Trapezius activity and intramuscular balance during isokinetic exercise in overhead athletes with impingement symptoms

We compared normalized trapezius muscle activity and intramuscular balance ratios between overhead athletes with impingement symptoms and non-injured athletes during isokinetic abduction and external rotation movements. Thirty-nine overhead athletes with chronic impingement symptoms and 30 non-injured athletes participated in the study. Electromyographic activity of upper, middle, and lower trapezius was measured during isokinetic abduction and external rotation, using surface electrodes. The results show a significant increase of upper trapezius activity during both movements in the patient group, with decreased activity in the lower trapezius during abduction, and in the middle trapezius during external rotation. Analysis of the intramuscular activity ratios revealed muscle imbalance on the injured side of the patient group for upper/middle trapezius and upper/lower trapezius during abduction, and for all three muscle activity ratios during external rotation. These results confirm the presence of scapular muscle imbalances in patients with impingement symptoms and emphasize the relevance of restoration of scapular muscle balance in shoulder rehabilitation.     

Shoulder MR arthrography of the posterior labrocapsular complex in overhead throwers with pathologic internal impingement and internal rotation deficit

Purpose To determine if overhead-throwing athletes with internal impingement pain and internal rotation deficit have thickening of the posterior inferior labrocapsular complex on MR arthrogram images. Materials and methods This study was approved and a waiver of consent granted by our institutional review board. Twenty-six overhead-throwing athletes with internal impingement pain and internal rotation deficit, and 26 controls who had undergone MR arthrograms, were retrospectively examined. The MR studies were combined and read in a blind fashion. On an axial image through the posteroinferior glenoid rim, the readers measured the labral length, capsule-labrum length, and the posterior recess angle. A t-test was used to determine statistical significance. Results The mean labral length was 4.9 mm [standard deviation (SD) 1.4 mm] for the controls, and 6.4 mm (SD 1.6 mm) for the athletes (P = 0.001). The mean capsule-labrum length was 5.4 mm (SD 2.1 mm) for the controls, and 8.8 mm (SD 2.9 mm) for the athletes (P < 0.001). The mean posterior recess angle measured 65° (SD 27°) for the controls and 94° (SD 38°) for the athletes (P = 0.002). Conclusions Overhead-throwing athletes with internal impingement pain and internal rotation deficit tend to have a thicker labrum and a shallower capsular recess in the posterior inferior shoulder joint than do non-overhead-throwing athletes. In many, the posteroinferior capsule is also thickened. These MR findings should alert the radiologist to closely inspect the posterior cuff and posterosuperior labrum for the tears associated with internal impingement.     

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.     

Shoulder injuries in overhead athletes. The "dead arm" revisited

The following statements summarize this article: Three distinct categories of Type 2 SLAP lesions exist: (1) anterior, (2) posterior, and (3) combined anteroposterior. Posterior Type 2 SLAP lesions have distinct clinical and anatomic features that distinguish them from anterior Type 2 SLAP lesions. Posterior and combined Type 2 SLAP lesions can be disabling to overhead-throwing athletes because of posterosuperior instability and anteroinferior pseudolaxity. The Jobe relocation test is positive with posterosuperior pain in patients with posterior or combined anterior-posterior Type 2 SLAP lesions and is negative in patients with anterior Type 2 SLAP lesions. Rotator cuff tears are frequently associated with posterior or combined anterior-posterior SLAP lesions, are lesion-location specific, and typically begin from inside the joint as undersurface tears. Repair of posterior SLAP lesions can return overhead-throwing athletes to full overhead athletic functioning. The peel-back mechanism is a likely cause of posterior Type 2 SLAP lesions. To securely repair the posterosuperior labrum to resist torsional peel-back, sulure anchors must be placed posterior to the biceps at the corner of the glenoid. The repair must be protected against external rotation past 0 degree for 3 weeks to avoid undue premature torsional stresses on the repair from the peel-back mechanism. A tight posteroinferior capsule predisposes to Type 2 SLAP lesions in overhead athletes. Shoulders at risk for the dead arm syndrome have a marked loss of internal rotation caused by contracture of the posteroinferior capsule such that less than a 180 degrees arc of rotation is achieved with the arm abducted 90 degrees (the 180 degrees rule). Type 2 SLAP lesions that cause the dead arm syndrome in overhead-throwing athletes are most likely acceleration injuries that occur in late cocking rather than deceleration injuries in follow-through. Rehabilitation of athletes with the dead arm syndrome must include the entire kinetic chain. The root cause of the dead arm syndrome is the Type 2 SLAP lesion.     

