Injuries
in the Racquet Sports
- Racquet sports, especially
lawn tennis and badminton have been gaining popularity in Asian countries
like India.
- With this increase in
popularity, the injury rate in the sport has also increased.
- The injury rate in tennis
varies from 0.04 injuries/1000 hours to 21.5 injuries/1000 hours
- Pluim BM, Staal JB (2006)
- Different overhead sports show different characteristics, but have similar movement patterns.
- In each, the dominant upper
limb is subjected to repeated overhead movements.
- Torres
RR, Gomes JL (2009), Wilk KE, Meister K (2002)
Racquet
Sports – Biomechanics
- The mechanics of an overhead
stroke or serve in racquet sports are similar to that of an overhead
throw, wherein the shoulder has to be lax enough to allow the extra
degrees of external rotation necessary for an adequate serve and at the
same time has to be stable enough to prevent any subluxations.
- Craig
A. (1995)
- This delicate balance between
mobility and stability is referred to as ‘throwers paradox’ and if
compromised, can lead to injury.
- Wilk
KE, Meister K (2002)
- A racquet serve/stroke is a
combination of true gleno-humeral rotation, trunk hyperextension and
scapulo-thoracic motion.
- The cocking phase maintains
the dominant arm in 90° abduction and external rotation which reaches a
maximum of 172° to 180° during the late cocking phase.
- Fleisig
GS, Barrentine SW (1996), Fleisig G, Nicholls R (2003), van der
Hoeven H, Kibler WB. (2006)
- It ends with internal rotation
and forward flexion of the dominant shoulder along with upper torso and
pelvic rotation during the follow through phase.
- Jason
A. (2007)
The
GIRD:
- Each phase places an
asymmetric load between the two shoulders, with the dominant shoulder
exposed to maximum stress. Jason
A. (2007)
- Studies have shown a
significant difference in the gleno-humeral internal rotation range of
motion between dominant and non-dominant shoulders of overhead sport
players.
- Shimpi AP,
Shah B (2015). Shah N, Shimpi AP (2016)
- This is defined as
‘Gleno-humeral internal rotation deficit’ (GIRD), which is the loss in
degrees of the gleno-humeral internal rotation of the throwing shoulder
compared with the non-throwing shoulder.
- Burkhart
SS, Morgan CD, Kibler WB. (2003)
- An accepted level of GIRD is
less than 20° deficit of gleno-humeral internal rotation or less than 10%
deficit of the total rotation seen in throwing shoulder as compared to the
non-throwing shoulder.
- Burkhart
SS, Morgan CD, Kibler WB. (2003)
- The scapula provides a stable
base to the movement of humeral head during an overhead motion. The
stability of the scapula becomes important in these movement patterns. Jason A. (2007)
SICK
Scapula….
- An asymmetry develops in the
scapular posture of overhead athletes like tennis players, where the
dominant scapula is more protracted than the non-dominant side.
- Oyama
S, Myers JB (2008). Shimpi AP,
Shah B (2015)
- The acronym SICK scapula
(scapular malposition, inferior medial border prominence, coracoid pain
and malposition and dyskinesis) is used to describe this asymmetry of
scapula.
- Burkhart
SS, Morgan CD, Kibler WB (2003)
- This asymmetry is accentuated
in unilateral overhead athletes who use their dominant shoulder
repetitively in a forceful manner.
- Oyama
S, Myers JB (2008). Shimpi AP,
Shah B (2015)
- Many authors suggest that this
increased scapular protraction along with GIRD, increases the likelihood
of shoulder injuries in these players.
- Wilk
KE, Obma P (2009). Thomas SJ, Swanik KA (2010)
- Shoulder girdle injuries
account for 17.27% in racquet players with 43.4% of elite tennis players
presenting with scapular dyskinesia.
