Tennis and Squash: Unilateral Growth and Scapular Dyskinesis
In short
Repetitive unilateral overhead strokes in tennis and squash cause scapular dyskinesis in growing youth. Discover corrective sports physiotherapy.
In this guide (6 sections)
Unilateral growth asymmetry and scapular dyskinesis represent prevalent musculoskeletal adaptations in adolescent tennis and squash players aged 11 to 16 years. Executing thousands of repetitive high-velocity overhead serves, forehand drives, and backhand volleys exclusively with the dominant arm during pubertal growth spurts alters normal osteochondral and muscular development. Unchecked unilateral loading induces humeral retroversion, dominant shoulder depression, tight posterior capsule, and scapular dyskinesis (SICK scapula), predisposing young athletes to rotator cuff tears and impingement.
Domestic and Cultural Indian Realities
With India emerging as an international force in racket sports, junior tennis and squash academies operate intense, year-round specialised regimens. Young players often hit 500 to 800 balls daily from an early age, training 5 to 6 days a week without structured bilateral cross-training or posterior shoulder conditioning. When shoulder stiffness or neck soreness emerges, coaches frequently advise players to stretch aggressively into overhead positions, which worsens anterior capsular laxity and accelerates subacromial impingement.
Clinical Biomechanics and Physeal Physiology
During adolescent growth, the proximal humeral physis contributes 80 percent of the longitudinal growth of the humerus. Repetitive external rotation torque during the late cocking phase of serving causes osseous remodeling, increasing humeral retroversion in the dominant arm. Muscularly, the dominant pectoralis minor and latissimus dorsi become markedly shortened, while the serratus anterior and lower trapezius become inhibited. This muscle imbalance tilts the scapula anteriorly and downward, narrowing the subacromial space.
Clinical Assessment and Diagnostic Differentiation
Clinical assessment evaluates scapular kinematics using the Scapular Dyskinesis Test (visual observation of winging or dysrhythmia during active arm lowering). Total arc of rotational motion (internal plus external rotation at 90 degrees of abduction) is measured to detect Glenohumeral Internal Rotation Deficit (GIRD): a loss of internal rotation exceeding 18 to 20 degrees compared to the non-dominant shoulder indicates pathological posterior capsular contracture.
Targeted Rehabilitation and Loading Protocols
Rehabilitation addresses the entire kinetic chain. Posterior shoulder tightness is managed through sleeper stretches and cross-body adduction stretches, avoiding aggressive anterior stretches. Scapular re-education emphasizes serratus anterior activation (such as push-up plus progressions) and lower trapezius strengthening. Kinetic chain sequencing drills integrate lead-hip internal rotation and thoracic extension to diminish shoulder torque during serving.
Side-Lying Sleeper Stretch for Posterior Capsule Mobility
Objective: Safely restore glenohumeral internal rotation and stretch the tight posterior shoulder capsule in the dominant racket arm
- 1Lie on your affected dominant side on a cushioned treatment mat, with your head comfortably supported on a pillow.
- 2Position your dominant upper arm flat on the mat at 90 degrees to your body, with your elbow bent to 90 degrees so your forearm points toward the ceiling.
- 3Place your opposite hand gently on the back of your dominant wrist.
- 4Gently press your dominant forearm downward toward the mat into internal rotation until you feel a firm, comfortable stretch in the back of your shoulder.
- 5Hold the static stretch for 30 seconds while breathing steadily, avoiding any sharp anterior shoulder pinching.
| Dyskinesis Pattern | Visual Scapular Observation | Underlying Muscular Imbalance and Care |
|---|---|---|
| Type I: Inferior Angle Prominence | Inferior medial border of scapula tilts posteriorly away from the rib cage | Tight pectoralis minor; weak lower trapezius and serratus anterior; posterior tilting drills |
| Type II: Medial Border Prominence | Entire medial border of scapula lifts off the thoracic wall (winging) | Severe serratus anterior weakness and long thoracic nerve traction; push-up plus |
| Type III: Superior Shrugging | Early compensatory elevation of the entire scapula during initial arm elevation | Upper trapezius hyperactivity and rotator cuff inhibition; scapular depression drills |
Red Flags and Specialist Escalation
Immediate orthopaedic consultation is required if the young athlete exhibits true glenohumeral joint subluxation, a positive O'Brien active compression test indicating a superior labral anterior-to-posterior (SLAP) tear, visible muscle wasting in the supraspinatus or infraspinatus fossae, or radiating numbness into the arm. These findings suggest labral pathology or suprascapular nerve entrapment requiring MRI arthrogram imaging.
Frequently Asked Questions
Can scapular dyskinesis and shoulder pain be managed without stopping tennis or squash?
Yes, in early stages, modifying overhead serving volume while actively retraining scapular stabilizers, posterior capsular mobility, and kinetic chain hip drive allows young racket athletes to maintain training without complete sports withdrawal.
Do junior tennis players in India need a doctor referral to see a sports physiotherapist?
BookPhysio.in does not ask for a doctor referral. Under the National Commission for Allied and Healthcare Professions (NCAHP) Act 2021, registered physiotherapists are recognized as autonomous primary contact practitioners. You can book directly with sports physiotherapists and pay directly per session.
Related condition guides
Related recovery guides & articles
BookPhysio.in Editorial Team
The BookPhysio.in editorial team writes and maintains this content, checking it against reliable clinical sources. Content follows our medical review policy: general information only, and no page claims a clinical review until a named registered physiotherapist has signed it off.
Read our medical review policy