• Journal of Institute of Control, Robotics and Systems
• /
• v.16 no.10
• /
• pp.948-956
• /
• 2010

The purpose of this study was to test the effectiveness of a prototype KAFO (Knee-Ankle-Foot Orthosis) powered by two artificial pneumatic muscles during walking. We had previously built powered AFO (Ankle-Foot Orthosis) and KO (Knee Orthosis) and used it effectively in studies on assistance of plantaflexion and knee extension motion. Extending the previous study to a KAFO presented additional challenges related to the assistance of gait motion for rehabilitation training. Five healthy males were performed gait motion on treadmill wearing KAFO equipped with artificial pneumatic muscles to power ankle plantaflexion and knee extension. Subjects walked on treadmill at 1.5 km/h under four conditions without extensive practice: 1) without wearing KAFO, 2) wearing KAFO with artificial muscles turned off, 3) wearing KAFO powered only in plantaflexion under feedforward control, and 4) wearing KAFO powered both in plantaflexion and knee extension under feedforward control. We collected surface electromyography, foot pressure and kinematics of ankle and knee joint. The experimental result showed that a muscular strength of wearing KAFO powered plnatarfexion and knee extension under feedforward control was measured to be lower due to pneumatic assistance and foot pressure of wearing KAFO powered plnatarfexion and knee extension under feedforward control was measured to be greater due to power assistance. In the result of motion analysis, the ankle angle of powered KAFO in terminal stance phase was found a peak value toward plantaflexion and there were difference of maximum knee flexion range among condition 2, 3 and 4 in mid-swing phase. The current orthosis design provided plantaflexion torque of ankle jonit in terminal stance phase and knee extension torque of knee joint in mid-swing phase.

• Journal of Korean Foot and Ankle Society
• /
• v.6 no.2
• /
• pp.181-189
• /
• 2002

Purpose: We try to evaluate the functional outcomes of the ankle with isokinetic plantaflexion torque for acute achilles tendon rupture cases those treated by primary repair with the Krackow suture technique and early rehabilization. Materials and Method: The authors studied retrospectively, 15 patients of acute achilles tendon rupture treated and followed over six months, from July 1997 to May 2001. There were 12 men and 3 women, and mean age was 39.6year. The repair method of ruptured tendon was single or double Krackow suture technique. One week(5days-2weeks) after operation, early ROM with ankle-foot orthosis was started. We used Arner-Lindholm Scale for the clinical evaluation and analyzed patient's satisfaction and subjective strength deficit. We analyzed the dorsiflexion peak torque and plantarflexion peak torque of the ankle statistically with strength test with Cybex dynamometer. Result: In clinical results, we had 11 excellent cases(73%) and 3 good cases(20%). In patients satisfaction degree, 11 excellent cases(66.6%), 3 good cases(20%) and 2 fair cases(13.4%). And in strength deficit, 3 none deficit (20%), 9 minimal deficit(60%). We evaluated the isokinetic plantar flexion torque in 3months or 6months after operation. After 3 months, isokinetic test showed the mean functional deficits, 32% and 25% at $30^{\circ}$ and $120^{\circ}/sec$, in 7 cases(46.6%) of 15 cases respectively. After 6 months, the mean deficits were in 21%, 24% at 30. and $120^{\circ}/sec$, respectively. At 3 and 6 months' follow up, absolute value of isokinetic test showed increase of 25. 31bs to 421bs and 19.61bs to 271bs at $30^{\circ}$ and $120^{\circ}/sec$, respectively. Conclusion: We had good result for acute achilles tendon rupture treated by Krakow suture technique and early range of motion exercise of the ankle. After 6 months, strength deficit was 21% in all of cases but were able to return pre-injured state. This study shows Krakow suture technique was recommended method for primary repair and early rehabilization of achilles tendon ruptue.