Shoulder Instability Rehabilitation and Return to Sport

Abstract

The shoulder is an inherently unstable ball and socket joint that places that places high demands on the glenohumeral joint, so the rehabilitation process following an arthroscopic anterior shoulder stabilization surgery must be detailed and individualized. The rehabilitation process is divided into 5 phases, with each phase becoming more aggressive in exercise protocol and therapy in order to regain strength and ROM. The ultimate goal is to restore full strength and ROM and to slowly incorporate sports-related activity and training as the patient is ending the rehabilitation process. One vital aspect of the recovery process is to ensure the athlete is never pushed through painful ROM or exercises.

Keywords: arthroscopy, glenohumeral, instability, range of motion, rotator cuff, sport rehabilitation.

Phase 1: Protective Phase, 0 to 2 Weeks

( Video 4A.1 ) During the rotective phase, the primary goals are to reduce and minimize pain and swelling, prevent inhibition of dynamic stabilizers of the shoulder joint, and gradually control passive ROM (PROM) so as not to cause undue stress to the surgical repair. As demonstrated, pain can lead to joint instability, muscle inhibition, and weakness. More recently, pain has been shown to inhibit rotator cuff activation during specific exercises for shoulder strengthening ( ). Pain has also been shown to affect muscle coordination in the shoulder, which is why it is essential to minimize it as quickly as possible ( ).

• Video 4A.1

  Postoperative rehabilitation: anterior stabilization.

After an anterior stabilization procedure, it is critical to respect ROM precautions and guidelines especially in the early phases. The purpose of the surgery is to provide stability to the joint, which can be compromised with PROM that is too early or too aggressive. Even subfailure strains can produce enough force to elongate and produce laxity in shoulder ligaments. This laxity, especially in the IGHL, can contribute to acquired shoulder instability ( ). Controlled motion in this phase must be respected in order to maintain capsular and ligamentous constraint. The position of abduction and external rotation (ER) produces the most stress in the anterior shoulder in both a native shoulder as well as shoulders with anterior labral repair ( ). PROM is initiated in the scapular plane, which minimizes stress on passive and active shoulder stabilizers. showed that the edges of simulated Bankart lesions were kept approximated from full internal rotation (IR) to 30 degrees of ER.

Exercises in this phase are focused on scapular activation and postural correction as well as distal elbow, hand, and wrist movement. Submaximal isometric contractions of the scapular muscles are allowed, but we recommend against rotator cuff activation during this phase. Even though the rotator cuff is not affected during surgery, it is the experience of the author that early rotator cuff exercises can irritate the joint during the initial postoperative period. Distal muscle activation can help improve circulation and help minimize any swelling that has migrated beyond the elbow.

Immobilization

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  A sling is to be worn at all times during the first 2 weeks.

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  The sling can be taken off at home for exercise after week 2 and can be discharged at home starting week 4.

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  The sling is to be worn outside the home for 6 weeks in all uncontrolled environments.

Range of Motion Progression

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  Forward elevation: 0→ 90 degrees

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  External rotation: 0→30 degrees (shoulder positioned in scapular plane)

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  ER at 90 degrees shoulder abduction: contraindicated

Exercises

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  Scapular isometrics

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  Pendulums

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  PROM shoulder to 90 degrees

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  AROM elbow, wrist, hand

Modalities

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  Cryotherapy and compression five times a day. (The author prefers the Game Ready system shoulder attachment.)

Phase 2: 3 to 6 Weeks

Progression to phase 2 is possible when pain is minimized, PROM shoulder flexion to 90 degrees has been achieved, and patients demonstrate good understanding of posture and precautions. During this phase, activation of the rotator cuff and other dynamic stabilizers is important to support the glenohumeral joint. It is important that the local stabilizers are initiated before global musculature, which will help maintain proper centralization of the humeral head in the glenoid. The rotator cuff muscles help stabilize the glenohumeral joint in all planes of movement. In flexion, the stabilizers are the infraspinatus, supraspinatus, and latissimus dorsi. In extension, the subscapularis and supraspinatus stabilize. In ER, the subscapularis is the stabilizer, and in abduction, the stabilizers are the infraspinatus and subscapularis ( ). Without proper activation of these muscles, compromised GH stability would be imminent. Scapular protraction is not recommended until week 6 because of the excessive strain that it places on the anterior band of the IGHL ( ).

