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Study Design: A within-subject experimental design was used with to measure the effect of calf-stretching exercises on the resistive torque during passive ankle dorsiflexion in a group of 20 healthy men (aged 21 to 40)., Objectives: The purpose of this study was to determine if the performance of calf-stretching exercises would produce a decrease in resistive torque during passive ankle dorsiflexion., Background: Calf-stretching exercises are widely used in sporting, fitness, and rehabilitation settings yet the effects of stretching on the passive mechanics of the ankle joint are not well understood., Methods and Measures: A KIN-COM isokinetic dynamometer was used to measure the passive resistive torque of the ankle while the joint complex was moved through return cycles from 10 degrees plantarflexion to 10 degrees dorsiflexion at a constant velocity of 6 degrees/s. Each subject's right or left ankle was randomly assigned to either a control or an experimental condition. The latter underwent a total of 4 static stretches, each lasting 30 seconds., Results: The main findings of the study were that the calf-stretching exercises did not produce a significant reduction in the resistive torque during ankle dorsiflexion, as measured by the peak to peak torque at 10 degrees of ankle dorsiflexion or in the center range of the hysteresis loop at 0 degree dorsiflexion., Conclusion: Static calf-stretching exercises of short duration did not reduce the passive resistance of the connective tissue within the surrounding muscle and joint structures in the ankles of healthy young men.

A portable, lightweight home ankle exerciser was designed and built by the Biomedical Engineering Department of University Hospital in London, Ontario, Canada. The ankle exerciser incorporates several unique features that overcomes the drawbacks of exercise equipment presently available. For optimal muscle strengthening, the resistance offered by the device matches the strength curve of the ankle muscles. The magnitude of the resistance can be widely varied to accommodate any subject. Resistance is generated by a slip clutch rather than by springs or weights which can be cumbersome and potentially dangerous. One of the considerations in the design of the ankle exerciser was to monitor subject compliance with the exercise regimen. This is accomplished with a battery-operated monitoring unit mounted on the device. The exerciser is instrumented with a battery-powered torque transducer and digital display unit that enables the subject and assessor to monitor the exercise resistance level at a glance.

The primary aim of this research project was to develop a method to quantify a specific variable of neuromuscular function, passive stiffness of the ankle. It was then used to determine if values for the outcome measure varied with age and sex in a sample of elderly men and women between 55 and 85 years old. Subjects were screened for medical conditions contraindicative to testing, e.g. severe arthritis, other history of bone or muscle disorders, ankle fracture, neural disorder causing spasticity or contracture. A rotatable footplate which recorded position and resistive torque with a potentiometer and strain gauge, respectively, was linked to an electric, computer-controlled torque motor. Passive elastic stiffness, defined as the slope of the passive resistance curve at 10 degrees dorsiflexion (in N.m/degree), was greater in males, (p < .001), and increased with age (p = .002). There was a significant effect of age group on passive range of motion (ROM) values for ankle dorsiflexion (p < .001), but also a significant sex by age interaction (p = .001). Females showed a large drop from a mean of 19.3 degrees +/- 3.2 in the youngest group (55-60 yr) to 12.1 degrees +/- 5.5 in the 81 to 85 yr olds. Corresponding mean values for the middle-aged males were 15.4 degrees +/- 4.3 versus 13.1 degrees +/- 3.5 of dorsiflexion in the group of 81 to 85 yr old men. It was concluded that passive ROM of the ankle into dorsiflexion showed decreases in the elderly, which seemed to reflect less complaint tissue structures.

We investigated whether values for passive resistive torque, dorsiflexion strength, and active mobility of the ankle joint varied with age in a randomly selected sample of middle-aged and elderly males and females. The main effects of sex and age group were significant, without an interaction effect, on values for passive resistive torque and voluntary strength. The trends indicated that females had lower values for both variables and that passive torque increased and strength decreased with respect to age. Dorsiflexion range of motion also showed a highly significant trend to decrease across age groups, and more so for females than males. Mean values for middle-aged men vs old men went from 20.0 to 13.5 degrees, while corresponding values for women decreased from 20.7 degrees of dorsiflexion to 10.1. Functional ankle movement thus becomes limited with age, but could be improved by strengthening weak dorsiflexor muscles.

The purpose of the study was to evaluate passive joint stiffness in ankles of young (aged 21-40 years; n = 15), middle-aged (aged 41-60 years; n = 15), and young elderly (aged 61-80 years; n = 15) women. The effect of knee position on passive joint stiffness was also evaluated by testing the subjects with the knee flexed (90 degrees) and with the knee extended (0 degrees). A torque motor system was used to record angular displacement and resistive torque during a 6 degrees/sec ankle rotation from 10 degrees of plantar flexion to 10 degrees of dorsiflexion (DF). Passive torque and passive elastic stiffness were measured at 0, 5, and 10 degrees of DF. Both measures increased nonlinearly as the ankle was rotated into DF, but showed no significant differences between the three age groups tested. There was also no significant difference in the passive stiffness measurements when the knee was flexed or extended. We concluded that within the range of motion tested, the factors of age and knee position do not affect the passive stiffness observed in the ankle joints of healthy women. We have now established baseline values of passive ankle joint stiffness for healthy women during DF within a functional ROM, which will be useful in the clinical evaluation of passive ankle joint stiffness and in studies where treatment efficacy is being investigated.