drive, respectively) and to the vertical component of angular momentum (Hz). The results of two subjects who demonstrated asymmetrical arm action are discussed in detail and compared with the mean results computed over all subjects. The results revealed that the arms possess the potential to compensate for each other and for asymmetries elsewhere in the body.
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The aim of this study was to compare the kinetic and kinematic parameters of standing and crouch sprint starts. Parallel starts (PS), false starts (FS), jump starts (JS) and crouch starts (3PS) were compared. Eighteen participants performed each start on a force plate and six infrared cameras captured the three-dimensional coordinates of 36 retro-reflective markers. Performance during a five-metre sprint (T5m) was analysed. Duration of the start phase (Tstart), mean values of horizontal and total ground reaction forces (GRFs) (Fx_mean and Ftot_mean), ratio of force (RF), maximal power (Pmax) and kinetic energy (KE) of each limb were calculated. Significant differences were found for T5m, Tstart, KE, Pmax, Fx_mean, Ftot_mean and RF for the crouch start compared to the other starts (P ≤ 0.05). Significant correlations were found between T5m and Tstart (r = 0.59; P ≤ 0.001), and T5m and Pmax, Fx_mean and RF (−0.73 ≤ r ≤ −0.61; P ≤ 0.001). To conclude, the crouch start resulted in the best performance because Tstart was shorter, producing greater Pmax, Fx_mean with a more forward orientation of the resultant force. Greater KE of the trunk in each start condition demonstrated the role of the trunk in generating forward translation of the centre of mass (CM).
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The arm-swing motion is important for coordinated lower limb movement during a fast sprint and is composed of three-dimensional scapulothoracic and glenohumeral joint motion. Here, we aimed to clarify the role of the scapula during the initiation of a sprint running when sprinter run with high horizontal acceleration. Ten sports-active students participated in four 5-m dashes, with scapular constraint using non-elastic therapy tape (constraint condition) and without scapular constraint (free condition). The sprinting kinematics was assessed by a 16-camera motion capture system. In the constraint condition, the 2-m sprint time was significantly longer than that in the free condition. At the instants of foot-contact and take-off during the first step, no significant difference in the humerothoracic flexion angle was seen between these two conditions. In contrast, at the instants of foot-contact and take-off during the first step, the humerothoracic extension angle in the constraint condition was significantly smaller than that in the free condition. The forward leaning vector angle of center of mass during the first step was significantly greater than that in the constraint condition. Although no significant difference in hip extension and foot forward leaning angles was seen at the instant of foot contact during the first step between the two conditions, at the instant of take-off, the hip extension and foot forward leaning angles in the constraint condition were significantly smaller than those in the free condition. Therefore, scapular behavior in first accelerated running contributes to larger upper- and lower-limb motions and facilitates coordinating whole-body balance for a fast sprint.
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Coaches’ knowledge of drills and their specificity to sprint movement patterns and muscle activations have become increasingly important. Drills are used to encourage the development of optimal movement and coordination. They are prescribed to help the athlete develop sprint technique, and it is generally assumed that the drills are the parts within a whole-part-whole learning strategy. Previous literature has suggested some drills may be questionable as they may not replicate the muscle activations or movement pattern of sprinting. A total of 209 coaches completed an online questionnaire, which examined coaches’ choice of drills; reasons for using each drill and reasons for changing drills used. The results were analysed using qualitative and quantitative methods. Results showed that coaches believed that drills are a vital part of training to improve performance but that they should be specific to sprinting technique.
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Ten male recreational runners were filmed using three-dimensional cinematography while running on a treadmill at 3.8 m/s, 4.5 m/s, and 5.4 m/s. A 14-segment mathematical model was used to examine the contributions of the arms to the total-body angular momentum about three orthogonal axes passing through the body center of mass. The results showed that while the body possessed varying amounts of angular momentum about all three coordinate axes, the arms made a meaningful contribution to only the vertical component (Hz). The arms were found to generate an alternating positive and negative Hz pattern during the running cycle. This tended to cancel out an opposite Hz pattern of the legs. The trunk was found to be an active participant in this balance of angular momentum, the upper trunk rotating back and forth with the arms and, to a lesser extent, the lower trunk with the legs. The result was a relatively small total-body Hz throughout the running cycle. The inverse relationship between upper- and lower-body angular momentum suggests that the arms and upper trunk provide the majority of the angular impulse about the z axis needed to put the legs through their alternating strides in running.
