The influence of lower-extremity muscle force on gait characteristics in individuals with below-knee amputations secondary to vascular disease.

BACKGROUND AND PURPOSE: The purpose of this study was to establish the relationship between isometric muscle force and temporal-spatial gait characteristics for individuals who have had a below-knee amputation secondary to vascular disease. SUBJECTS: Twenty-two individuals (15 male, 7 female) with dysvascular below-knee amputations participated. The male subjects were aged 35 to 72 years (x=59.6, SD=11.1), and the female subjects were aged 54 to 68 years (x=60.5, SD=5.1). Methods. The subjects underwent stride analysis during free-speed and fast walking, as well as bilateral isometric force testing of their remaining hip, knee, and ankle muscles. RESULTS: Stepwise regression analysis revealed that hip extensor force on the amputated side was the only predictor of both free speed (gamma=.50) and fast speed (gamma=.72). Hip abduction force of the sound++ limb was correlated with cadence for both free-speed trials (gamma=.57) and fast-speed trials (gamma=.57). Sound-side knee extensor force was related to free-speed stride length (gamma=.44), whereas residual-limb knee extensor force predicted stride length during fast walking (gamma=.67). CONCLUSION AND DISCUSSION: These results indicate that adequate force is necessary in both residual and sound limbs to improve functional gait ability and that ther hip extensors and abductors and the knee extensors should be emphasized in the rehabilitation of individuals with below-knee amputations.

Isometric shoulder torque in subjects with spinal cord injury.

The etiology of shoulder pain in spinal cord injured (SCI) patients has been attributed to overuse, with dysfunction being more prevalent as the time since injury increases. Impingement syndrome, the most common diagnosis in this population, may be related to weakness of the rotator cuff and shoulder girdle musculature. Shoulder dysfunction is greater in subjects with SCI than in able-bodied patients; consequently, this study compares isometric strength of quadriplegic and paraplegic subjects to able-bodied controls. Peak isometric torque for internal rotation, external rotation, and scapular elevation was assessed using a Lido isokinetic dynamometer. The strength (torque) values of the quadriplegic group were significantly lower than the control group and paraplegic group for all motions tested (p < .0005). The only significant difference between the paraplegic and able-bodied groups was found with internal rotation (p < .0001). These results indicate that quadriplegic patients may be at greater risk for shoulder pathology because of both muscular limitation and increased functional demand.