Joint acceleration during gait in relation to age.
Forty-four male and female subjects with no history of falling and whose ages ranged from 10 to 68 years participated in a series of experiments to assess movement at the joints during gait while walking in a straight line, in pivot turns and in turns of 0.33 and 0.66 m diameter. Acceleration at the joints in the forward and side-to-side direction was measured by dual-axis accelerometers placed at the ankles, knees, hips, shoulders, and on the head. Eye movement was assessed from electrodes placed on the sides of the eyes. The results of the experiments showed that for people whose age was above 40 years, significant increases in the forward-back and side-to-side movements occurred at all joints and progressively increased with age. By age 60, adverse movement of the joints as much as quadrupled in many subjects when compared to people whose age was 20-30 years. The increase in joint acceleration occurred equally in the front-back and side-to-side planes. The mechanism of the increased joint movement may be due to tendon laxness, peripheral neuropathy or loss of central control of gait due to age. Accelerometry may be a much more sensitive technique to analyze abnormalities in gait than standard video or observational gait analysis. Results are given as mean (SD) unless otherwise stated.