Abstract
Injection drug use can impair mobility. When mobility is impaired in combination with other potential pathologic changes to the veins, muscles, and joints of the lower legs, chronic venous disorders can develop. The heel-rise test, an assessment of eccentric-concentric muscle action of calf muscle function with regard to plantar flexion, can be used to measure ankle mobility. To examine the test-retest reliability and construct validity of the heel-rise test in relation to chronic venous disorders in persons with a history of injection drug use (N = 104), a test-retest study (M = 45.9 ±12.9 days from first to second test) was conducted. Participants were assessed for chronic venous disorders of the legs and walk time; they also completed the heel-rise and Tinetti Balance and Gait tests. Test-retest reliability was found to be good for full heel rise of right and left legs (ICC = .66 and .67, respectively). Heel-rise performance was positively correlated with balance (r = .38 to .47) and gait (r = .38 to .45) and negatively related to walk time (r = -.30 to -.35) (P <0.01). Participants who injected in the groin, legs, or feet performed fewer heel rises than those who injected in the arms and upper body only or those who did not inject drugs. Chronic venous disorders accounted for 7% to 17% of the variance in heel rise. The heel-rise test as a measure of calf muscle function is supported by these results, implicating the role of mobility restriction in the etiology of venous disease. Although more research is needed regarding its performance, the heel-rise test may be a low-cost, noninvasive screening or assessment tool in a variety of outpatient settings. [PUBLICATION ABSTRACT]