Comparison of the use of a manual stopwatch and an automatic instrument for measuring 4-m gait speed at the usual walking pace with different starting protocols in older adults

This study compared manual stopwatch-based and automatic instrument-based measurements for gait speed (GS) obtained from the individual's usual walking pace using a 4-m walking test with different starting protocols in healthy older adults.One hundred fifty-three healthy older adults aged ≥ 65 years (57 men, 96 women) participated. GS was measured using both a stopwatch and automatic timer with or without 2-m acceleration and deceleration phases. In the GS measurement using the stopwatch, the first tester stood in the middle of the timing zone (MS1) while the second walked beside the participants from the beginning line to the ending line (MS2).In the manual method, MS1 and MS2 showed similar GS for both standing and moving starts. There was no significant difference in GS measured between with the manual stopwatch and with the automatic timer in standing start. However, in the moving start protocol, GS measured with the manual stopwatch was significantly faster, by 0.05 m/s in MS1 (p 0.001) and 0.04 m/s in MS2 (p 0.001) compared to the timed GS with the automatic timer. GS measured manually using a moving start was significantly faster than that measured manually using a standing start (MS1, 0.06 m/s, 5.0%, p 0.001; MS2, 0.08 m/s, 6.8%, p 0.001); however, there was no difference between the start protocols when automatic measurements were performed (p = 0.135).The starting protocol (starting and moving start) affected the usual 4-m GS when measured using a manual stopwatch. Therefore, we suggest that careful evaluation to measure GS for functional assessment of older adults using the moving start with a manual stopwatch.