Citations

Eighty-six male high school ice hockey players partic ipated in this prospective study to determine both the incidence of injury in high school ice hockey and the influence of physical, situational, and psychosocial fac tors. Physical factors included height, weight, vision, previous injuries, musculoskeletal abnormalities, and injuries present at the time of screening evaluations. Situational factors examined were level of participa tion, playing time, player position, and games versus practices. Psychosocial factors such as confidence, stress, social support, positive states of mind, and mood states were also examined to determine their influences on injury. Twenty-seven injuries occurred during the 1994 to 1995 season. As hypothesized, the overall incidence of injury in high school hockey games (34.4 per 1000 player-game hours) was less than the incidence of injury in Junior A hockey (96.1 per 1000 player-game hours) and was more than previously re ported for Bantam youth hockey (10.9 per 1000 player- game hours). Injuries occurred more often in games than in practices, usually as a result of collisions. Phys ical factors such as player position and previous inju ries did not significantly predict injuries, but players in the high playing time group were more likely to be injured. Psychosocial factors of low vigor and high fatigue as measured by the Incredibly Short Profile of Mood States (ISPOMS) significantly predicted high school ice hockey injuries.

We defined foot and ankle motion with respect to the neutral position. Thirteen normal fresh-frozen speci mens of the human foot were used. The foot was placed in the extreme positions of pronation, supina tion, dorsiflexion, and plantar flexion, and positions of multiple bones were monitored simultaneously with a magnetic tracking device to determine rotation of the talocrural, subtalar, metatarsal-navicular, and talo navicular joints under the various conditions. In prona tion, the most rotation occurred at the metatarsal-na vicular level, followed by the navicular-talar, talar-tibial, and calcaneal-talar levels. In supination, most rotation occurred at the navicular-talar level, followed by the calcaneal-talar, talar-tibial, and metatarsal-navicular levels. In dorsiflexion, most rotation occurred at the talar-tibial level, followed by the navicular-talar, calca neal-talar, and metatarsal-navicular levels. In plantar flexion, most rotation occurred at the talar-tibial level, but there was considerable motion at the navicular- talar, metatarsal-navicular, and calcaneal-talar levels. Understanding the specific joint motions that occur with various positions of the foot and ankle is important because measurements of joint mobility may assist in establishing diagnoses, monitoring clinical conditions, determining indications for operative treatment, as sessing results of treatment, and following the progress of rehabilitation.

The purpose of this study was to establish a data base on the isokinetic eccentric muscular performance char acteristics of external and internal rotator muscles in the shoulders of professional baseball pitchers. Con centric data are also included and compared with pre viously published concentric studies. Twenty-five pro fessional baseball pitchers were evaluated with a Kin- Com isokinetic dynamometer. The subjects tested had a mean age of 23.5 years and a mean body weight of 199 pounds. Eccentric and concentric isokinetic tests were performed at 60 and 120 deg/sec. The testing protocol was standardized for each subject. Test re sults indicated no statistically significant difference in mean torque between throwing and nonthrowing shoulders for either external or internal rotator muscle groups. Eccentric strength was significantly greater than concentric strength for all muscle groups tested. The external-to-internal rotator muscle strength ratios were well above those previously published for high school through professional pitchers. Mean torque-to- lean body weight ratios were also included to establish a data base. This study establishes one of the first data bases for eccentric isokinetic muscle strength of shoul der rotator muscles in professional baseball pitchers. The data may help clinicians prevent and rehabilitate shoulder injuries in professional throwing athletes.

The purpose of this study was to analyze intersegmen tal forces at the tibiofemoral joint and muscle activity during three commonly prescribed closed kinetic chain exercises: the power squat, the front squat, and the lunge. Subjects with anterior cruciate ligament-intact knees performed repetitions of each of the three exer cises using a 223-N (50-pound) barbell. The results showed that the mean tibiofemoral shear force was posterior (tibial force on femur) throughout the cycle of all three exercises. The magnitude of the posterior shear forces increased with knee flexion during the descent phase of each exercise. Joint compression forces remained constant throughout the descent and ascent phases of the power squat and the front squat. A net offset in extension for the moment about the knee was present for all three exercises. Increased quadri ceps muscle activity and decreased hamstring muscle activity are required to perform the lunge as compared with the power squat and the front squat. A posterior tibiofemoral shear force throughout the entire cycle of all three exercises in these subjects with anterior cru ciate ligament-intact knees indicates that the potential loading on the injured or reconstructed anterior cruci ate ligament is not significant. The magnitude of the posterior tibiofemoral shear force is not likely to be detrimental to the injured or reconstructed posterior cruciate ligament. These conclusions assume that the resultant anteroposterior shear force corresponds to the anterior and posterior cruciate ligament forces.

