Physiological characteristics of top level off-road motorcyclists.

OBJECTIVES: The study aims to analyse the physiological characteristics of top level off-road motocross, enduro, and desert rally motorcyclists to facilitate the design of a specific training program. METHODS: Twenty seven off-road top level riders participated in this study which measured anthropometric data, maximum aerobic power with incremental tests of both arms and legs, isokinetic dynamometry of the knee and elbow, handgrip strength, heart rate, and blood lactate concentrations during competition. RESULTS: The physical demands of the various races appear to influence the development of distinct musculoskeletal characteristics, as well as aerobic and anaerobic metabolism. Motocross riders have more muscle mass, higher isokinetic handgrip strength, and greater aerobic power than enduro and desert rally riders. However, there are no significant anthropometric and physiological differences between desert rally and enduro riders. Desert rally riders tend to be overweight with maximum aerobic power similar to that of healthy individuals. The mechanical characteristics of the motorcycle and the technical and tactical skills of the riders seem to be more important for race success than the metabolic capabilities of the rider. CONCLUSIONS: Desert rally and enduro riders present similar anthropometric and physiological characteristics. Both have a maximum aerobic power similar to that of healthy normal individuals, although desert rally riders tend to be overweight. Motocross riders on the other hand, have more muscle mass, more strength, and greater aerobic power. The differences observed suggest the need for a specific training program to address the requirements of different riders to reduce the possibility of injury.

Infraspinatus muscle-splitting incision in posterior shoulder surgery. An anatomic and electromyographic study.

Standard posterior shoulder surgical approaches include infraspinatus tendon detachment and infraspinatus-teres minor interval development. Cadaveric and clinical investigation of a new infraspinatus-splitting approach to the posterior glenohumeral joint was undertaken to assess efficacy in providing exposure, preserving tendon attachment, and avoiding neurologic compromise. Infraspinatus musculotendinous and neural anatomy was examined in 20 cadavers. Four patients with posterior shoulder instability underwent posterior capsulorrhaphy through this infraspinatus-splitting approach, followed by electrodiagnostic testing. Infraspinatus muscle was bipennate in all specimens, the tendinous interval an average 14 mm inferior to the scapular spine at the glenoid rim. The infraspinatus-splitting interval bisected the posterior glenoid rim at its midpoint, whereas the infraspinatusteres minor interval crossed the glenoid rim's lower quarter. The suprascapular nerve provided sole innervation to the infraspinatus muscle in all specimens, entering the infraspinous fossa at the notch as a single trunk 22 mm medial to the glenoid rim. Minimum branching variability was observed. Electrodiagnostic testing showed no evidence of axonal damage or muscle denervation in either infraspinatus pennate bundle. Limiting infraspinatus-splitting dissection medially to 1.5 cm from the posterior glenoid rim prevents damage to any interval-crossing suprascapular nerve branches. Posterior shoulder surgery through a horizontal, longitudinal infraspinatus tendon-splitting approach provides excellent exposure of posterior capsule, labrum, and glenoid, without requiring tendon detachment or causing neurologic compromise.

Anterior capsulolabral reconstruction of the shoulder in athletes in overhand sports.

From April 1, 1985, through June 30, 1987, 25 skilled athletes with shoulder pain secondary to anterior glenohumeral instability that had failed to improve with conservative therapy had an anterior capsulolabral reconstruction. All but one athlete completed a formal rehabilitation program with an average followup of 39 months. The results at followup were rated excellent in 68%, good in 24%, fair in 4%, and poor in 4%. Seventeen patients returned to their prior competitive level for at least 1 year. This operation and rehabilitation program may allow many athletes who participate in overhand activities or throwing sports to return to their prior level of competition.

The value of weighted views of the acromioclavicular joint. Results of a survey.

One hundred twelve practicing members of the American Shoulder and Elbow Surgeons in the United States and Canada were surveyed regarding use of weighted views of the acromioclavicular joint. They were also asked about treatment for hypothetical patients seen in the emergency department or office with grade II or III acromioclavicular separations. One hundred five physicians (94%) responded to the survey. Eighty-five members (81 %) did not recommend obtaining weighted views in the emergency department. Sixty members (57%) did not use weighted views, and the majority commented that weighted views had no influence on their decision-making regarding treatment. Forty-five members (43%) used weighted views, but most did not use the results of this test to determine surgical intervention. Physicians recommending weighted views averaged 21 years of practice, compared with 16 years for those who did not obtain weighted views. Only nine physicians (9%) had changed treatment on the basis of weighted views. The patient's arm dominance, work, or athletic status did not influence most surgeons' decision to perform surgery when weighted views revealed a grade III separation. We found no correlation between obtaining weighted views and performing surgical reconstruction for patients with grade III acromioclavicular separations.

