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At least 973 records · Page 54Linked to original sources

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.

Adolescent↗

Loose body in the wrist: diagnosis and treatment.

PURPOSE: The purpose of this study was to report on 10 cases of symptomatic loose bodies in the wrist joints diagnosed using arthroscopy. TYPE OF STUDY: Retrospective review. METHODS: From 1986 to 2000, we performed wrist arthroscopy for 707 patients, 10 of whom had loose bodies in the wrist joints. The clinical records were reviewed retrospectively. The patients included 8 men and 2 women, and the average age was 28 years (range, 16 to 67 years). The chief complaint was wrist pain in all patients, but locking was uncommon. Preoperative diagnosis was difficult in all but 3 cases; in those cases, an osseous component was found within the loose bodies. The remaining cases were diagnosed by wrist arthroscopy. RESULTS: The loose bodies existed in the radiocarpal joint in 5 cases, and all could be removed arthroscopically. In the other 5 cases, the loose bodies were in the distal radioulnar joint, and arthrotomy was needed to remove them. After removal of the loose bodies, the pain was relieved in all cases without any surgical complications. CONCLUSIONS: Loose bodies in the wrist joint should be included in the differential diagnosis for chronic wrist pain. Wrist arthroscopy is of value because the preoperative diagnosis is usually difficult.

Adolescent↗

Snapping annular ligament of the elbow joint in the throwing arms of young brothers.

We examined young brothers with symptomatic snapping elbow in the throwing arm. Arthroscopic examination confirmed the mechanism of snapping, in which loose and protruded annular ligament-like tissue covered the volar half of the radial head in elbow extension and uncovered the radial head in deep elbow flexion. Arthroscopic resection of the annular ligament-like tissue was performed in one brother. Histologic examination of the removed tissue showed degenerated ligament tissue. Excision of loose annular ligament abolished snapping. Contralateral elbows of the brothers also showed similar asymptomatic snapping. Researchers suggest that a hereditary factor contributing to loose annular ligament and repetitive microtrauma from throwing is the cause of symptoms.

Adolescent↗

The athlete's shoulder.

Throughout the ages, instability has been noted to be the underlying problem in shoulder dysfunction of the young, overhand-throwing athlete. Impingement and rotator cuff tears are progressive symptoms of this instability. The classic theory of impingement describes a mechanism for "outside impingement," which is most often seen in the older, nonathletic population. The mechanism for "inside impingement" in the younger, athletic population is a pinching of the cuff undersurface on the posterosuperior glenoid labrum. In this younger group, the first treatment of choice is rehabilitation. If that fails, the surgical procedure with successful outcome is the ACLR coupled with a progressive rehabilitation program.

Arthroscopy↗

A three-dimensional, six-segment chain analysis of forceful overarm throwing.

A three-dimensional, six-segment model was applied to the pitching motion of three professional pitchers to analyze the kinematics and kinetics of the hips, upper trunk, humerus and forearm plus hand of both the upper limbs. Subjects were filmed at 250 frames per second. An inverse dynamics approach and angular momentum principle with respect to the proximal endpoint of a rigid segment were employed in the analysis. Results showed considerable similarities between subjects in the kinetic control of trunk rotation about the spine's longitudinal axis, but variability in the control of trunk lean both to the side and forward. The kinetics of the throwing shoulder and elbow joint were comparable between subjects, but the contribution of the non-throwing upper limb was minimal and variable. The upper trunk rotators played a key role in accelerating the ball to an early, low velocity near stride foot contact. After a brief pause they resumed acting strongly in a positive direction, though not enough to prevent trunk angular velocity slowing, as the musculature of the arm applied a load at the throwing shoulder. The interaction moment from the proximal segments assisted the forearm extensor in slowing flexion and producing rapid elbow extension near ball release. The temporal onset of muscular torques was not in a strictly successive proximal-to-distal sequence.

Arm↗

Apophysitis of the acromion.

We treated three patients with apophysitis of the acromion. These patients were two male athletes 12 and 14 years of age, respectively, and one female athlete 13 years of age. They reported pain at the top of the shoulder during and after shoulder movement while playing sports but had no rest pain or disturbance of daily activities. Physical examination demonstrated marked local tenderness at the acromion and slight warmth. X-ray films showed sclerosis and irregularity of the secondary ossification center of the acromion. Bone scintigraphy carried out on one patient demonstrated increased uptake in that region. Conservative treatment was used for these patients. Recovery was gradual but satisfactory.

Acromion↗

The relevance of action in perceiving affordances: perception of catchableness of fly balls.

