Gait Efficiency on an Uneven Surface Is Associated with Falls and Injury in Older Subjects with a Spectrum of Lower Limb Neuromuscular Function: A Prospective Study.

OBJECTIVE: The objective of this study was to determine which gait measures on smooth and uneven surfaces predict falls and fall-related injuries in older subjects with diabetic peripheral neuropathy. DESIGN: Twenty-seven subjects (12 women) with a spectrum of peripheral nerve function ranging from normal to moderately severe diabetic peripheral neuropathy walked on smooth and uneven surfaces, with gait parameters determined by optoelectronic kinematic techniques. Falls and injuries were then determined prospectively over the following year. RESULTS: Seventeen subjects (62.9%) fell and 12 (44.4%) sustained a fall-related injury. As compared with nonfallers, the subject group reporting any fall, as well as the subject group reporting fall-related injury, demonstrated decreased speed, greater step width (SW), shorter step length (SL), and greater SW-to-SL ratio (SW:SL) on both surfaces. Uneven surface SW:SL was the strongest predictor of falls (pseudo-r = 0.65; P = 0.012) and remained so with inclusion of other relevant variables into the model. Post hoc analysis comparing injured with noninjured fallers showed no difference in any gait parameter. CONCLUSION: SW:SL on an uneven surface is the strongest predictor of falls and injuries in older subjects with a spectrum of peripheral neurologic function. Given the relationship between SW:SL and efficiency, older neuropathic patients at increased fall risk appear to sacrifice efficiency for stability on uneven surfaces.

Falls and gait characteristics among older persons with peripheral neuropathy.

OBJECTIVE: To prospectively determine the frequency and circumstances of falls in older persons with peripheral neuropathy and to identify gait characteristics on smooth and irregular surfaces associated with falls in this same population. DESIGN: This was a descriptive and observational study of a prospective group cohort. Spatial and temporal gait measures on smooth and irregular surfaces, as well as basic demographic and clinical data, were obtained in 20 older persons with peripheral neuropathy. Falls and fall-related injuries were then prospectively determined for 1 yr. RESULTS: Thirteen of 20 (65%) subjects fell, and 6 of 20 (30%) subjects sustained a fall-related injury during the year of observation. Of the 76 reported falls, 69 (90.8%) were associated with a surface abnormality (irregular or slick). Gait measures on the smooth surface did not distinguish between fall groups. On the irregular surface, however, step-time variability tended to be higher for those subjects who fell than for those who did not (89 +/- 29 vs. 64 +/- 26 msecs, respectively; P = 0.077) and for those who were injured from a fall compared with those who were not injured (101 +/- 21 vs. 71 +/- 29 msecs, respectively; P = 0.038). CONCLUSIONS: Older patients with peripheral neuropathy have a high rate of falls, and these falls are often associated with walking on irregular surfaces. Gait analysis on an irregular surface may be superior to that on a smooth surface for detecting fall risk in this patient population.

Gait analysis in a challenging environment differentiates between fallers and nonfallers among older patients with peripheral neuropathy.

OBJECTIVE: To identify differences in gait based on fall history among a group of older subjects with peripheral neuropathy (PN) in 2 environments: standard (SE) (smooth surface, normal lighting) and challenging (CE) (irregular surface, low lighting). DESIGN: Observational, case-control study of PN subjects with and without a history of falling in the previous year. SETTING: A biomechanical laboratory. PARTICIPANTS: Forty-two subjects (mean age, 64.7+/-9.8 y; 20 [47.6%] women), including 22 (52.4%) with a history of at least 1 fall in the previous year. INTERVENTION: Subjects walked in the SE and CE while kinematic data were obtained. MAIN OUTCOME MEASURES: Step width variability, step time variability, step width-to-step length ratio, step length, and step time and speed (with step length and speed normalized for height) in the SE and CE. RESULTS: In the SE, gait parameters of subjects with and without a history of falls did not differ significantly. However, in the CE, subjects with a history of falls had increased step time variability (P=.001). Moreover, significant interactions between environment and fall status were identified: in the CE, subjects with a history of falls had greater increases in step time variability (P=.010) and step width-to-step length ratio (P=.009) and greater decreases in step length (P=.007) and speed (P=.045) than did subjects with no fall history. CONCLUSIONS: Analysis of gait in the CE and adjustment to the CE from the SE effectively identified gait characteristics associated with falls in an older PN population, whereas analysis of gait in the SE did not. PN-associated gait dysfunction is more sensitively detected on an irregular rather than on a flat surface.

