Recurrent shoulder instability among athletes: changes in quality of life,sports activity,and muscle function following open repair

Background: Recurrent anterior shoulder instability is a disabling condition in young athletes with possibly underestimated impact on quality of life and sports activity. Commonly used clinical scoring systems do not reflect the impairment of quality of life and sports activity. It was our aim to assess the return to preinjury levels of quality of life and sports activity as well as the changes in muscle function among competitive and recreational athletes. Hypothesis: Patients suffering from post-traumatic recurrent shoulder instability have to adopt their participation in sports and therefore discover a reduction in quality of life. Open stabilization procedures are able to improve shoulder function and to reduce recurrence rates. However, return to preinjury shoulder function is not guaranteed. Study design: Retrospective longitudinal cohort study on 19 consecutive athletes with recurrent, post-traumatic shoulder instability. All patients were treated with an open, capsulo-labral repair. The minimum follow-up was 24 months. Methods: Life quality (SF12) and sports activity data (Athletic Shoulder Outcome Scoring System) were retrospectively collected for the time before injury (time 1) and for the time with recurrent instability (time 2). Two years after surgical stabilization (time 3), we followed our patients with different clinical outcome scores, rotator surface EMG measurement, isokinetic muscle strength testing, and a radiological evaluation. This design of a three-step follow-up allowed for calculating the impact on quality of life and sports activity following the injury. Results: Two years after surgery, the clinical scoring systems revealed good-to-excellent results in all patients. Quality of life physical component summary remained diminished by 9.2% despite the surgical procedure and was therefore significantly lower as compared to preinjury levels (p < 0.05). Sports activity was also significantly lower at the time of follow-up (p < 0.05). In this specific procedure, external rotation was not impaired postoperatively. EMG testing showed an overall reduction of muscle activity, however not significant. Isokinetic muscle strength was significantly diminished for external rotation and shoulder abduction. Conclusions: Open reconstruction procedures for recurrent shoulder instability can restore shoulder function and stability to near-normal values. Despite good-to-excellent clinical results, there is a significant impairment of quality of life and sports activity 2 years after surgery. Muscle activity and muscle strength are diminished. Recurrent shoulder instability remains a disabling condition to the young athlete. Future strategies have to emphasize restoration of quality of life, sports activity, and muscle function.     

Does verbal and tactile feedback change EMG activity in shoulder girdle and trunk muscles during plyometric exercise in overhead athletes with and without shoulder pain?

ObjectivesTo investigate if there is a difference in muscle activity for overhead athletes before and after an intervention with correction of both core and scapula compared to no intervention and is there a difference between overhead athletes with or without shoulder pain.DesignControlled laboratory EMG study including intervention.SettingUniversity EMG laboratory.ParticipantsSixty overhead athletes, 30 with shoulder pain and 30 healthy controls were included performing plyometric rotational shoulder exercise.Main outcomesHalf of the participants received an intervention the other half were controls with no intervention. EMG muscle activity from 10 scapular, thoraco-humeral and trunk muscles were measured.ResultsThere were no significant differences in muscle activation levels between the groups with or without intervention. For the shoulder pain group, there were significant lower activity in Upper Trapezius when repeating the exercise. The shoulder pain group had significant higher activity in Pectoralis Major compared to the Healthy Control group.ConclusionsMost differences were found between the pre- and post-test. Repetition of the exercise seems to be more important than verbal and tactile instructions. Comparing the shoulder pain group with the healthy controls confirms previous findings that, pain patients recruit muscles differently from healthy persons.     