Scapular muscle recruitment patterns: trapezius muscle latency with and without impingement symptoms

BACKGROUND: Altered muscle activity in the scapular muscles is commonly believed to be a factor contributing to shoulder impingement syndrome. However, one important measure of the muscular coordination in the scapular muscles, the timing of the temporal recruitment pattern, is undetermined. PURPOSE: To evaluate the timing of trapezius muscle activity in response to an unexpected arm movement in athletes with impingement and in normal control subjects. STUDY DESIGN: Prospective cohort study. METHODS: Muscle latency times were measured in all three parts of the trapezius muscle and in the middle deltoid muscle of 39 "overhand athletes" with shoulder impingement and compared with that of 30 overhand athletes with no impingement during a sudden downward falling movement of the arm. RESULTS: There were significant differences in the relative muscle latency times between the impingement and the control group subjects. Those with impingement showed a delay in muscle activation of the middle and lower trapezius muscle. CONCLUSION: The results of this study indicate that overhand athletes with impingement symptoms show abnormal muscle recruitment timing in the trapezius muscle. The findings support the theory that impingement of the shoulder may be related to delayed onset of contraction in the middle and lower parts of the trapezius muscle.     

Scapular positioning in overhead athletes with and without shoulder pain: a case–control study

Abnormalities of scapular positioning are considered important risk factors for developing shoulder disorders. This study analyses the scapular positioning pattern in a group of overhead athletes with and without shoulder pain. In a multi‐center blinded case–control study, 36 shoulder pain athletes (19 men, 17 women), were compared with 36 unimpaired athletes free of shoulder pain, matched for gender, age, hand dominance and body mass index. The blinded assessor performed visual observation, the measurement of the distance between the acromion and the table, inclinometry and the kinetic medial rotation test for dynamic scapular control in random order. Athletes with shoulder pain demonstrate scapular asymmetry in the sagittal plane, observed visually as anterior tilting on the painful side. Athletes with shoulder pain show a lack of scapular motor control on their painful side in contrast to their pain‐free side. No scapular positioning or motor control differences were found in athletes with or without shoulder pain.     

Acromioclavicular joint injuries and treatment in overhead athletes

Acromioclavicular (AC) joint symptoms are common in athletes. In particular, overhead athletes place especially high demands on their shoulders. Despite this, these individuals infrequently have isolated AC joint pathology. Understanding the common pathology and associated injuries is important for a safe and quick return to competition.     

Supraspinatus tendon US morphology in basketball players: correlation with main pathologic models of secondary impingement syndrome in young overhead athletes. Preliminary report

PURPOSE: The purpose of this study was to investigate supraspinatus tendon sonographic morphology in a population of young overhead athletes in correlation with main pathologic models of secondary shoulder impingement syndrome. SUBJECTS AND METHODS: Between April and May 2004, 20 subjects (ten professional basketball players and ten non-athlete controls of the same age, weight and height ranges) underwent bilateral, standardised, sonographic sholulder examination to evaluate supraspinatus echotexture, supraspinatus and subacromial bursa thickness, subacromial space width (cutoff of 7 mm) and dynamic anterior impingement beneath the acromial margin. RESULTS: All subjects were right handed. No symptomatic controls were found. Four players showed signs and symptoms of right atraumatic shoulder instability (two cases) or supraspinatus impingement with anterior pain (one right and one left shoulder). Subacromial space width was reduced in five right-dominant players' shoulders (three symptomatic and two asymptomatic) versus zero controls (p<0.05) and in eight players' shoulders versus zero controls on total shoulders (p<0.05). No other significant differences were observed between the two groups in sonographic parameters considered. CONCLUSIONS: Despite the study limitations, ultrasonography (US) is able to detect subacromial space narrowing in young overhead athletes as early shoulder impingement sign, according to the continuum impingement-instability pathologic model.     

