Arthur M. Pappas

Biomechanics of baseball pitching: A preliminary report

Fifteen professional major league pitchers were filmed with high speed cinematography. One hundred forty- seven pitches were analyzed using an electromagnetic digitizer and a microcomputer. Three phases of throw ing were studied: cocking, acceleration, and follow- through. The cocking phase is the period of time be tween the initiation of the windup and the moment at which the shoulder is in maximum external rotation. This phase occurs in approximately 1500 ms, and the shoulder is brought into an extreme position of external rotation. The acceleration phase and the initial stages of the follow-through phase produce extraordinary de mands on the shoulder and elbow. The acceleration phase begins with the throwing shoulder in the position of maximum external rotation and terminates with ball release. This phase occurs in approximately 50 ms, and peak angular velocities averaging 6,180 deg/sec for shoulder internal rotation and 4,595 deg/sec for elbow extension were measured. The follow-through phase begins at ball release and continues until the motion of throwing has ceased. This phase occurs in approximately 350 ms.

Rehabilitation of the pitching shoulder

Shoulder pain is a common complaint among baseball pitchers. Frequently, the nature of shoulder pathology can be traced to lack of flexibility and muscular imbal ance. This paper describes: (1) the normal biomechanics of a properly functioning shoulder during a baseball pitch, (2) pathomechanics of shoulder problems, (3) flexibility requirements of the throwing shoulder, and (4) the muscular balance necessary for an effective throwing shoulder. Appropriate examination procedures are de scribed along with remedial exercises which ensure normal glenohumeral motion and integrated muscle action.

Avulsion fractures of the pelvis

Avulsion fractures of the pelvic apophyses are seen infrequently but they show a consistent pattern in mechanism, patients age, symptoms, physical findings, and roentgenographic appearance. Some disagree ment exists in the literature concerning the treatment of these fractures. This study indicates that early diag nosis and a carefully directed nonoperative treatment program will produce positive results for avulsion frac tures of the pelvis. Twenty-seven cases of acute avul sion fracture of the pelvis were successfully treated in a directed nonoperative program.

Posterior Ossification of the Shoulder: The Bennett Lesion Etiology, Diagnosis, and Treatment

We report a series of ossific lesions of the posterior inferior glenoid in a group of elite baseball players. We hope to clarify the etiology, diagnosis, and treatment of the Bennett lesion. From August 1985 to August 1991, we identified six professional baseball pitchers and one college pitcher with evidence of ossification of the shoul der on plain radiographs, computed tomography, or magnetic resonance imaging. Arthroscopic examina tion was performed in all cases. All seven players had identifiable posterior labral injury on arthroscopic ex amination ; six of these seven also had varying degrees of undersurface posterior rotator cuff damage. No an terior tissue damage, anterior instability, or subacromial impingement was noted. No ossification was identified arthroscopically. Intraarticular labral and rotator cuff tears were debrided arthroscopically and patients un derwent rehabilitation for 4 to 6 months after surgery. Six of the seven athletes returned to preinjury perform ance levels; however, one pitcher is no longer playing competitive baseball. The Bennett lesion is an extraarticular posterior os sification associated with posterior labral injury and pos terior undersurface rotator cuff damage. It is not, how ever, a result of traction stresses in the region of the triceps insertion. Recognition is important for identifi cation and treatment of the lesion and associated patho logic damage.

Wrist Kinematics During Pitching A Preliminary Report

A computerized hand and wrist motion analysis sys tem was modified to capture data at a rate of up to 1000 Hz. Using this system, wrist flexion and exten sion data were collected on five right-handed profes sional pitchers (75 pitches). A wrist position versus time graph was generated for each pitch. The pitch data produced a reproducible analysis of motion for the majority of the pitches regardless of pitcher. Based on the graphic display of data points, four phases of wrist motion during a pitch were identified. The first phase is the cocking phase, or the motion of the wrist as it moves into maximum extension. This is then followed by the most explosive phase, the ac celeration phase, which represents ball propulsion. At ball release, the wrist progresses through flexion and there is a consistent decrease in wrist velocity, known as the deceleration phase. Finally, there is the re covery phase, or the return of the wrist toward neutral. Average values for wrist range of motion, length of phase, and angular velocity (degrees per second) were calculated for each phase of the pitch. This study represents a major step toward quantifying mo tion of the wrist during a pitch. The ability to quantify this motion may prove valuable in the assessment of throwing athletes after injury and rehabilitation.

Chronic, painful ankle instability in skeletally immature athletes : Ununited osteochondral fractures of the distal fibula

We report 10 cases of chronic, painful ankle instability in skeletally immature athletes associated with un united osteochondral fragments of the distal fibula. All the patients experienced multiple inversion injuries with recurrent pain and instability that failed to improve after a supervised exercise and rehabilitation program. Osteochondral fragments of the distal fibula were vis ible on all standard radiographs of the affected ankles. Treatment consisted of operative excision of the bony fragment and an anatomic nonaugmented repair of the lateral ligament complex and capsule. All 10 patients were available for long-term followup an average of 6.5 years (±2) after surgery; all ankles improved function ally, with no recurrences of instability.

Baseball: too much on a young pitcher's shoulders?

In brief Adolescent baseball pitchers who pitch too frequently may place too great a demand on their rapidly growing shoulders, resulting in damage that may curtail and possibly end their playing c...