Kinematics and kinetics of elite windmill softball pitching.

BACKGROUND: A significant number of time-loss injuries to the upper extremity in elite windmill softball pitchers has been documented. The number of outings and pitches thrown in 1 week for a softball pitcher is typically far in excess of those seen in baseball pitchers. Shoulder stress in professional baseball pitching has been reported to be high and has been linked to pitching injuries. Shoulder distraction has not been studied in an elite softball pitching population. HYPOTHESIS: The stresses on the throwing shoulder of elite windmill pitchers are similar to those found for professional baseball pitchers. STUDY DESIGN: Descriptive laboratory study. METHODS: Three-dimensional, high-speed (120 Hz) video data were collected on rise balls from 24 elite softball pitchers during the 1996 Olympic Games. Kinematic parameters related to pitching mechanics and resultant kinetics on the throwing shoulder were calculated. Multiple linear regression analysis was used to relate shoulder stress and pitching mechanics. RESULTS: Shoulder distraction stress averaged 80% of body weight for the Olympic pitchers. Sixty-nine percent of the variability in shoulder distraction can be explained by a combination of 7 parameters related to pitching mechanics. CONCLUSION: Excessive distraction stress at the throwing shoulder is similar to that found in baseball pitchers, which suggests that windmill softball pitchers are at risk for overuse injuries. Normative information regarding upper extremity kinematics and kinetics for elite softball pitchers has been established.

Effects of Pronated and Supinated Foot Postures on Static and Dynamic Postural Stability.

Context: The foot is the most distal segment in the lower extremity chain and represents a relatively small base of support on which the body maintains balance (particularly in single-leg stance). Although it seems reasonable that even minor biomechanical alterations in the support surface may influence postural-control strategies, the implications of a hypermobile or hypomobile foot on balance have received little attention to date.Objective: To determine if supinated and pronated foot types influence measures of static and dynamic balance.Design: Participants were assigned to 1 of 3 groups depending on foot type, as defined by navicular-drop measures: pronated (>/=10 mm), neutral (5-9 mm), or supinated (

Treatment of stress fractures in athletes with intravenous pamidronate.

OBJECTIVE: To determine if the use of a second-generation biphosphonate, pamidronate, is an effective treatment option for stress fractures in intercollegiate athletes. Pamidronate is successfully used to increase bone mass in patients with Charcot arthropathy and osteoporosis. DESIGN: Case series. SETTING: Academic sports medicine clinic with primary responsibility for intercollegiate athletics. PARTICIPANTS: Five intercollegiate female athletes. INTERVENTIONS: Intravenous pamidronate administered weekly for a total of 5 treatments. MAIN OUTCOME MEASUREMENT: Athletes' ability to continue training without restrictions. RESULTS: Four of 5 treated athletes were able to continue training and competition within 1 week of treatment. CONCLUSIONS: Pamidronate may be a useful adjunct to the treatment of stress fractures.

Patellar tracking during simulated quadriceps contraction.

The current study compared patella tracking during simulated concentric and eccentric quadriceps contractions in 12 knees from cadavers using a three-dimensional electromagnetic tracking system. The patella shifted (translated) and tilted medially during approximately the initial 22 degrees tibiofemoral flexion. The patella then shifted and tilted laterally for the remaining arc of tibiofemoral flexion (90 degrees). At 90 degrees tibiofemoral flexion, the patella had an orientation of lateral patella shift and lateral patella tilt. Patella shift was significantly more lateral between 40 degrees and 70 degrees tibiofemoral flexion during concentric quadriceps action than during eccentric contraction. Patella tilt was significantly more lateral between 45 degrees and 55 degrees tibiofemoral flexion during concentric quadriceps contraction than during eccentric action. No other significant differences were seen between the quadriceps contraction conditions. The current study supports the hypothesis that patellar instability is most likely a result of various anatomic and physiologic factors causing a failure of the extensor mechanism to deliver the patella into the femoral sulcus and that a patellar dislocation rarely would occur in a normal knee.

Rotator Cuff Impingement Syndrome in Sports.

In brief 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.