Muscle recruitment during plyometric exercises in overhead athletes with and without shoulder pain

ObjectivesTo investigate if there is a difference in muscle activity patterns during high load plyometric shoulder exercises between overhead athletes with and without shoulder pain.DesignControlled laboratory EMG study.SettingUniversity EMG Laboratory.ParticipantsSixty overhead athletes, 30 with shoulder pain and 30 healthy controls were included.Main outcome measuresThe EMG activity of Upper Trapezius (UT), Middle Trapezius (MT), Lower Trapezius (LT), Serratus Anterior (SA), Latissimus Dorsi (LD) and Pectoralis Major (PM) on the tested side and bilateral on Abdominal Obliques Externus (OE) muscles was registered with wireless surface EMG during 3 rotational plyometric shoulder exercises in 3 positions, prone, sidelying and standing.ResultsA significant higher muscle activity was found in the shoulder pain group for MT together with an overall significant higher activity in the thoraco-humeral and abdominal muscles compared to healthy controls.ConclusionsWhen rehabilitating the overhead athlete with shoulder pain, shoulder muscles together with both thoraco-humeral and abdominal muscles need to be engaged.     

Activity of shoulder girdle muscles during the perfect push-up and push-up bar exercises using different hand positions in young overhead athletes

Background

Push-up is considered as an excellent exercise for both assessment and training in athletes. However, the influence of its mode of application on activation of shoulder girdle musculature has been scantily studied by previous research in young overhead athletes.

Objectives

To investigate the activity of pectoralis major (PM) and triceps brachii (TB) muscle during push-up exercise performed on the push-up bar and perfect push-up using shoulder width (SW), narrow shoulder width (NSW) and wide shoulder width (WSW) hand positions in young overhead athletes.

Methods

24 young overhead athletes were recruited for the present study. Surface electromyography (EMG) was recorded for the PM and the TB muscles during the performance of push-up exercise on the push-up bar and perfect push-up using different hand positions (SW, NSW, and WSW). Root mean square (RMS) of the EMG signal was analyzed during each variation of push-up exercise for both muscles. Muscle activity was calculated as percentage maximum voluntary isometric contraction (% MVIC).

Results

EMG activity of PM muscle was significantly greater in WSW hand position as compared to SW (p?<?0.01) and NSW (p?<?0.01) hand position; whereas, the activity of TB was significantly greater in NSW hand position as compared to SW (p?<?0.01) and WSW (p?<?0.01) hand position. There were no significant differences in the EMG activity of PM (p?=?0.54) and TB (p?=?0.68) muscles between the push-up bar versus the perfect push-up.

Conclusion

WSW hand position may be used during a push-up when the goal is to strengthen PM; whereas, an NSW hand position may be utilized for the selective strengthening of TB muscle. Both perfect push-up and push-up bar may be utilized by overhead athletes for performing push-ups based on the availability of equipment.

     

Sports ability after Bankart procedure in professional athletes

Recurrent anterior shoulder instability and the restoration of sports ability after surgery are common problems, especially among professional athletes. The purpose of this study was to evaluate the rate, level and time of returning to sports activity after Bankart procedure in anterior shoulder instability in high level atheletes. From 1992–1994 61 patients suffering from recurrent anterior shoulder instability were operated on open Bankart procedure. 44 out of 61 were professional athletes. There were 7 handball, 7 basketball, 6 football, 2 waterpolo and 1 base-ball player and 4 wrestlers, 2 weightlifters, 2 boxers, 3 bicyclists, 2 motorists, 2 swimmers, 2 sailors, 2 kayakers and 2 skiers. The mean duration of instability was 19.1 months (3–72) before operation. 29 patients had posttraumatic recurrent anterior dislocation and 15 patients had posttraumatic anterior subluxations. The average number of redislocations was 4.4, ranging from 2 to 11. At the follow-up examination the patients were tested clinically for instability using the special score created by Walch and Duplay and the Constant functional score. We measured the strength of the rotator cuff by Kintrex isokinetic device from the 10th postoperative week. 35 out of 44 professional athletes could be fellowed-up. The average follow-up period was 14.2 months, from 6 to 31. 88% of the patients were able to return to sports participation, 66% on the previous levels and 22% on a lower level. 12% of the patients finished their professional sports career. The mean rehabilitation period was 5.8 months, the average period of full restoration of sports ability was 9.3 months. Similar results were documented with the Constant score and the Walch-Duplay test (88% excellent or good, 12% fair). The main reason for the inability to continue sports activity was some pain during extreme abduction and extrnal rotation of the arm and recurrent sensations of subluxation (3 cases). Based on the results of the follow-up examinations an early diagnosis is paramount followed by timely surgical intervention to restore anatomical integrity in proven cases of shoulder instability in professional athletes. The open Bankart procedure is preferred giving excellent functional results and providing good chances for the atheletes to return to their previous sports level.     

