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.

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.

The purpose of this study was to assess the reliability of the Closed Chain Rider System (Mettler Electronics) between exercise sessions and to determine the effects of limb dominance using muscle force and work measures during closed chain leg press exercise. Thirty-nine recreationally active college students underwent identical testing on two occasions, during which each subject performed five reciprocal leg press movements at speeds of 10, 15, and 20 in./s while seated. Average force, total work, and linear range of motion were recorded. Reliability values for average force and work were clinically acceptable for the dominant and nondominant limbs. The dominant limb produced greater average force and total work versus the nondominant limb, and average linear ROM was similar between the dominant and nondominant limbs. Differences in the torque and work values observed suggest that the clinician must be aware of differences between the dominant and nondominant limbs when used for comparative purposes.

. Dr Liu is currently at the School of Kinesiology, Auburn University, AL. Context:The mechanical property of stiffness may be important to investigating how lateral ankle ligament injury affects the behavior of the viscoelastic properties of the ankle complex. A better understanding of injury effects on tissue elastic characteristics in relation to joint laxity could be obtained from cadaveric study.Objective: To biomechanically determine the laxity and stiffness characteristics of the cadaver ankle complex before and after simulated injury to the anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL) during anterior drawer and inversion loading.Design: Cross-sectional study. Setting: University research laboratory.Patients or Other Participants: Seven fresh-frozen cadaver ankle specimens.Intervention(s): All ankles underwent loading before and after simulated lateral ankle injury using an ankle arthrometer. Main Outcome Measure(s):The dependent variables were anterior displacement, anterior end-range stiffness, inversion rotation, and inversion end-range stiffness.Results: Isolated ATFL and combined ATFL and CFL sectioning resulted in increased anterior displacement but not end-range stiffness when compared with the intact ankle. With inversion loading, combined ATFL and CFL sectioning resulted in increased range of motion and decreased end-range stiffness when compared with the intact and ATFL-sectioned ankles.Conclusions: The absence of change in anterior end-range stiffness between the intact and ligament-deficient ankles indicated bony and other soft tissues functioned to maintain stiffness after pathologic joint displacement, whereas inversion loading of the CFL-deficient ankle after pathologic joint displacement indicated the ankle complex was less stiff when supported only by the secondary joint structures.Key Words: ankle instability, joint laxity measurement, ankle sprains Key PointsThe injury mechanism consisted of serial sectioning of the major anatomic support structures of the lateral ankle complex. Anterior displacement was greater in the ankles with isolated anterior talofibular ligament (ATFL) sectioning and combined ATFL and calcaneofibular ligament (CFL) sectioning than in the intact ankles, but end-range stiffness did not increase after lateral ligament sectioning, indicating that bony and other soft tissues functioned to maintain anterior stiffness after pathologic joint displacement. With inversion loading, ankle-complex rotation increased and end-range stiffness decreased after CFL sectioning, indicating that the ankle complex was less stiff when supported only by the secondary joint structures.

Intervention(s): Each ankle underwent anteroposterior (AP) and inversion-eversion (I-E) loading using an ankle arthrometer.Main Outcome Measure(s): Recorded anterior, posterior, and total AP displacement (millimeters) at 125 N and inversion, eversion, and total I-E rotation (degrees) at 4 Nm.Results: Women had greater ankle-complex motion for all variables except for posterior displacement. Total AP displacement of the ankle complex was 18.79 6 4.1 mm for women and 16.70 6 4.8 mm for men (U 5 3742.5, P , .01). Total I-E rotation of the ankle complex was 42.106 6 9.06 for women and 34.136 6 10.16 for men (U 5 2807, P , .001). All variables were normally distributed except for anterior displacement, inversion rotation, eversion rotation, and total I-E rotation in the women's ankles and eversion rotation in the men's ankles; these variables were skewed positively.Conclusions: Our study increases the available database on ankle-complex motion, and it forms the basis of norm-referenced clinical comparisons and the basis on which quantitative definitions of ankle pathologic conditions can be developed.Key Words: normal distribution, flexibility Key PointsN This study increases the available database on ankle-complex motion and forms the basis of norm-referenced clinical comparisons.N Women had greater ankle range of motion than men, and all of the range-of-motion variables measured were normally distributed except for anterior displacement, inversion rotation, eversion rotation, and total inversion-eversion rotation, which showed a higher incidence toward hypermobility.N Our findings are clinically important because they will assist in the clinical decision-making process, enabling comparisons to be made with individual patient data and enabling quantitative definitions of ankle conditions to be developed.