- Phases of Throwing:
- wind up
- early cocking: deltoid and rotator cuff are active;
- late cocking phase:
- muscle activity:
- shoulder is placed in hyper-external rotation;
- pectoralis major and the subscapularis (shoulder adductors) and the latissimus and teres major (internal rotators) are placed under eccentric stress;
- supraspinatus is also active during this stage (by EMG analysis);
- biceps contracts (for elbow flexion)
- recurrent anterior instability:
- posterior glenohumeral pain and anterior subluxation occurs during late cocking and early acceleration phases;
- w/ complaints of a painful clicking (dead arm syndrome) during this phase, consider recurrent anterior instability;
- Shoulder instability in the overhand or throwing athlete.
- posterior impingement
- SLAP lesion - type II
- quadrilatateral space syndrome
- also note that the rare quadrilatateral space syndrome occurs when the arm is abducted and exteranally rotated
and is characterized by positional compression of the posterior humeral circumflex artery and the axillary nerve;
- Rotator cuf and postero-superior glenoid labrum injury associated with increased glenohumeral motion: a new site of impingment syndrome
- Posterosuperior glenoid impingement of the shoulder: findings at MR imaging and MR arthrography with arthroscopic correlation.
- A Cadaveric Model of the Throwing Shoulder: A Possible Etiology of Superior Labrum Anterior-to-Posterior Lesions.
- Arthroscopic findings in the overhand throwing athlete: evidence for posterior internal impingement of the rotator cuff.
- Impingement of the deep surface of the supraspinatus tendon on the posterosuperior glenoid rim: an arthroscopic study.
- Anterior instability increases superior labral strain in the late cocking phase of throwing.
- acceleration phase:
- pectoralis, latissimus, serratus, and subscapularis are active;
- rotator cuff and biceps are inactive;
- follow through:
- most activity deliberate;
- stresses posterior capsule;
- throwing athletes with symptomatic internal rotation deficits should have an intensive posterior capsular stretching program;
- patients that fail to respond to streching may consider an arthroscopic posterior capsular release;
- reference: Glenohumeral range of motion deficits and posterior shoulder tightness in throwers with pathologic internal impingement.
- pain with follow through (phase 3) may indicate posterior instability;
- rotator cuff is eccentrically loaded mainly during this phase;;
- biceps contracts to prevent elbow hyperextension;
- Specific Conditions:
- SLAP lesions
- Thoracic Outlet
- Arterial and Venous Injuries in Athletes. Findings and Their Effect on Diagnosis and Treatment
- Evaluation of a new treatment strategy for Paget-Schroetter syndrome: spontaneous thrombosis of the axillary-subclavian vein.
- most often affects young, active adults who are engaged in sports activities or whose professions require repetitive arm movements
- Comprehensive surgical management of competitive athlete with effort thrombosis of the subclavian vein (Paget-Schroetter syndrome).
- Little League Shoulder: (epiphysiolysis of the proximal humerus);
- osteochondrosis of the proximal humeral epiphysis due to overuse from throwing;
- radiographs show physeal widening, fragmentation, and/or sclerosis of the lateral aspect of the proximal humeral physis;
- lateral metaphyseal fragmentation and/or sclerosis
- Little Leaguer’s Shoulder. A Report of 23 Cases.
- Muscle Strength and Range of Motion in Adolescent Pitchers With Throwing-Related Pain. Implications for Injury Prevention
The diagnosis and treatment of anterior instability in the throwing athlete. An analysis of 100 symptomatic baseball players. Am J. Sports Med. 1978;6:62-67.
An EMG analysis of the shoulder in pitching. A special report.
Dynamic electromyographic analysis of the throwing shoulder with glenohumeral instability.
Electromyographic Analysis and Phase Definition of the Overhead Football Throw.
Original Text by Clifford R. Wheeless, III, MD.
Last updated by Data Trace Staff on Saturday, June 23, 2012 8:34 pm