Proprioception and EMG pattern after capsulolabral reconstruction in shoulder instability: a clinical and experimental study

The anterior capsulolabral reconstruction according to JOBE [13] is a modification of the Bankart operation. The capsular shift is performed via a subscapularis-split approach avoiding any incision into the musculature. A total of 43 patients with posttraumatic, chronic anterior shoulder instability underwent surgery. All patients had at least four dislocations preoperatively. Thirty-five patients were examined after an average of 3.7 ± 1.4 years. Twenty-nine (82.9%) of these patients were free of pain, with functional assessment showing a mean external rotation deficit of 4.1° ± 2.9° without any further movement restrictions. On average, a Rowe-Score of 86.1 ± 12.4 points and an ASES-Score of 93.3 ± 8.4 were achieved. The reluxation rate was 7.7%. The study demonstrated that despite the good clinical results, only 69% of patients were able to return to their previous sports activity level. This special problem is in agreement with other similar studies [4, 18] so that this relevant fact was further addressed by determination of proprioception and electromyographic muscle activity. Postoperatively, in contrast to other studies [1, 21, 24], a persisting proprioceptive deficit as well as an altered EMG pattern was found together with a significant reduction in activity of the deltoideus muscle on the operated side. These results may explain the problem to achieve complete restitution of the function of the shoulder joint after capsulolabral reconstruction.     

Sports activity after arthroscopic superior labral repair using suture anchors in overhead-throwing athletes

PURPOSE: To evaluate the results of arthroscopic repair of type II superior labral anterior posterior lesions of the shoulder in overhead athletes. HYPOTHESIS: Such repair is useful for overhead athletes in terms of postoperative sports activity. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: The study group was composed of 40 patients with a mean age of 24 years (range, 15-38 years); mean follow-up was 41 months (range, 24-58 months). They were divided into an overuse (n=22) and a trauma group (n=18). The authors used 2 suture anchors loaded with a nonabsorbable suture at the 11-o'clock and 1-o'clock positions through the anterosuperior and lateral trans-rotator cuff portal. A modified Rowe score and postoperative athletic activities were evaluated. RESULTS: After arthroscopic repair, mean modified Rowe scores improved from 27.5 to 92.1 points (P<.0001). Rated on this scale, the results were excellent in 30 (75%), good in 6 (15%), and fair in 4 (10%) athletes; there were no poor results. Satisfactory outcomes were achieved in 36 (90%) of these patients; 30 (75%) experienced a return to the preinjury level. The complete return rate of baseball players in the overuse group was lower than that of other overhead athletes in the trauma group. CONCLUSION: Arthroscopic superior labral repair is a safe and reliable procedure in overhead athletes.     

Impingement of the rotator cuff in athletes caused by instability of the shoulder joint

An impingement of the rotator cuff can be caused by chronic anterior instability of the shoulder joint. This particular disease is often found in athletes engaged in overhead motion in abduction/external rotation of the arm, such as in ball sports like volleyball or European handball, racket sports like tennis or badminton, or swimming. For those patients that cannot be cured by conservative treatment such as muscular stabilization, surgical treatment is indicated: anterior reconstruction of the capsule and/or the glenoid labrum, and in addition — if necessary — subacromial decompression and revision of the rotator cuff. Between October 1988 and April 1992, we operated on 66 shoulders in 64 top athletes suffering from chronic anterior or multidirectional instability of the shoulder joint that had caused an impingement syndrome of the rotator cuff. In all cases, the athlete was unaware of the instability. Conservative treatment had been unsuccessful. Surgical treatment was successful in close to 90% of the athletes.     

