Gait changes over time in stance control orthosis users.

This report presents objective motion analysis measurements of 14 stance control orthoses (SCO) users during a prospective open-enrollment 6-month clinical field trial. Participants were fitted with a Dynamic Knee Brace System (DKBS) which is a novel electromechanical SCO developed by the authors. Seven of the 14 subjects that had been prescribed but did not use a KAFO at the time of enrollment were defined as novice users. Those subjects who at the time of enrollment were using a locked KAFO for ambulation were defined as experienced users. Results showed that all subjects significantly increased peak knee flexion from 49.0 +/- 15.5 degrees to 55.9 +/- 11.4 degrees between the initial and six month tests (p = 0.02). They also tended to increase peak hip flexion from 39.6 +/- 13.4 degrees to 46.0 +/- 14.5 degrees between the 3 month and 6 month tests (p = 0.09). Novice users significantly increased velocity from 74.7 +/- 19.4 cm/s to 81.2 +/- 19.0 cm/sec between the initial and 3-month tests (p = 0.005). These same users increased stride length from 109 +/- 15.3 cm to 112 +/- 16.6 cm over the same time period (p = 0.008). Experienced KAFO users, however, tended to increase velocity from 68.8 +/- 20.5 cm/s to 83.2 +/- 16.8 cm/s at 3 months (p = 0.06). This was combined with a significant increase in cadence from 76.2 +/- 14.1 steps/min to 83.9 +/- 8.3 steps/min between the initial and 3 month tests (p = 0.05). Joint kinetics showed no changes for users over the duration of the testing period. These results indicate that KAFO users make significant gains in temporodistance measures, while changes in joint kinematics take longer to develop.