A review of selected noncontact anterior cruciate ligament injuries in the National Football League.

During five football seasons, from 1989 through 1993, 61 surgically proven, noncontact, anterior cruciate ligament injuries, were identified from among 22 National Football League teams. The variables of surface, shoe type, playing conditions, and whether or not the shoe was spatted were identified for each reported injury. Forty noncontact injuries occurred in conventional cleated shoes on natural grass, and 21 occurred on an artificial surface. Almost half of all injuries (47.5%) occurred during game-day exposures despite the fact that the practice versus game-day exposure rate was 5:1. Of these injuries, 95.2% (N = 58) occurred on a dry field. The factors of cleat and shoe type, type of surface (natural versus artificial), surface conditions (wet/dry), and the effect of "spatting" a shoe are presented. The significance of these factors and their likelihood to be associated with injury is analyzed by use of a statistical tool, the incidence density ratio.

Cybex evaluation of the relationship between anterior and posterior compartment lower leg muscles.

Twenty adult males were tested with the Cybex II isokinetic dynamometer, comparing in each leg the torque produced by the anterior and posterior muscle compartments. Significant torque is produced by the gastroc soleus muscle group, even when the knee is bent 90 degrees. There is a significant increase in anterior compartment dorsiflexion torque produced with the knee in extension as compared to flexion. There is no difference in right or left handedness in comparing the results of torque generation in the lower extremity. On the average, dorsiflexion torque is approximately one-third of plantarflexion torque at slow speeds and half that of plantarflexion at fast speeds.

Gait analysis. Alterations in support phase forces using supportive devices.

This study documents changes in momentary distribution of forces under the foot, comparing barefoot gait to that with heel cups, medial arch supports, and low-dye taping. Cholesterol crystal force plate analysis and a computerized Kistler force platform were used in the study. Low-dye taping or a heel cup significantly diminished the duration of forces under the midfoot, medializing the instant center of forces. A medial arch support shifted the instant center of forces laterally, though it did not diminish the duration of forces under the arch. The relationship between these alterations of force distribution and the treatment of common runner's ailments such as plantar fasciitis, posterior tibial tendinitis, metatarsalgia, and shin splints is much clearer in the light of these results.