The catchableness of a fly ball depends on whether the catcher can get to the ball in time; accurate judgments of catchableness must reflect both spatial and temporal aspects. Two experiments examined the perception of catchableness under conditions of restricted information pickup. Experiment 1 compared perceptual judgments with actual catching and revealed that stationary observers are poor perceivers of catchableness, as would be expected by the lack of information about running capabilities. In Experiment 2, participants saw the 1st part of ball trajectories before their vision was occluded. In 1 condition, they started to run (as if to catch the ball) before occlusion; in another, they remained stationary. Moving judgments were better than stationary judgments. This supports the idea that perceiving affordances that depend on kinematic, rather than merely geometric, body characteristics may require the relevant action to be performed.

Adult↗

Optical trajectories and the informational basis of fly ball catching.

D. M. Shaffer and M. K. McBeath (see record 2002-02027-006) plotted the optical trajectories of uncatchable fly balls and concluded that linear optical trajectory is the informational basis of the actions taken to catch these balls. P. McLeod, N. Reed, and Z. Dienes (see record 2002-11140-016) replotted these trajectories in terms of changes in the tangent of optical angle over time and concluded that optical acceleration is the informational basis of fielder actions. Neither of these conclusions is warranted, however, because the optical trajectories of even uncatchable balls confound the information that is the basis of fielder action with the effects of those same actions on these trajectories. To determine the informational basis of fielder action, it is necessary to do the control-theory-based Test for the Controlled Variable, in which the informational basis of catching is found by looking for features of optical trajectories that are protected from experimentally or naturally applied disturbances.

Baseball↗

Adjustments to the correction for attenuation.

With respect to the often-present covariance between error terms of correlated variables, D. W. Zimmerman and R. H. Williams's (1977) adjusted correction for attenuation estimates the strength of the pairwise correlation between true scores without assuming independence of error scores. This article focuses on the derivation and analysis of formulas that perform the same function for partial and part correlation coefficients. Values produced by these formulas lie closer to the actual true-score coefficient than do the observed-score coefficients or those obtained by using C. Spearman's (1904) correction for attenuation. The new versions of the formulas thus allow analysts to use hypothetical values for error-score correlations to estimate values for the partial and part correlations between true scores while disregarding the independence-of-errors assumption.

Analysis of Variance↗

From eye movements to actions: how batsmen hit the ball.

In cricket, a batsman watches a fast bowler's ball come toward him at a high and unpredictable speed, bouncing off ground of uncertain hardness. Although he views the trajectory for little more than half a second, he can accurately judge where and when the ball will reach him. Batsmen's eye movements monitor the moment when the ball is released, make a predictive saccade to the place where they expect it to hit the ground, wait for it to bounce, and follow its trajectory for 100-200 ms after the bounce. We show how information provided by these fixations may allow precise prediction of the ball's timing and placement. Comparing players with different skill levels, we found that a short latency for the first saccade distinguished good from poor batsmen, and that a cricket player's eye movement strategy contributes to his skill in the game.

Adult↗

A rare anatomic variant of the superior glenohumeral ligament.

The attachment of the superior glenohumeral ligament (SGHL) to the upper pole of the glenoid is variable and 3 types have been described. We report an anatomic variant of SGHL attachment to the upper pole of the glenoid that has not heretofore been reported in the literature. In this case, the SGHL overrode the biceps origin, continued to the superior labrum posteriorly, and had no attachment to the middle glenohumeral ligament or the anterior labrum. This variant was detected during routine arthroscopic examination undertaken before surgery on a rotator cuff tear.

Adult↗

Split biceps femoris tendon reconstruction for proximal tibiofibular joint instability.

Recurrent instability of the proximal tibiofibular joint is an infrequently diagnosed abnormality. We present a new technique for reconstructing the joint using a split biceps femoris tendon passed through a bone tunnel in both the proximal tibial metaphysis and fibular head. The case report is also presented. The procedure offers an anatomic reconstruction and firm stabilization. It allows normal motion of the proximal tibiofibular joint and preserves the normal mechanics of the ankle. This procedure is an excellent alternative to resection of the fibular head, transarticular arthrodesis, or pseudoarthrosis focus at the fibular head.

Adult↗

Autologous chondrocyte repair of an articular defect in the humeral head.

Articular cartilage lesions remain a difficult problem for the patient and physician. A variety of procedures and treatments have been proposed to lessen symptoms and restore the articular surface. The knee joint has been the focus of the vast majority of these cartilage restoration procedures. Articular cartilage lesions of the humerus are significantly less common, and their management remains poorly defined. This paper presents a case report of a young athlete with a large full-thickness articular cartilage defect of the proximal humerus and subsequent treatment using autologous chondrocyte implantation.

Adolescent↗