A retrospective study of gymnastics injuries to competitors and noncompetitors in private clubs.

The purpose of this study was to determine the number and types of injuries which occur to competitive and noncompetitive gymnasts in private clubs. Secondary purposes were to determine which events were most hazardous, and whether or not the ratio between participant and instructor, the availability of safety equipment, and the conditioning programs used affected the injury rate. The data show that gymnastics has a high injury rate for competitors, but a low injury rate for noncompetitors. The level of competition seems to be the most important factor related to rate of injury.

Developmental biomechanics. Effect of forces on the growth, development, and maintenance of the human body.

The purpose of this paper is to present an overview of growth principles that are influenced by mechanical factors. These general principles are followed by some biomechanical examples of the growth and development of weight-bearing body areas, and examples of growth principles and mechanics related to therapeutic applications.

The hip joint: structure, stability, and stress; a review.

A review of the structure of the hip joint as related to its stability is presented. The forces exerted at the hip and along the proximal end of the femur are discussed in relation to the anatomical position of bone and to normal stresses incurred during standing and gait. Clinical considerations of selected hip abnormalities include a review of changes in normal mechanical forces found in coxa valga, coxa vava, arthritis, and fracture.

Selective training of the vastus medialis muscle using EMG biofeedback.

The purpose of this study was to investigate if, in three weeks, the vastus medialis muscle could be trained to contract independently of the vastus lateralis muscle. Ten subjects attended electromyographic biofeedback training sessions five days a week for three weeks for one half hour each day. During the first two weeks the subjects concentrated on decreasing the activity level of the vastus lateralis muscle, and during the final week they tried to increase the vastus medialis muscle activity level. Significant differences were found in the change in muscle activity level of the vastus lateralis muscle over the first two weeks, in the change of muscle activity level of the vastus medialis muscle over the third week, and in the difference between vastus medialis and vastus lateralis muscle activity levels from the first to the third weeks.

Clinicians' use of research findings. A review of literature with implications for physical therapists.

The purpose of this paper is to review the literature regarding research utilization by human service professionals, discuss factors that may contribute to utilization, describe recommendations that have been suggested to increase research utilization, and make suggestions for future investigations about research utilization by physical therapists. The literature suggests that research information is not used routinely by human service professionals. The nature of research communication, the training and personal characteristics of human service professionals, and the practice environments of human service professionals, such as physical therapists, probably influence the degree to which research is utilized. Specific interventions may be effective at increasing research utilization by physical therapists. A number of possible research methods are available for evaluating the present state of research utilization by physical therapists and the effects of interventions on this utilization.

Contribution of pelvic and lower limb motion to increases in the angle of passive straight leg raising.

We undertook this study to determine the relative contributions of pelvic and lower limb motion to increases in the angle of passive straight leg raising in the sagittal plane. Seventeen healthy subjects underwent passive straight leg raising of their relaxed left lower limb while their right lower limb was held firmly against the table. Each subject's pelvis and left lower limb were marked so that cinematography could document motion of the pelvis and left lower limb during passive straight leg raising. Film analysis revealed that pelvic rotation began within 9 degrees of the beginning of passive straight leg raising and that the relative contribution of pelvic rotation to the angle of passive straight leg raising in relation to the horizontal plane increased in conjunction with the angle of straight leg raising. Clinicians using the passive straight-leg-raising test should be aware of the contribution of pelvic rotation to the angle of straight leg raising when interpreting test results.

Relationship between muscle length, muscle activity, and torque of the hamstring muscles.

The relationship between muscle length, integrated electromyographic activity, and torque of the biceps femoris muscle was investigated while the line of action of the muscle at the knee was held constant. Muscle length was changed by varying the hip joint angle. Sixteen subjects produced 1) maximal isometric contractions, 2) contractions with constant submaximal torque, and 3) contractions with constant submaximal muscle activity at four different hip positions (0, 45, 90, and 135 degrees of flexion). Simultaneous readings of hip angle, muscle torque, and raw and integrated electromyographic activity revealed that changes in muscle length influence production of integrated muscle activity and development of torque differently. During maximal isometric contraction, an increase in integrated electromyographic activity and a decrease in torque occurred as the muscle was shortened; the opposite occurred when the muscle was at lengthened positions. A greater difference in this relationship was noted when the respective electromyographic activity and torque were held constant. Some clinical questions were raised.

Health beliefs and health behaviors of physical therapists.

The purpose of this study was to examine the health beliefs and health behaviors of physical therapists. A survey questionnaire was sent to a 10% random sample of the physical therapists on the Texas licensure list for 1984, and 234 responses (69%) were used in the data analysis. The respondents tended to have positive health beliefs and good health behaviors in terms of a healthy life style. These findings have implications for physical therapists as role models for encouraging good health habits in their patients.

Effects of ankle dorsiflexion on active and passive unilateral straight leg raising.