Arthroscopy of the elbow: a long-term clinical review.

PURPOSE: The purpose of this study was to review a large group of patients who had arthroscopy of the elbow to determine the efficacy and relative risks of this procedure. TYPE OF STUDY: We retrospectively reviewed a convenient sample of 172 patients who underwent 187 arthroscopies of the elbow over a 7-year period. MATERIALS AND METHODS: All patients had their charts and radiographs reviewed, and 104 of these patients were also contacted for a telephone interview at an average follow-up of 42.3 months (range, 7 to 115 months). RESULTS: The procedures were performed primarily by 7 different surgeons, using all 3 standard operating positions and a variety of arthroscopic portals. The most common diagnosis was posterior impingement in 96 patients (51%), followed by loose bodies in 72 patients (31%), and degenerative joint disease in 32 patients (22%). The average preoperative modified Figgie score was 27.7 points (range, 17-43) for all patients. The average postoperative score was 45.4 points (range, 29-50), with the largest increase occurring in the pain score. There were 51 patients (56%) with an excellent surgical result, 37 patients (36%) with a good result, 12 patients (11%) with a fair result, and 4 patients (4%) with a poor result. The average modified Figgie score increased from 31.2 points (range, 22-43) to 46.9 (range, 29-50) postoperatively in professional athletes; from 26.3 to 42.6 in patients who had Workers' Compensation claims but were not professional athletes; from 29.4 to 45.6 in patients with a diagnosis of loose bodies; and from 30.1 to 43.7 in patients with degenerative joint disease. There were 3 known surgical complications (1.6%) overall, 1 of which was a patient who had a transection of the ulnar nerve requiring microsurgical repair. Of the 104 patients who were contacted, 6 patients felt that their symptoms had not improved after surgery. Eight of the 55 baseball players contacted were not able to return to their same level of competition. CONCLUSIONS: Arthroscopy of the elbow appears to be a safe and efficacious procedure with a relatively low complication rate.

Shoulder instability in the overhand or throwing athlete.

In the young throwing athlete with shoulder pain, it is essential to recognize that glenohumeral joint instability (occult subluxation, rather than impingement) is the primary underlying pathology. Fortunately, conservative management is effective in most chronic overuse injuries. For those athletes with continued symptoms, surgical intervention may become necessary. The anterior capsulolabral reconstruction addresses the problem of glenohumeral joint instability by correcting the capsular redundancy, labrum damage, or both. The authors believe this most recent surgical technique and postoperative rehabilitation program has resulted in a significant improvement in our ability to more predictably and successfully return these athletes to prior competitive levels.

The diagnosis and treatment of anterior instability in the throwing athlete.

In the overhand or throwing athlete, the shoulder is extremely vulnerable to injury due to the repetitive, high-energy forces. When these stresses are applied at a rate that exceeds that of tissue repair, progressive damage to the shoulder's stabilizing structures can occur. With continued throwing, the static restraints become progressively attenuated, allowing anterior glenohumeral subluxation. Initially, the dynamic stabilizers can compensate for this mild instability with increased muscle activity. Prolonged activity, however, may lead to fatigue. Over time, these compensatory mechanisms can become overloaded. The humeral head then may subluxate anteriorly, where it contacts with the coracoacromial arch, ultimately leading to subacromial impingement. Posterosuperior glenoid impingement may also occur as anterior humeral translation allows the undersurface of the tendinous portions of the supraspinatus and infraspinatus to impinge along the posterosuperior border of the glenoid rim. Fortunately, conservative management is effective in most chronic overuse injuries and includes an initial period of relative rest (avoidance of throwing), oral nonsteroidal antiinflammatory medication, a physical therapy program structured to provide local modalities to reduce inflammation, and a strengthening program for the rotator cuff and scapular rotators. For those athletes with continued symptoms, surgical intervention may become necessary. The appropriate surgical treatment depends on the diagnosis. In the young throwing athlete with shoulder pain, it is essential to recognize that instability or occult subluxation, rather than impingement, is the primary underlying pathology. The anterior capsulolabral reconstruction addresses the problem of instability by correcting the capsular redundancy or labral damage or both. When performed in the manner described, muscle attachments and proprioceptive muscle fibers are not disturbed and full shoulder range of motion can quickly be achieved. This most recent surgical technique and postoperative rehabilitation program has resulted in a significant improvement in the ability to correct instability in those athletes who have failed a prolonged course of conservative care. Prevention of these injuries may be attained, it is hoped, through continued research into the basic biomechanics and the pathoanatomy associated with overhand sports.(ABSTRACT TRUNCATED AT 400 WORDS)