Evaluation of isokinetic force production and associated muscle activity in the scapular rotators during a protraction-retraction movement in overhead athletes with impingement symptoms

OBJECTIVES: To determine if the muscle force and electromyographic activity in the scapular rotators of overhead athletes with impingement symptoms showed differences between the injured and non-injured sides. METHODS: Isokinetic peak force was evaluated during protraction and retraction of the shoulder girdle, with simultaneous recording of electromyographic activity of the three trapezius muscles and the serratus anterior muscle, in 19 overhead athletes with impingement symptoms. RESULTS: Paired t tests showed significantly lower peak force during isokinetic protraction at high velocity (p<0.05), a significantly lower protraction/retraction ratio (p<0.01), and significantly lower electromyographic activity in the lower trapezius muscle during isokinetic retraction on the injured side than on the non-injured side (p<0.05). CONCLUSION: These results confirm that patients with impingement symptoms show abnormal muscle performance at the scapulothoracic joint.     

Mobility and stability adaptations in the shoulder of the overhead athlete: a theoretical and evidence-based perspective

Overhead athletes require a delicate balance of shoulder mobility and stability in order to meet the functional demands of their respective sport. Altered shoulder mobility has been reported in overhead athletes and is thought to develop secondary to adaptive structural changes to the joint resulting from the extreme physiological demands of overhead activity. Researchers have speculated as to whether these structural adaptations compromise shoulder stability, thus exposing the overhead athlete to shoulder injury. Debate continues as to whether these altered mobility patterns arise from soft-tissue or osseous adaptations within and around the shoulder. Researchers have used quantitative techniques in an attempt to better characterize these structural adaptations in the shoulders of overhead athletes. Throwing athletes have been shown to display altered rotational range of motion (ROM) patterns in the dominant shoulder that favour increased external rotation and limited internal rotation ROM. Throwers also show a loss of horizontal or cross-body adduction in the throwing shoulder when compared with the non-throwing shoulder. This posterior shoulder immobility in the throwing shoulder is thought by some researchers to be associated with reactive scarring or contracture of the periscapular soft-tissue structures (e.g. posterior capsule and/or cuff musculature); however, evidence of reactive scarring or contractures of the posterior-inferior capsule or cuff musculature from anatomic or noninvasive imaging studies is lacking. Conversely, translational ROM (laxity) has been consistently shown to be symmetric between dominant and non-dominant shoulders of overhead athletes.From a skeletal perspective, throwing shoulders are shown to have more humeral retroversion when compared with the non-throwing shoulder. Alterations in humeral retroversion are thought to develop over time in young pre-adolescent throwers when the proximal humeral epiphysis is not yet completely fused. Even though the evidence is inconclusive at the present time, there is more compelling evidence that leads us to believe that altered shoulder mobility in the overhead-throwing athlete is more strongly associated with adaptive changes in proximal humeral anatomy (i.e. retroversion) than to structural changes in the articular and periarticular soft tissue structures. In addition, this retroversion is thought to account for the observed shift in the arc of rotational ROM in overhead athletes. However, in some athletes, capsulo-ligamentous adaptations such as anterior-inferior stretching or posterior-inferior contracture may become superimposed upon the osseous changes. This may ultimately lead to pathological manifestations such as secondary impingement, type II superior labrum from anterior to posterior (SLAP) lesions and/or internal (glenoid) impingement.Overuse injuries in the overhead athlete are a common and perplexing clinical problem in sports medicine and, therefore, it is imperative for sports medicine clinicians to have a thorough understanding of the short- and long-term effects of overhead activity on the shoulder complex. It is our intention that the information presented will serve as a guide for clinicians who treat the shoulders of overhead athletes.     

An in vitro study of glenohumeral performance after suprascapular nerve entrapment

PURPOSE: The functional performance of athletes with suprascapular nerve entrapment remains unaddressed biomechanically. The purpose of this study was to investigate the glenohumeral joint kinematics, stability, and characteristics of joint contact. METHODS: The investigation used an in vitro model simulating muscle palsy due to the suprascapular nerve entrapment. The experiment was performed in three clinically relevant positions: inferior, one by sulcus test; posterior, one with 90 degrees flexion and maximal internal rotation; and anterior, one with 90 degrees abduction and 90 degrees external rotation (which is critically involved in several sports activities). RESULTS: Simulated palsy due to suprascapular nerve entrapment had effects on glenohumeral joint stability and contact characteristics. Changes in the humeral head displacement and the glenohumeral joint contact characteristics were the most significant in the anterior direction when the arm in 90 degrees abduction and 90 degrees external rotation. CONCLUSION: Glenohumeral function is affected by muscle weakness at the position that is critical in sports activities. Because the infraspinatus supplies 90% of the external rotation power of the shoulder and the supraspinatus stabilizes the humeral head in the glenoid during elevation, residual weakness due to suprascapular nerve entrapment may preclude a safe return to athletics.     