During this phase, scapulohumeral rhythm should also be emphasized. With the patient in a sidelying position, the therapist can palpate scapular musculature and provide manual resistance while cuing the patient to activate appropriate muscles. This manual resistance can be progressed to scapular proprioceptive neuromuscular facilitation (PNF) in the sidelying position. Closed kinetic chain activation can also be initiated in this phase. This type of exercise allows for distal fixation with proximal muscle activation while promoting centralization of the humeral head into the glenoid through compression.

Phase 3: 6 to 12 Weeks

The goals of this phase are to restore full shoulder ROM and normal scapulohumeral rhythm. Upper extremity strength should continue to be progressed, and by 12 weeks, patients are expected to have full pain-free AROM. If this is not achieved, consultation with the referring physician may be necessary to address limiting factors. AROM should be progressed from 0 degrees of abduction to the 90-degree/90-degree position by the end of this phase. Gentle glenohumeral joint mobilizations (grades II and III) can help restore mobility but should be used with caution because we do not want to stretch the joint capsule beyond its physiologic limit, on the other hand we do want to protect the integrity of the anterior capsule.

As strengthening progresses throughout this phase, caution is taken to avoid rotator cuff irritation, which can impede progress. Using current evidence and electromyographic (EMG) studies, careful exercise progression is used to advance strength with focus on rotator cuff and scapular muscles. Sidelying ER with a towel roll under the arm has been shown to elicit high levels of infraspinatus activation and is helpful in enhancing lower and mid trapezius activity ratios ( ). Using a towel roll has anatomic, neurologic, and biomechanical benefits. By using a towel roll under the arm for rotation exercises, a reduction is seen in the amount of compensatory abduction force through reciprocal inhibition, which will assist in improved rotator cuff isolation. Also, by raising the arm to about 30 degrees of abduction with a towel roll, there is decreased tension on the rotator cuff muscles ( ). During forward elevation, attention should be paid to the quality of movement, in particular shoulder shrug. If this is noticed, patients should stay within the “shrug-free” zone of movement until adequate dynamic GH centralization is achieved.

Scapulothoracic muscle strengthening is emphasized in this phase. Shoulder elevation in the scapular plane is introduced (30 degrees anteriorly from the frontal plane) as scaption maintains the humeral head into the glenoid and promotes shoulder stability ( ). Between 120 and 150 degrees of elevation, scaption elicits high lower trapezius and serratus anterior muscle activity. Rowing is an optimal exercise for middle trapezius and rhomboid activation, and prone extension is also optimal for middle trapezius activity ( ).

Serratus anterior activation can also commence in this phase, which will help to restore normal scapulohumeral rhythm. The push-up plus and dynamic hug both elicit high EMG activity ( ). Two-arm press-ups in a quadruped position are a safe way to start closed-chain serratus activation. This can be progressed to tripod press-ups and then addition of an unstable surface. Finally, the patient can progress into a full plank tripod, double-arm and then single-arm press-up, which has been shown to have the highest EMG activity ( ).

As full ROM is achieved, overhead movement patterns can be initiated, including PNF. These exercises can be started in the supine position and gradually progressed to standing and then against resistance. PNF can be used to help increase ROM, increase muscular strength and power, and increase athletic performance ( ).

Phase 4: 12 to 18 Weeks

During phase 4, emphasis is on building the foundation for the athlete to return to her or his respective sport. Overhead strengthening and end range stability are focuses while maintaining previously established scapular rhythm and rotator cuff activation. This phase concentrates on whole-body strength and progresses to whole-body linking activities.

Phase 6: Weeks 18+

This phase focuses on sports-specific training and depends on the sport to which the athlete is returning. Baseball players will progress to a return to throwing program, tennis players to an interval tennis program, and so forth. These programs are structured to gradually apply increased load to the shoulder joint while building flexibility and endurance at the same time. The patient should consult his or her physical therapist with any onset of pain during this progression.