- Borsa
PA, Laudner KG (2008). Kondric M, Matkovic BR (2011)
- Studies have also shown a
positive association between a dyskinetic scapula with posterior shoulder
tightness and GIRD in the dominant arm of overhead players. Laudner
KG, Moline MT (2010). McClure P, Greenberg E (2012)
- During the follow through
phase, the scapula has to protract around the thoracic wall in order to
help dissipate the energy.
- Kibler
WB. (1991). Voight ML, Thomson BC. (2000)
- In the presence of
considerable GIRD, the players have to bring about increased scapular
protraction to compensate for the reduced internal rotation in order to
maintain the velocity of the overhead stroke.
- Thomas
SJ, Swanik KA (2010). Shimpi AP,
Shah B (2015)
- With time, this continuous
stress causes soft tissue adaptations and leads to weakness of the
scapular stabilizers, mainly the lower fibres of rhomboids causing an
upward rotation.
- Thomas
SJ, Swanik KA (2010). Shimpi AP,
Shah B (2015)
- Thus, the scapula cannot
provide a stable base of support for the rotator cuff to function, which
reduces its efficiency and increases stress on the static restraints of
the dominant shoulder. Thomas SJ,
Swanik KA (2010)
- So, rather than compressing
the humeral head into the glenoid fossa, the rotator cuff pulls the
scapula upward and laterally resulting in greater scapular protraction and
external rotation.
- Kibler
WB. 1998. Shimpi AP, Shah B (2015). Shah N, Shimpi AP
(2016)
Why
Scapular Perspective?
- During the follow through
phase of an overhead motion, the shoulder joint is subjected to
distractive forces of up to 750N which is mainly resisted by the
postero-inferior capsule.
- van der Hoeven H, Kibler WB. (2006)
- With repetitive loading, the
posterior capsule is said to undergo micro trauma causing hypertrophy and
increased fibroblastic activity during the healing process, leading to
contracture and thickening of the capsule. Thomas
SJ, Swanik KA (2010)
- This reduces the capsular
pliability causing restriction of internal rotation, extension and
horizontal adduction.
- van der Hoeven H, Kibler WB. (2006). Thomas SJ, Swanik KA (2010). Shimpi AP, Shah B (2015)
- A posterior capsule stretching
program incorporated in the rehabilitation and training of overhead
players is reported to reduce the incidence of GIRD.
- It also reduces the incidence
of shoulder injuries like Superior Labrum Anterior Posterior (SLAP)
lesions in these players.
- Burkhart
SS, Morgan CD, Kibler WB (2003)
- Arthroscopic studies have also
shown increased thickness and hypertrophy of capsule in the
postero-inferior recess of dominant arm of throwers and its positive
association with GIRD, external rotation and scapular upward rotation. Thomas SJ, Swanik CB (2011)
- Studies have shown that for a
4° decrease in internal rotation, there is 1cm decrease in horizontal
adduction, which is an indicator of posterior capsule tightness.
- Torres
RR, Gomes JL (2009)
- Studies also showed a
significant increase in the external rotation of the dominant shoulder
compared to non-dominant side in racquet players and when compared to
dominant side of non-racquet players.
- Shimpi AP,
Shah B (2015)
- One of the causes can be
attributed to the contracted or shortened posterior band of the inferior
gleno humeral ligament (IGHL) which primarily provides restraint to
further movement in position of maximum abduction and external rotation
during late cocking phase. Burkhart
SS, Morgan CD, Kibler WB. (2003)
- It prevents posterior
migration of humeral head, thus centering it in the glenoid fossa allowing
a normal arc of movement.
- van der Hoeven H, Kibler WB (2006)
- Arthroscopic findings in
overhead players show contractures and thickening in the zone of the
posterior band of IGHL.
- van der Hoeven H, Kibler WB (2006)
- The tethered posterior band
draws the humeral head postero-superiorly to a new point of rotation on
the glenoid, thus causing an abnormal increase in the external rotation
due to easier clearance of the greater tuberosity.