Isokinetic performance at diagonal pattern and shoulder mobility in elite overhead athletes

The purpose of this study was to measure isokinetically glenohumeral joint movement peak torque and work in professional basketball, volleyball, handball and baseball players and determine whether significant differences exist between the dominant and non-dominant extremity in athletes and controls. Eighty healthy professional overhead athletes (basketball, volleyball, handball and baseball players) and 20 controls were tested bilaterally on a CYBEX 6000 isokinetic dynamometer at 60 degrees and 180 degrees s(-1) for diagonal pattern of the glenohumeral joint. A standardized protocol and testing guidelines were strictly followed. The range of motion of internal rotation (IR) on the dominant side of baseball players was significantly smaller than those on the dominant side of basketball, handball and volleyball players, and controls (P<0.01). Flexion/abduction/external rotation were consistently higher on the dominant arm (8.5%) for peak torque at 60 degrees s(-1) in baseball players, and bilateral ratios were lower on the dominant arm (14.8%) for peak torque at 180 degrees s(-1) in basketball players. The results of this study are important for the application and interpretation of isokinetic data and flexibility and mobility characteristics on unilaterally dominant overhead athletes. Functional weakness in external rotators, mobility impairments in IR and muscle imbalance have been shown in the dominant arm of these overhead athletes.     

Scapular rotation in swimmers with and without impingement syndrome: practice effects

PURPOSE: The purpose of this study was to examine the effects of a normal swim practice on the scapular kinematics of swimmers with impingement syndrome and healthy swimmers. METHODS: Twenty swimmers with no known shoulder pathology and 20 swimmers with shoulder impingement syndrome participated in this study. Shoulder strength measurements were made with a hand-held dynamometer. Static scapular upward rotation was measured with an inclinometer with the arm at rest, and at 45, 90, and 135 degrees of humeral elevation. Measurements were made pre- and postswim training. RESULTS: There were no differences in baseline measurements of kinematics between the two groups. After swimming, both groups experienced muscle fatigue as indicated by a significant reduction in force generation. Although swimming practice resulted in no significant differences in scapular kinematics for the healthy swimmers, there were significant decreases in scapular upward rotation in subjects with shoulder impingement. CONCLUSIONS: Abnormal scapular kinematics in swimmers with impingement syndrome may only be observed after an intense swim practice. The examination of swimmers immediately after swimming may provide more information regarding impingement syndrome than a typical clinical exam.     

Coracoid impingement syndrome, rotator interval reconstruction, and biceps tenodesis in the overhead athlete

Anterior shoulder problems are extremely common in throwing athletes. Coracoid impingement syndrome, lesions of the long head of the biceps tendon, and rotator interval lesions are included in the extensive differential diagnosis which exists for anterior shoulder pain. In this chapter, we focus on the anatomy, pathophysiology, clinical presentation, diagnosis, and surgical treatment of these conditions.     

Patellar tendon morphology in volleyball athletes with and without patellar tendinopathy

Appropriate management of patellar tendinopathy requires distinguishing between inflammatory and degenerative conditions, often difficult because tendon thickening can be a normal or pathological adaptation, and micromorphology is not observable on clinical imaging. The purpose of this study was to quantitatively examine patellar tendon micro‐ and macromorphology in volleyball athletes and relate those findings to reported symptoms. Longitudinal ultrasound images of proximal and distal patellar tendons were acquired from 84 male elite volleyball athletes (44 symptomatic, 40 asymptomatic) and 10 asymptomatic nonathlete controls. Micromorphology was determined using two‐dimensional Fast Fourier Transform analysis providing a discriminating peak spatial frequency parameter (PSF). Macromorphology (patellar tendon thickness) was measured using Image J software. All athletes regardless of symptoms had thicker proximal tendons compared to nonathletes, suggesting a normal adaptation to training loads. However, symptomatic athletes demonstrated lower PSF than asymptomatic athletes and nonathletes at the proximal tendon, suggesting greater collagen disorganization, and tendon degeneration rather than inflammation. Only symptomatic athletes had thicker distal tendons than nonathletes, but there was no difference in PSF distally. Diagnostic ultrasound enhances the understanding of the micromorphology of patellar tendons, supporting the rationale for management that remodels the degenerated tendon instead of treating inflammation.     