Sonographic stress measurement of glenohumeral joint laxity in collegiate swimmers and age-matched controls

BACKGROUND: Glenohumeral laxity that is greater than normal has been implicated as a causal factor in the development of shoulder pain and dysfunction in elite swimmers; however, quantitative evidence demonstrating greater-than-normal glenohumeral joint laxity in swimmers is lacking. OBJECTIVE: To quantify glenohumeral joint laxity in elite swimmers and nonswimming controls using stress sonography. STUDY DESIGN: Controlled laboratory study. METHODS: Force-displacement measures were performed bilaterally in 42 National Collegiate Athletic Association Division I swimmers and 44 age-matched controls. Of the 42 swimmers, 27 (64%) reported a history of unilateral or bilateral shoulder pain resulting from swimming. Ultrasound imaging was used to measure glenohumeral joint displacement under stressed and non-stressed conditions. RESULTS: An analysis of variance revealed no significant difference in glenohumeral joint displacement between swimmers (anterior, 2.82 +/- 1.7 mm; posterior, 5.30 +/- 2.4 mm) and age-matched controls (anterior, 2.74 +/- 1.7 mm; posterior, 4.90 +/- 2.7 mm). No significant difference in glenohumeral joint displacement was found between swimmers with a history of shoulder pain (anterior, 2.90 +/- 1.6 mm; posterior, 5.42 +/- 2.3 mm) versus swimmers without a history of shoulder pain (anterior, 2.74 +/- 1.8 mm; posterior, 5.14 +/- 2.6 mm). Shoulders displayed significantly more glenohumeral joint displacement in the posterior direction compared to the anterior direction (P < .001). CONCLUSIONS: Our instrumented technique was unable to identify significantly greater glenohumeral joint displacement in elite swimmers compared to nonswimming controls, and elite swimmers with a history of shoulder pain were not found to have significantly more glenohumeral joint displacement compared to swimmers without a history of shoulder pain. CLINICAL RELEVANCE: Objective assessment of glenohumeral joint displacement in athletes participating in overhead-motion sports may be important for injury prevention and management.     

Surgical treatment of dislocations of the acromioclavicular joint in the athlete.

The treatment of the sports related dislocation of the acromioclavicular joint remains controversial. This study was carried out to determine whether or not a combined surgical procedure consisting of repair and polydioxanone (PDS)-cord augmentation of the coracoclavicular ligaments, fixation of the acromioclavicular joint with a single Kirschner wire as well as the repair of the acromioclavicular ligament permitted return to athletic activity. Athletes were examined with regard to their range of motion, pain and their ability to return to the performance level achieved before the injury. During the period 1986-1989, 21 athletes were treated. Follow-up averaged 22 months. Return of athletes to previous performance level was related to their original degree of activity. Two recreational once-a-week athletes did not return to this level, 19 patients, including five competitive athletes, continued their previous activities. There was no correlation between coracoclavicular ossification or post-traumatic arthritis and a good or excellent result. We recommend the operative treatment of acromioclavicular separations in athletes.     

Rotator Cuff Impingement Syndrome in Sports

Activities such as pitching, swimming, and serving a tennis ball, which involve overhead movement of the arm, can cause pain around the shoulder. Rotator cuff impingement syndrome is confusing for physicians to diagnose, so the physical examination must be done systematically. Young athletes with the syndrome usually have an insidious onset of soreness in the shoulder that becomes more severe if they continue the offending activity. Treatment revolves around decreasing inflammation, increasing shoulder function, and correcting the cause of the problem. With proper diagnosis and treatment, nonsurgical treatment is successful and allows most patients to return to their previous level of activity.     