Shoulder pain in the overhand or throwing athlete. The relationship of anterior instability and rotator cuff impingement.

Shoulder pain in the overhand or throwing athlete can often be traced to the stabilizing mechanisms of the glenohumeral joint. During the physical examination, signs of impingement will often be obvious, whereas subluxation signs are subtle. Use of the Apprehension Test followed by the Relocation Test has proved to be the most sensitive means of detecting occult anterior glenohumeral subluxation. When subluxation is suspected, an examination under anesthesia and orthroscopy are the most helpful next step. Patients can be classified into one of four groups on the basis of the results of the examinations. If conservative rehabilitation fails, then surgery may be considered.

Electromyographic investigation of stretching: the effect of warm-up.

OBJECTIVE: To compare the fine wire electromyographic (EMG) firing patterns during static stretches in the biceps femoris, soleus, and gastrocnemius before and after warm-up as well as over time. DESIGN: Experimental single group pretest-posttest design. SETTING: Biomechanics research laboratory. PARTICIPANTS: Sixteen healthy volunteers 23 to 36 years of age with no history of lower extremity injury. INTERVENTION: Subjects performed one hamstring stretch and four calf stretches for 90 seconds, bicycled for 30 minutes as a warm-up, and stretched again. MAIN OUTCOME MEASURE: EMG was recorded at time 0, 30, 60, and 90 seconds during the stretches before and after warm-up. Recorded values were normalized to EMG during maximum manual muscle testing (MMT). A two-way analysis of variance with repeated measures (p < 0.05) was done to compare EMG activity during stretching before and after warm-up as well as over time. RESULTS: Low EMG activity was seen for all muscles (< 20% MMT). It was constant over the time of the stretch for all muscles, but it increased in the soleus during the bent knee stretch position. There was a statistically significant decrease in the EMG activity after the warm-up for the gastrocnemius using the traditional and heel off stretching positions and for the soleus using the heel off stretching position (p < 0.05). The biceps femoris EMG activity showed no significant differences before and after warm-up. CONCLUSIONS: EMG activity during static stretching was low. Overall, the EMG activity remained constant with time for a given stretch position. EMG of the soleus and gastrocnemius was significantly less after warm-up for some stretches, whereas the EMG activity of biceps femoris showed no differences before and after warm-up.

Anterior capsulolabral reconstruction of the shoulder in athletes.

We did an anterior capsulolabral reconstruction for recurrent subluxation or dislocation of the shoulder in 75 athletes after failure of conservative therapy. Average follow-up was 39 months (range 28 to 60 months). The results were 77% excellent, 75% good, 3% fair, and 5% poor. Seventy-five percent of the professional and 100% of the college baseball players returned to their previous level of competition. Seventy-seven percent of the professional pitchers were able to return to professional pitching. The range of motion at follow-up was full in 79% of the athletes. No infections or nerve injuries occurred. The anterior capsulolabral reconstruction procedure combined with an early rehabilitation program appears to provide an improved outcome compared with previously reported procedures for anterior instability of the shoulder in athletes.

Arthroscopic findings in the overhand throwing athlete: evidence for posterior internal impingement of the rotator cuff.

SUMMARY: The purpose of this article is to describe the outcome of an arthroscopic examination and the pathology in symptomatic shoulders of 41 professional overhand throwing athletes. With the arm in the position of the relocation test, 100% of the subjects had either contact between the rotator cuff undersurface and the posterosuperior glenoid rim or osteochondral lesions. Other key findings included undersurface cuff fraying in 93%, posterosuperior labral fraying in 88%, and anterior labral fraying in 36% of the subjects. This study supports the concept of impingement of the posterior cuff undersurface with the posterosuperior glenoid rim in the overhand throwing athlete with shoulder pain.