This study compared and quantified electromyographic muscle activation of the rotator cuff with the isometric torque generated by performing shoulder rotation in various positions. Twenty healthy volunteers were tested in 29 shoulder positions. Using a Cybex II dy namometer synchronously with electromyography, surface electrodes were placed over the pectoralis major muscle and three parts of the deltoid muscle. Intramuscular wire electrodes were inserted into the four rotator cuff muscles. We found that the greatest external rotation isometric force is generated in the frontal and scapular planes in the neutral or full internal rotation positions. The sagittal, dependent, and the scapular plane with 45° of elevation in rotational posi tions of either full or half external rotation generated the greatest torques for internal rotation isometric force. The rotator cuff muscles generated greatest electro myographic activity in neutral to midrotational posi tions. The scapular plane with 90° of shoulder eleva tion in neutral rotation best isolated the subscapularis muscle. The infraspinatus-teres minor muscles were isolated in the sagittal plane with 90° of shoulder ele vation in a half externally rotated position. We were unable to isolate the supraspinatus muscle in any of these tested positions. These positions are recom mended for manual muscle testing and for strengthen ing these muscles.

This 3-year prospective cohort observational analysis of elite amateur hockey players ranging in age from 17 to 20 years on a United States Hockey League team de scribes ice hockey injuries using a strict definition of injury, standardized reporting strategies, and diagnosis by a team physician. One hundred forty-two injuries were recorded for an on-ice injury rate of 9.4 per 1000 player hours. A player was 25 times more likely to be injured in a game (96.1 per 1000 player-game hours) than in practice (3.9 per 1000 player-practice hours). Game-related injuries were more frequent in the third period, and practice-related injuries occurred more of ten in the first third of the season. Collisions represented 51% of the total injuries. The most common types of injuries were strains, lacerations, contusions, and sprains. The face and the shoulder were most fre quently injured. A facial laceration was the most com mon injury; acromioclavicular joint sprain was the sec ond most common injury. Facial lacerations typically occurred in games and were stick related. Further re search is necessary to determine if injuries in Junior A amateur ice hockey can be reduced by mandatory full facial protection, enforcement of existing rules, im provement in shoulder pad design, and by focusing more attention on stretching programs.

The purpose of this study was to review patellar tendon ruptures in athletes treated with surgical repair. Six pa tellar tendon ruptures in five athletic patients were iden tified at our institution between 1980 and 1990. All pa tients had operative debridement and primary repair of the ruptured patellar tendon using nonabsorbable su tures passed through patellar drill holes at an average of 2.5 days after injury. Personal interview, physical ex amination, roentgenographic evaluation, and isokinetic strength testing were performed at an average of 6 years after surgery. At final followup, no patient had complaints referable to the patellar tendon repair; all were able to achieve their premorbid levels of sports at an average of 18 months after injury. No patient thought that the surgically repaired knee was unstable or activity-limiting. All patients demonstrated full range of motion and strength equal to or greater than that of the noninjured side. One patient required an arthroscopic lateral release for lateral patellar facet pressure syn drome with an excellent result. No complications oc curred ; no other reoperations were required. Complete disruption of the patellar tendon is an uncommon injury in athletic individuals without predisposing medical con ditions. After acute operative repair and aggressive re habilitation, an excellent and enduring functional outcome can be expected.

The contribution of axial arm rotation to translation of the humeral head with the arm in the hanging position was examined using nine fresh-frozen cadaveric shoulders. Three standard clinical tests were simulated: anterior and posterior translation and sulcus tests. In both the anterior translation and sulcus tests, anterior and infe rior displacements were significantly restricted in inter nal rotation but not in neutral and external rotation. In the posterior translation test, no significant differences in displacement could be observed in internal, neutral, or external rotation. Since anterior and inferior translations of the humeral head were significantly affected by the rotation of the arm, we recommend that the anterior translation and sulcus tests be performed in various rotations.

The purpose of this study was to compare 2 radio graphic methods for measuring anteversion and to de termine whether glenoid anteversion is a significant fac tor in recurrence of instability after anterior repair. West Point axillary roentgenograms were obtained in 128 pa tients (138 shoulders) at a mean of 9 years after sur gery. Two methods to measure glenoid anteversion were compared: The angle between the glenoid and the body of the scapula, and the angle between the glenoid and the posterior margin of the acromion. There was less variation in the measurements using the glenoid margin-posterior acromion angle. By this method, an teversion was 11 ° ± 4° for the 15 patients with multiple (2 or more) recurrences, 8° ± 3° for the 15 patients with 1 recurrence, and 6° ± 5° for the 109 patients with no recurrences. Although these differences are statistically significant (P = 0.003), they probably are not clinically important because they are small (mean of only 5°). The differences obtained by measuring the angle between the glenoid and the body of the scapula were not sta tistically significant.