Energy balance in weight stable athletes with and without menstrual disorders

The energy balance and nutritional adequacy was assessed in a group of runners with irregular menstrual function (IR, n = 10) and in a comparable group of runners with normal menstrual function (R, n = 10). Based on computerized records of 3 days food intake, the mean content of energy and macronutrients were estimated. Excess energy expenditure (EEE) during training hours was estimated using HF monitoring and individual HF/VO2 nomograms. For the rest of a daily 24 h cycle, estimated values for basal metabolic rate (BMR) and sedentary metabolic rate were applied. Daily training-related excess energy expenditure (2.1 +/- 0.3 vs 2.2 +/- 0.4) MJ (Mean +/- SEM) and total energy expenditure (TEE) (11.0 +/- 0.3 vs 11.2 +/- 0.4) MJ in R vs IR were not different in the two groups. Calculated daily energy intake (EI) was, however, significantly lower in IR (9.7 +/- 0.5 MJ) than in R (12.3 +/- 0.7 MJ), (P = 0.007). Calculated EI and TEE were in balance in R athletes. When the same calculations were applied on IR athletes, a moderate but statistically significant negative energy balance was found (-1.5 +/- 0.6 MJ, P = 0.03). The calculated energy deficit was supported by significantly lower levels of free thyroxine in IR athletes, and may indicate an adaptive lower BMR in IR athletes. Mean intakes of carbohydrates (7.0 g/kg in R and 5.7 g/kg in IR) and protein (1.71 g/kg in R and 1.49 g/kg in IR) were close to guidelines. Intakes were not significantly different in the two groups. The most important difference in macronutrient intake was found in dietary fat (1.70 g/kg in R and 1.04 g/kg in IR) that was significantly lower in the IR group than in the R group (P = 0.007). The weight stable IR and R athletes seemed to meet the recommended intake of carbohydrates, protein and fat in their diet fairly well. However, according to the present calculations, a small energy deficit was observed in IR athletes but not in R athletes. Compared with the intake of the R athletes, this energy deficit seems primarily to be related to a lower intake of dietary fat in IR athletes.     

Lower limb strength and flexibility in athletes with and without patellar tendinopathy

ObjectivesTo compare the hip, knee and ankle torques, as well as knee and ankle flexibility between athletes with patellar tendinopathy and asymptomatic controls.DesignCross-sectional study.SettingLaboratory setting.ParticipantsFourteen male volleyball, basketball or handball athletes, divided into 2 groups, patellar tendinopathy group (TG; n = 7) and asymptomatic control group (CG; n = 7).Main outcome measuresHip, knee and ankle isometric torques were measured with a handheld dynamometer. Weight-bearing ankle dorsiflexion, hamstring and quadriceps flexibility were measured with a gravity inclinometer.ResultsThe TG had 27% lower hip extensor torque when compared to the CG (P = 0.031), with no group differences in knee and ankle torques (P > 0.05). Also, the TG had smaller weight-bearing ankle dorsiflexion (P = 0.038) and hamstring flexibility (P = 0.006) when compared to the CG. Regarding quadriceps flexibility, no group differences were found (P = 0.828).ConclusionsStrength and flexibility deficits might contribute to a greater overload on the knee extensor mechanism, possibly contributing to the origin/perpetuation of patellar tendinopathy. Interventions aiming at increasing hip extensors strength as well as ankle and knee flexibility might be important for the rehabilitation of athletes with patellar tendinopathy.     

浅议四川人的“外湿内燥”与西北人的“外燥内湿”

地理环境和气象物产的差异直接影响了人们的饮食,由此造成不同的体质变化。干燥的西北地区和位于西南高湿环境中的四川具有截然不同的地域及气候条件,笔者从气候、地域、饮食以及病因病机等多角度比较了四川人与西北人的不同,提出西北地区多＂外燥内湿＂,四川地区多＂外湿内燥＂及＂燥湿同病＂的观点,为部队官兵更好的适应驻地环境,做好卫勤保障工作提供理论依据。