- van der Hoeven H, Kibler WB (2006)
- The postero-superior migration
of humeral head also reduces the cam effect of the humeral head and
antero-inferior humeral calcar on the antero-inferior capsule leading to
redundancy in the antero-inferior capsule, allowing hyper external
rotation of the dominant arm. Burkhart
SS, Morgan CD, Kibler WB. (2003). Burkhart SS (2007)
- Another explanation for the
increased external rotation can be possibly attributed to increased
humeral retroversion which is a common finding in players playing overhead
sports.
- Kibler
WB, Sciascia A (2012)
- This change in the humeral head causes a
shift in the arc of rotation of the dominant shoulder favoring external
rotation.
- Tokish
JM, Curtin MS (2008)
- However, the studies suggest
that the total arc of rotation remains the same, as any increase in the
external rotation will require a corresponding decrease in the internal rotation,
which will be permanent. Lintner D,
Mayol M (2007)
- There exists presence of
abnormal scapular resting position in asymptomatic racquet players on the
dominant side in the form of scapular external rotation and elevation on
the dominant side as compared to their non-dominant side.
- There also exists presence of
gleno-humeral movement dysfunction in the form of reduced internal
rotation, extension and adduction and gain in external rotation on the
dominant side.
- A comparison between symptomatic
and asymptomatic players could help determine the pathological threshold
for injury predisposition.
- ROM and scapular resting
position can be used as a screening tool for injury prevention in overhead
racquet players.
- Shimpi AP,
Shah B (2015). Shah N, Shimpi AP (2016)
Advanced
Training
- Most important is to prepare
the athlete for a long term, not just for the coming season.
- Nyland
J (2010)
- Functional exercises
simulating the athletes role and Sports Specific Scapular training is
extremely important.
- This helps in gaining an
excellent neuromuscular control and functioning.
- More useful in establishing
athletes self efficacy and confidence as movements closely resemble the
athletes sports specific movements.
- Nyland
J (2013)
- Functional training can be
achieved by training the athlete in a sports simulation by:
- A. Uni-planar training the
protractors.
- B. Uni-planar training of the
retractors.
- C.
Bi-planar motion training
- D.
Multi-planar motion training.
- E. Simulation of the game with resistive
training
- Nyland
J (2011)
- Further enhancement can be
obtained by using unstable surface like the BOSU for bodily challenges and
further enhancement.
- Wankhede
N, Shimpi A (Hypothesis)
- This can be challenged using:
- A.
Strength training on BOSU
- B. Limb and trunk
challenges
- C. Focused stability challenge
- D. Hit and serve challenges.
Summary
- Injured overhead athletes may
display more asymmetry than healthy overhead athletes, and there may be a
pathologic threshold for scapular posture asymmetry at which an asymmetry
becomes problematic. Shimpi AP, Shah B
(2015)
- Need of specific stretching
and strengthening as a part of the pre-season training of racquet athletes
to address muscular imbalances to provide optimum scapular and
gleno-humeral stability to the shoulder to endure the demands of the game.
Nyland J (2013)
- Need for advanced training to
prepare the athlete in prevention of injuries and correct the problems
before they become real problems for the athletes. Wankhede N, Shimpi A
(Hypothesis)
References:
Shimpi
AP, Bhakti S, Roshni K, Rairikar SA, Shyam A, Sancheti PK. Scapular Resting
Position and Gleno-Humeral Movement Dysfunction in Asymptomatic Racquet Players:
A Case-Control Study. Asian J Sports Med. 2015 Dec;6(4):e24053. doi: 10.5812/asjsm.24053.
Epub 2015 Dec 1. PubMed PMID: 26715968; PubMed Central PMCID: PMC4691306.
Shah NA, Shimpi AP, Rairikar SA, Ashok S, Sancheti PK. Presence of scapular dysfunction in
dominant shoulder of professional guitar players. Int J Occup Saf Ergon. 2016 Sep;22(3):422-5.
doi: 10.1080/10803548.2016.1154720. Epub 2016 Mar 29. PubMed PMID: 27023289.
https://www.ncbi.nlm.nih.gov/pubmed/27023289
Others Available on Request