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Ten male recreational runners were filmed using three-dimensional cinematography while running on a treadmill at 3.8 m/s, 4.5 m/s, and 5.4 m/s. A 14-segment mathematical model was used to examine the influence of the arm swing on the three-dimensional motion of the body center of mass (CM), and on the vertical and horizontal propulsive impulses (“lift” and “drive”) on the body over the contact phase of the running cycle. The arms were found to reduce the horizontal excursions of the body CM both front to back and side to side, thus tending to make a runner's horizontal velocity more constant. The vertical range of motion of the body CM was increased by the action of the arms. The arms were found to make a small but important contribution to lift, roughly 5–10% of the total. This contribution increased with running speed. The arms were generally not found to contribute to drive, although considerable variation existed between subjects. Consistent with the CM results, the arms were found to reduce the changes in forward velocity of the runner rather than increasing them. It was concluded that there is no apparent advantage of the “classic” style of swinging the arms directly forward and backward over the style that most distance runners adopt of letting the arms cross over slightly in front. The crossover, in fact, helps reduce side-to-side excursions of the body CM mentioned above, hence promoting a more constant horizontal velocity.
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Background: Although lower-body strength is correlated with sprint performance, whether increases in lower-body strength transfer positively to sprint performance remain unclear. Objectives: This meta-analysis determined whether increases in lower-body strength (measured with the free-weight back squat exercise) transfer positively to sprint performance, and identified the effects of various subject characteristics and resistance-training variables on the magnitude of sprint improvement. Methods: A computerized search was conducted in ADONIS, ERIC, SPORTDiscus, EBSCOhost, Google Scholar, MEDLINE and PubMed databases, and references of original studies and reviews were searched for further relevant studies. The analysis comprised 510 subjects and 85 effect sizes (ESs), nested with 26 experimental and 11 control groups and 15 studies. Results: There is a transfer between increases in lower-body strength and sprint performance as indicated by a very large significant correlation (r = -0.77; p = 0.0001) between squat strength ES and sprint ES. Additionally, the magnitude of sprint improvement is affected by the level of practice (p = 0.03) and body mass (r = 0.35; p = 0.011) of the subject, the frequency of resistance-training sessions per week (r = 0.50; p = 0.001) and the rest interval between sets of resistance-training exercises (r = -0.47; p ≤ 0.001). Conversely, the magnitude of sprint improvement is not affected by the athlete's age (p = 0.86) and height (p = 0.08), the resistance-training methods used through the training intervention, (p = 0.06), average load intensity [% of 1 repetition maximum (RM)] used during the resistance-training sessions (p = 0.34), training program duration (p = 0.16), number of exercises per session (p = 0.16), number of sets per exercise (p = 0.06) and number of repetitions per set (p = 0.48). Conclusions: Increases in lower-body strength transfer positively to sprint performance. The magnitude of sprint improvement is affected by numerous subject characteristics and resistance-training variables, but the large difference in number of ESs available should be taken into consideration. Overall, the reported improvement in sprint performance (sprint ES = -0.87, mean sprint improvement = 3.11 %) resulting from resistance training is of practical relevance for coaches and athletes in sport activities requiring high levels of speed.
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Selected kinematic variables in the performance of the Gold and Silver medalists and the eighth-place finisher in the men's 200-meter sprint final at the 1984 Summer Olympic Games were investigated. Cinematographic records were obtained for all track running events at the Games, with the 200-meter performers singled out for initial analysis. In this race, sagittal view filming records (100 fps) were collected at the middle (125-meter mark) and end (180-meter mark) of the performance. Computer-generated analysis variables included both direct performance variables (body velocity, stride rate, etc.) and upper and lower body kinematics (upper arm position, lower leg velocity, etc.) that have previously been utilized in the analysis of elite athlete sprinters. The difference in place finish was related to the performance variables body horizontal velocity (direct), stride rate (direct), and support time (indirect). The critical body kinematics variables related to success included upper leg angle at takeoff (indirect), upper leg velocity during support (direct), lower leg velocity at touchdown (direct), foot to body touchdown distance (indirect), and relative foot velocity at touchdown.