The purpose of this study was to analyze the straight-leg-raising (SLR) maneuver while the ankle was fixed in dorsiflexion or relaxed in plantar flexion. Twenty-two healthy subjects underwent active and passive SLR with the ankle in each position. We used cinematography to document movement of the right lower limb and pelvis and electromyography to document hamstring muscle activity. Analyses of variance of the angles of maximum SLR and change in the pelvic position showed a significant F ratio (p = .01) among the active and passive trials. Post hoc analyses demonstrated significant differences (p = .01) between SLR with dorsiflexion and SLR with plantar flexion. The EMG activity among trials was not significantly different. The possible causes of the effects of dorsiflexion on SLR are discussed. We encourage clinicians to document and compare SLR with dorsiflexion and SLR with plantar flexion, and we recommend additional research to examine the relative influence of tissue structures on SLR.

Relationship of pelvic and thigh motions during unilateral and bilateral hip flexion.

We filmed the hip flexion movement with a 16-mm motion picture camera to determine if a synergistic relationship between the pelvis and thigh existed. Seventeen young subjects, whose pelvises and thighs were marked with tape, underwent active and passive, unilateral and bilateral hip flexion while in the supine position. Analysis of the film revealed that the hip flexion movement is composed of two components--pelvic rotation and flexion of the thigh on the pelvis. Between one fourth and one third of the hip flexion movement was the consequence of pelvic rotation. This rotation always occurred within the first 8 degrees of the hip flexion movement. When therapists evaluate and treat patients with disorders of the thigh, pelvis, or lumbar spine, they should be aware that these structures normally move in synergy with one another. We suggest that the pelvifemoral relationship be examined further in studies with a wide range of healthy subjects and patients with a variety of clinical disorders.

Electromyographic activity recorded from an unexercised muscle during maximal isometric exercise of the contralateral agonists and antagonists.

The purpose of this study was to determine if integrated electromyographic activity recorded from an unexercised muscle during contralateral exercise was dependent upon the contralateral muscle (agonist or antagonist) being exercised and upon the position of the unexercised limb. Twenty normal subjects participated in the study. Electromyographic activity was recorded, using surface electrodes, from the right rectus femoris and the right vastus lateralis muscles during four experimental conditions. Statistical analysis revealed that 1) integrated electromyographic activity recorded from the rectus femoris muscle during contralateral, isometric exercise was not significantly influenced by the position of the unexercised knee or the exercised contralateral muscle and 2) integrated electromyographic activity recorded from the vastus lateralis muscle during contralateral, isometric exercise was significantly greater when the unexercised knee was initially positioned in 10 degrees of flexion and the contralateral agonists were exercised. Integrated electromyographic activity recorded during contralateral exercise appeared to be related to the associated movement of the unexercised limb.

Isokinetic knee flexion and extension torque in the upright sitting and semireclined sitting positions.

We undertook this study to determine whether the isokinetic knee extension and flexion torque generated by 14 young healthy women was greater in the upright sitting test position or in the semireclined sitting test position. Testing was performed at 60 degrees/sec. Knee extension torque did not differ significantly between the two test positions. The subjects, however, did produce significantly greater knee flexion torque when upright compared with when semireclined (p less than .001). Therapists should recognize that the results of testing isokinetic knee extension in the two positions may be similar, but that the results of testing isokinetic knee flexion may be significantly different.

The effect of physical activity on ligamentous strength: an overview*.

A brief review of the literature pertaining to the strengthening of ligamentous tissue through physical activity is presented. Although literature exists supporting both sides of the question, the predominence of evidence seems to be in favor of improved ligamentous strength following physical activity. Despite the general agreement, the exact mechanism involved is unclear. It is also unclear whether the ligament or the ligament-bone interface is the site of increased strength. A review of the possible mechanisms involved, as well as a discussion of the influence of immobility on the validity of the experimental results, is presented. J Orthop Sports Phys Ther 1984;5(5):275-277.

Effectiveness of foot orthotic devices used to modify pronation in runners*.

Foot orthotic devices (FOD) are often used to treat excessive pronation and related problems of runners. In order to assess the effectiveness of FOD, 29 runners who used FOD were filmed on an outdoor track during three conditions: 1 ) barefoot, 2) running shoe, and 3) running shoe plus FOD. The barefoot data were not used because of marked variability. Comparison between the shoe and FOD conditions showed that only two of the six variables were statistically significant at the 0.05 level. Both the maximum angle of pronation and percentage of support time in pronation on the left foot were significantly decreased in the FOD trial. No significant differences were found between the shoe and FOD conditions for the other four variables (pronation velocity on both feet, maximum angle of pronation on the right foot, and percentage of support time spent in pronation on the right foot). The variability of these results support the conclusion that the type of FOD used in this study have questionable effectiveness in the treatment of excessive pronation. J Orthop Sports Phys Ther 1982;4(2):86-90.