Faculty Bibliography

INTRODUCTION/BACKGROUND:Foot progression angle (FPA) is a predictor of elevated regional plantar stresses and loads, which are indicators of dermal injury risk in individuals with diabetes mellitus and peripheral neuropathy (DMPN). FPA accounts for 15-45% of the variance in plantar stresses and loads in adults with DMPN. However, the biomechanical factors underlying an "out-toeing" gait pattern in this clinical population have not been examined. The primary purpose of this study was to identify static and dynamic predictors of foot progression angle magnitude in adults with and without DMPN. METHODS:Thirty-three adults with and 12 adults without diabetes mellitus participated. Hip rotation, ankle dorsiflexion, and resting calcaneal stance position were measured using a standard goniometer. Kinematic and kinetic data were collected during walking. RESULTS AND DISCUSSION/CONCLUSIONS:Static predictor variables did not significantly predict foot progression angle magnitude using multiple regression analysis. Of the dynamic predictor variables, thigh and shank lateral rotation accounted for 37% of foot progression angle variance (p<.01). CONCLUSIONS:Our results show that dynamic measures of external rotation of proximal segments (thigh, shank) during gait are strong predictors of foot progression angle. Static measures of limited joint mobility and joint position do not predict foot progression angle. These findings suggest that targeting the thigh and shank rotation using verbal or tactile cueing may be a potential strategy when trying to alter walking movement patterns towards decreasing external (lateral) FPA to minimize risk of elevated regional plantar stresses in adults with DMPN at risk for ulceration.

BACKGROUND:Sarcopenic (SP) indices are used to estimate loss of skeletal lean mass and function and to determine the prevalence of SP in older adults. It is believed that older women and men with lower skeletal lean mass will be weaker and have more functional limitations. PURPOSE/OBJECTIVE:(1) To classify community-dwelling older adults using 2 common SP indices: appendicular lean mass/height² (ALM/ht²) and skeletal muscle index (SMI), and (2) to determine each indices value as indicators of lower extremity strength and physical function. METHODS:The sample consisted of 154 community-dwelling older adults (111 women and 43 men; mean age = 82.4, SD = 3.6 years; mean body mass index = 25.8, SD = 4.4 kg/m). Each underwent whole-body dual-energy x-ray absorptiometry to assess lean mass. The 9-item modified Physical Performance Test and self-selected walking speed were used to evaluate function. Lower extremity strength was measured bilaterally using isokinetic dynamometry. RESULTS:The ALM/ht² index classified 75 participants (49%) as SP and 79 (51%) as nonsarcopenic (NSP). The SMI classified 129 participants (84%) as SP and 25 (16%) as NSP. There were no differences in functional measures between groups by gender using either index after classification. The ALM/ht index was more strongly correlated with peak torque of all lower extremity muscle groups (r = 0.276-0.487) compared with the SMI (r = 0.103-0.344). There was no relationship between SP index and physical function. DISCUSSION/CONCLUSIONS:There were marked differences in how 2 SP indices classified community-dwelling older adults. Lower extremity strength was lower in older women classified as SP than NSP using the ALM/ht index, but LE strength was not different in older men. However, no lower extremity strength differences were observed between SP and NSP men or women using the SMI classification. None of the SP index uniformly identified community-dwelling older adults with functional or strength deficits. CONCLUSIONS:Detection of strength deficits using SP indices alone may be gender-specific and may not reflect strength or functional decline in community-dwelling men aged 80 years or older. Given associations between lower extremity strength and physical function, strength measures remain a better predictor of physical performance than SP indices for community-dwelling older men and women.

PURPOSE/OBJECTIVE:Early ambulation and rehabilitation are recommended for patients undergoing surgical fixation of hip fracture. Gait velocity may be used as an outcome measure for these patients during acute rehabilitation. As an outcome measure, an estimate of meaningful change (responsiveness) in gait velocity for these patients, however, has not been described. The minimum detectable change (MDC) is a value that represents true change in a measure beyond that accounted for by measurement error. The purpose of this study was to quantify MDC in gait velocity as an index of responsiveness for persons in the acute stage of rehabilitation following hip fracture. METHODS:The study design was a descriptive cohort study with one repeated measure. A volunteer sample of 16 subjects over the age of 65, at a mean of 4.7 days postsurgical fixation of unilateral hip fracture, participated in the study. The study was conducted in an acute care rehabilitation practice in a large, tertiary care hospital. We measured gait velocity with the 10-meter walk test, estimated test-retest reliability with an intraclass correlation coefficient and quantified responsiveness of gait velocity as the MDC at a 95% level of confidence. RESULTS:Mean gait velocity was 15 cm/s and the test-retest reliability coefficient was equal to 0.823. The MDC in gait velocity during acute rehabilitation following surgical repair for hip fracture was 8.2 cm/s. CONCLUSIONS:Self-selected gait velocity in patients during acute rehabilitation following surgical fixation for hip fracture must improve by 8.2 cm/s or more to designate the change as being real change beyond the bounds of measurement error.