Nonoperative management for in-season athletes with anterior shoulder instability

BACKGROUND: Acute or recurrent anterior shoulder instability is a frequent injury for in-season athletes. Treatment options for this injury include shoulder immobilization, rehabilitation, and shoulder stabilization surgery. PURPOSE: To determine if in-season athletes can be returned to their sports quickly and effectively after nonoperative treatment for an anterior instability episode. METHODS: Over a 2-year period, 30 athletes matched the inclusion criteria for this study. Nineteen athletes had experienced anterior dislocations, and 11 had experienced subluxations. All were treated with physical therapy and fitted, if appropriate, with a brace. These athletes were followed for the number of recurrent instability episodes, additional injuries, subjective ability to compete, and ability to complete their season or seasons of choice. RESULTS: Twenty-six of 30 athletes were able to return to their sports for the complete season at an average time missed of 10.2 days (range, 0-30 years). Ten athletes suffered sport-related recurrent instability episodes (range, 0-8 years). An average of 1.4 recurrent instability episodes per season per athlete occurred. There were no further injuries attributable to the shoulder instability. Sixteen athletes underwent surgical stabilization for their shoulders during the subsequent off-season. CONCLUSIONS: Most of the athletes were able to return to their sport and complete their seasons after an episode of anterior shoulder instability, although 37% experienced at least 1 additional episode of instability during the season.     

Arterial abnormalities of the shoulder in athletes

Vascular lesions of the shoulder may be misinterpreted as one of the more familiar shoulder abnormalities by a treating physician. We are reporting on 13 athletes who were found to have symptoms related to compression of the subclavian or axillary artery or their tributaries. Nine were amateur or professional baseball pitchers. Severe arm fatigue or finger ischemia, secondary to embolization, were presenting symptoms. Arm fatigue was noted in all pitchers. After complete history and physical examination, including auscultation for bruits in functional positions, all athletes were evaluated by noninvasive tests (Doppler and Duplex scanning). Arteriography was performed with positional testing, recreating overhead activity, and complete radiographic visualization of the dye to the digital arteries. Two patients were found to have subclavian artery aneurysm. The remaining athletes were found to have compression of the subclavian artery beneath the anterior scalene muscle (five patients), the axillary artery beneath the pectoralis minor (two patients), both arterial segments (two patients), and one was found to have arterial compromise at the level of the humeral head. Branch artery compression was also noted. One pitcher occluded the posterior circumflex humeral artery with embolization to the digit. The two patients with subclavian aneurysms underwent saphenous vein bypass with cervical rib resection. All of the other athletes except one underwent resection of a 2 to 3 cm segment of the anterior scalene muscle or pectoralis minor muscles. All returned to their previous level of activity except one patient who developed impingement type symptoms and required acromioplasty. He is currently undergoing rehabilitation. Proper recognition of vascular compromise in the upper extremity of athletes is essential to avoid the catastropic complications of arterial thrombosis.     

Muscular imbalance and shoulder pain in volleyball attackers.

OBJECTIVE: In overhead sports such as volleyball, baseball, or tennis shoulder problems are very common. The aim of this study was to identify features which may correlate with shoulder problems in volleyball attackers. METHODS: 30 competitive volleyball attackers (mean age 25 years) were included in the study; 15 were suffering from shoulder pain and 15 had no history of shoulder pain. The results were compared with those of a control group of 15 recreational athletes without any overhead sports activities. RESULTS: Volleyball attackers have a different muscular and capsular pattern at the playing shoulder compared to the opposite shoulder. Their playing shoulder is depressed, the scapula lateralised, and the dorsal muscles and the posterior and inferior part of the shoulder capsule shortened. These differences were of more significance in volleyball attackers with shoulder pain than in volleyball players without shoulder pain. In contrast to recreational athletes without any overhead sports activity, there were no significant difference in the comparison of the two shoulders. The histories, clinical and sonographic findings did not reveal further typical features for volleyball attackers with shoulder pain. CONCLUSIONS: Muscular balance of the shoulder girdle is very important in this sport. It is therefore imperative to include adequate stretching and muscular training programme for the prevention, as well as for therapy, of shoulder pain in volleyball attackers.     

