Gait speed in relation to categories of functional ambulation after spinal cord injury.

OBJECTIVE: The aim of the present study was to assess gait speeds that distinguished between levels of functional ambulation in subjects with a spinal cord injury.
METHODS: The data of 886 spinal cord injury subjects were derived from the European Multicenter Study for Human Spinal Cord Injury and analyzed at 1, 3, 6, and 12 months after injury. The indoor and outdoor mobility items from the Spinal Cord Independence Measure were combined into 5 clinically relevant categories: (1) wheelchair-dependent, (2) supervised walker with outdoor wheelchair dependency, (3) indoor walker with outdoor wheelchair dependency, (4) walker with aid, and (5) walker without aid. The preferred walking speed that distinguished between ambulation categories was derived from the 10-meter walking test and determined using receiver operating characteristic curves.
RESULTS: The walking speed correlated well (>0.84) with the ambulation categories. The average walking speed for each category was (1) 0.01 m/s, (2) 0.34 m/s, (3) 0.57 m/s, (4) 0.88 m/s, and (5) 1.46 m/s. The average (+/- SD) speed that distinguished between the categories was 0.09 +/- 0.01 m/s (1 vs 2), 0.15 +/- 0.08 m/s (2 vs 3), 0.44 +/- 0.14 m/s (3 vs 4), and 0.70 +/- 0.13 m/s (4 vs 5). The averaged sensitivity and specificity were above 0.98 and 0.94, respectively.
CONCLUSION: In subjects with spinal cord injury, the preferred walking speed as assessed in the clinic can be used to estimate functional ambulation during daily life. The walking speed can distinguish between ambulation categories with high sensitivity and specificity.