A comparison of gait characteristics between older women with and without peripheral neuropathy in standard and challenging environments.

OBJECTIVES: To compare gait patterns in older women with and without peripheral neuropathy (PN) in standard (smooth surface, normal lighting) and challenging environments (CE) (irregular surface, low lighting). DESIGN: Observational, controlled study of 24 subjects. SETTING: Biomechanical research laboratory. PARTICIPANTS: Twenty-four older women, 12 with PN and 12 without PN (mean age +/- standard deviation =67.1 +/- 7.9 and 70.2 +/- 4.3, respectively). MEASUREMENTS: Gait parameters and, in the 12 PN subjects, neuropathy severity. RESULTS: The CE was associated with increases in step width, step-width variability, step-width range, step width-to-step length ratio, step time and step-time variability, and decreases in step length and speed. The PN subjects demonstrated a greater step width-to-step length ratio and step time and shorter step length and slower speed than the control subjects. In adapting to the CE, the PN subjects demonstrated greater increases in step width-to-step length ratio and step-time variability and a greater decrease in step length than did the control subjects. In the standard environment, only one gait parameter correlated with PN severity, whereas in the CE, four gait parameters did so. CONCLUSION: The subjects demonstrated a gait that was slower, less efficient, and more variable temporally and in the frontal plane in the CE. Control and PN subjects demonstrated similar variability in medial-lateral step placement in the CE but at the cost of speed and efficiency for the PN subjects. Because the CE magnified gait differences between the two groups of subjects and caused gait changes in the PN subjects that correlated with PN severity, the CE may offer improved resolution for detecting gait abnormalities.

Interventions improve gait regularity in patients with peripheral neuropathy while walking on an irregular surface under low light.

OBJECTIVES: To determine which, if any, of three inexpensive interventions improve gait regularity in patients with peripheral neuropathy (PN) while walking on an irregular surface under low-light conditions. DESIGN: Observational. SETTING: University of Michigan Biomechanics Research Laboratory. PARTICIPANTS: Forty-two patients with PN (20 women), mean age+/-standard deviation=64.5+/-9.7. INTERVENTIONS: A straight cane, touch of a vertical surface, or semirigid ankle orthoses. MEASUREMENTS: Step-width variability and range, step-time variability, and speed. RESULTS: Subjects demonstrated significantly less step-width variability (mean=41.0+/-1.5, 36.9+/-1.6, 37.2+/-1.3, and 35.9+/-1.5 mm for baseline, cane, orthoses, and vertical surface, respectively; P<.0001) and range (182.7+/-7.4, 163.7+/-8.3, 164.3+/-7.4, 154.3+/-6.9 mm for baseline, cane, orthoses and vertical surface, respectively; P=.0006) with each of the interventions than under baseline conditions. Step-time variability significantly decreased with use of the orthoses and vertical surface but not the cane (P=.0001). Use of a cane, but not orthoses or vertical surface, was associated with decreased speed (0.79+/-0.03, 0.73+/-0.03, 0.79+/-0.03, 0.80+/-0.03 m/s for baseline, cane, orthoses, and vertical surface, respectively; P=.0001). CONCLUSION: Older patients with PN demonstrate improved spatial and temporal measures of gait regularity with the use of a cane, ankle orthoses, or touch of a vertical surface while walking under challenging conditions. The decreased speed and stigma associated with the cane and uncertain availability of a vertical surface suggest that the ankle orthoses may be the most practical intervention.