Suprascapular nerve entrapment at the spinoglenoid notch in a professional baseball pitcher

Suprascapular nerve injuries at the spinoglenoid notch are uncommon. The true incidence of this lesion is unknown; however, it appears to be more common in athletes who participate in sports involving overhead activities. When a patient is being evaluated for posterior shoulder pain and infraspinatus muscle weakness, electrodiagnostic studies are an essential part of the evaluation. Electromyography will identify an injury to the suprascapular nerve as well as assist in localizing the site of injury. In addition, imaging studies are also indicated to help exclude other diagnoses that can mimic a suprascapular nerve injury. The initial management should consist of cessation of the aggravating activity along with an organized shoulder rehabilitation program. If the patient fails to improve with 6 months to 1 year of nonoperative management, surgical exploration of the suprascapular nerve should be considered. Release of the spinoglenoid ligament with resultant suprascapular nerve decompression may result in relief of pain and a return of normal shoulder function.     

Closed kinetic chain alone compared to combined open and closed kinetic chain exercises for quadriceps strengthening after anterior cruciate ligament reconstruction with respect to return to sports: a prospective matched follow-up study

Rehabilitation after anterior cruciate ligament (ACL) reconstruction has focused over the past decade on closed kinetic chain (CKC) exercises due to presumably less strain on the graft than with isokinetic open kinetic chain exercises (OKC); however, recent reports suggest that there are only minor differences in ACL strain values between some CKC and OKC exercises. We studied anterior knee laxity, thigh muscle torque, and return to preinjury sports level in 44 patients with unilateral ACL; group 1 carried out quadriceps strengthening only with CKC while group 2 trained with CKC plus OKC exercises starting from week 6 after surgery. Anterior knee laxity was determined with a KT-1000 arthrometer; isokinetic concentric and eccentric quadriceps and hamstring muscle torque were studied with a Kin-Com dynamometer before and 6 months after surgery. At an average of 31 months after surgery the patients answered a questionnaire regarding their current knee function and physical activity/sports to determine the extent and timing of their recovery. No significant differences in anterior knee laxity were noted between the groups 6 months postsurgery. Patients in group 2 increased their quadriceps torque significantly more than those in group 1, but no differences were found in hamstring torque between the groups. A significantly higher number of patients in group 2 (n=12) than in group 1 (n=5) returned to sports at the same level as before the injury (P<0.05). Patients from group 2 who returned to sports at the same level did so 2 months earlier than those in group 1. Thus the addition of OKC quadriceps training after ACL reconstruction results in a significantly better improvement in quadriceps torque without reducing knee joint stability at 6 months and also leads to a significantly higher number of athletes returning to their previous activity earlier and at the same level as before injury.     

Electromyographic analysis in patients with multidirectional shoulder instability during pull,forward punch,elevation and overhead throw

Multidirectional shoulder joint instability alters the role of dynamic stabilizers, as a result of which the motion patterns of the muscle around the shoulder joint are also changed. The aim of this study was to compare the muscle activity of patients with multidirectional shoulder instability and the control group during pull, forward punch, elevation and overhead throw. Fifteen subjects with multidirectional shoulder instability and fifteen control subjects with normal, healthy shoulders participated in the study. Both shoulders were tested in all subjects. Signals were recorded by surface EMG from eight different muscles during pull, forward punch, elevation and overhead throw. The mean and standard deviation of MVE% for the different movement types and time broadness values during overhead throw were determined for each muscle in both groups and compared with each other. Test results suggest that in case of patients with multidirectional shoulder instability the various motions are performed in a different way. The results give rise to the assumption that the centralization of the glenohumeral joint and the reduction of instability are attempted to be ensured by the organism through increasing the role of rotator cuff muscles and decreasing the role of the deltoid, biceps brachii and pectoralis maior muscles. The analysis of time broadness shows that in patients with multidirectional shoulder instability, the time difference between the peaks of normalized voluntary electrical activity is significantly greater than in the control group.