The relationships between instrumented measurements of ankle and knee ligamentous laxity and generalized joint laxity.

AIM: The purpose of this study was to evaluate whether lower extremity joint laxity is a function of a particular joint and/or a generalizable characteristic (trait) of the person. Validated instrumented measurements of ankle and knee joint-specific laxity in the same individual were correlated to determine whether a relationship exists. In addition, ankle and knee joint-specific laxity were correlated with generalized joint laxity using the modified Beighton mobility index. METHODS: Fifty-seven male and female athletes were studied. We examined dominant ankle laxity using an ankle arthrometer and dominate knee anterior laxity using the KT 2000. The dominant ankle was loaded in anteroposterior (AP) drawer and inversion-eversion (I-E) rotation. Laxity was measured as total AP displacement (millimeters) after +/-125 N of applied force and total I-E rotation (degrees) was measured after +/-4 N x m of applied torque. The dominant knee was loaded with an anterior drawer and laxity (millimeters) was measured after manual maximum displacement. RESULTS: Non-significant correlations were observed among the test variables for generalized joint laxity (0.21 to 0.37; P>0.05) and instrumented ankle and knee joint laxity (0.19 to 0.21; P>0.05). When examined by gender, no statistically significant correlations (0.05 to 0.40; P>0.05) were found for either generalized laxity or instrumented ankle and knee joint laxity. CONCLUSIONS: These results imply that ankle and knee joint laxity are joint-specific and not generalizable.

Instrumented measurement of anteroposterior and inversion-eversion laxity of the normal ankle joint complex.

Manual examination is the most common method for the evaluation of ankle anteroposterior (AP) and inversion-eversion (I-E) laxity. Objective assessment data of normal ankle laxity must be provided before comparison with an injured ankle can be made. The purpose of this study was to compare AP translation and I-E rotation at three force loads between dominant and nondominant ankles and to assess the test-retest reliability of a portable arthrometer in obtaining these measurements. The arthrometer consists of a frame that is fixed to the foot, a pad that is attached to the tibia, and a load-measuring handle that is attached to the foot plate through which the load is applied. A six-degrees-of-freedom spatial kinematic linkage system is connected between the tibial pad and the foot frame to measure motion. Instrumented measurement testing of total AP displacement and I-E rotation of both ankles was performed in 41 subjects (21 men and 20 women; mean age, 23.8 +/- 4.4 years). Subjects had no history of ankle injury. Subjects were tested in the supine position while lying on a table with the knee secured in extension and the foot positioned at 0 degrees of flexion. Laxity was measured from total AP displacement (millimeters) during loading to 125 N of AP force and from total I-E rotation (degrees of range of motion) during loading to 4000 N-mm. Reliability was evaluated by calculating intraclass correlation coefficients (2,1) at 75 N, 100 N, and 125 N of AP force and at 2000, 3000, and 4000 N-mm torque loads. Mean differences for displacement and rotation between the dominant and nondominant ankles at each of the force and torque loads were analyzed by dependent t-tests. For both the dominant and nondominant ankles, respectively, the reliability coefficients at each of the force loads for AP displacement (range, 0.82-0.89) and I-E rotation (range, 0.86-0.97) were high. The t-test analyses showed no significant differences (P > or = 0.05) for total AP displacement or I-E rotation between the dominant and nondominant ankles at any of the force loads. The results are clinically useful in providing information about the reliability of measures at different AP and I-E force loads using a portable ankle ligament arthrometer.

Reliability and effects of arm dominance on upper extremity isokinetic force, work, and power using the closed chain rider system.

OBJECTIVE: The purpose of our study was to assess the reliability of the Closed Chain Rider System between exercise sessions and to determine the effects of arm dominance using muscle force, work, and power measures during closed chain chest-press exercise. DESIGN AND SETTING: Sitting subjects underwent identical testing on 2 occasions and performed 5 reciprocal chest-press movements at speeds of 51 and 76 cm/s. SUBJECTS: Thirty-eight healthy college students. MEASUREMENTS: Average force, total work, average power, and linear range of motion were recorded. Reliability was evaluated by calculating intraclass correlation coefficients. Mean differences between the dominant and nondominant arms for the measured variables were analyzed by dependent t tests. RESULTS: For both the dominant and nondominant arms at the 51 and 76 cm/s speeds, reliabilities of average force (range = 0.85 to 0.91), total work (range = 0.88 to 0.92), and average power (range = 0.86 to 0.89) were clinically acceptable. The dominant arm produced significantly greater average force, total work, and average power compared with the nondominant arm. CONCLUSIONS: Our results provide clinically useful information about the reliability of force, work, and power measures during multijoint bilateral chest-press movement. Clinicians should be aware of measured differences between dominant and nondominant arms.

The effects of a short-term exercise program on movement, pain, and mood in the elderly. Results of a pilot study.

Therapeutic effects of a short-term Tai Chi exercise program for the elderly were evaluated in a pretest-posttest quasi-experimental design. This pilot study evaluated changes in flexibility, balance, sway, pain, and mood after a short slow-motion exercise. The program consisted of a series of movements involving turning, shifting weight, bending, and arm movements in combination with diaphragmatic breathing with slow movements. The measured effects included improved balance, sway, range of motion, decreased perceived pain, and lessened trait anxiety. Participants included 11 elderly females. Instruments consisted of standard goniometry, the Multiple Affect Adjective Check List, stopwatch measures of single-leg stance and a tandem walk (sway), and visual analog measurement of pain. Findings included significant improvement (p = .05) in trait anxiety and pain perception. Improvements in mood, flexibility, and balance may have a profound effect on the incidence of falls, injuries, resulting disability, and overall quality of life.