Objective: After hip fracture, walking aids are usually provided for effective muscle training and ambulation. Although the rolling walker, which is widely used nowadays, makes the move and turn easier, it can rather increase the risk of fall at downhill ramp due to unskilled control. As a result, the fear of falling increases, which can hinder proper rehabilitation and functional recovery. Therefore, we developed the world’s first “walker with non-powered automatic velocity controlled wheel”(ORBITN, SEOUL, KOREA) according to the necessity of walking aids satisfying the efficiency, safety and convenience of walking, and we aimed to verify the effect of this walker using surface electromyography (sEMG).
Methods: Seven patients who are using rolling walker after surgery on unilateral femur fracture were enrolled. We excluded patients who cannot walk with walker, already have gait disturbance caused by other causes, and have history of surgery on lower limbs. Patients walked a 5-degree downhill ramp using conventional “4-wheel rolling walker” and newly devised “walker with non-powered automatic velocity controlled wheel”(fig 1). Patient walked ramp three times for each walker and had 5-minute rest periods between each test so that previous experiment did not affect the following experiment. Surface electrodes were placed over the Tibialis anterior (TA), Gastrocnemius (GCM), Vastus medialis (VM), Biceps femoris (BF) muscles of bilateral legs, and we measured average root mean square (RMS) values per one gait cycle to quantify muscle contraction. Also we measured highest RMS value, normalized to maximum voluntary isometric contraction (MVC) data obtained in trials prior to gait acquisitions. Subjective satisfaction and fatigue degree of patients were recorded using a 10-point scale. The Wilcoxon signed-rank test was used for statistical analysis.
Results: Four patients underwent hemiarthroplasty and three patients had intramedullary nailing. Patients participated in the experiment 58.9±73.4 days after surgery. Average RMS values per one gait cycle of GCM and BF muscle in the affected side were significantly larger when the participants were using “walker with non-powered automatic velocity controlled wheel”. They reported similar safety and fatigue when using both walking aids.
Conclusions: The contraction of GCM and BF muscles were stronger when the participants were using “walker with non-powered automatic velocity controlled wheel”. This result suggests that the patients could perform more powerful toe-off with “walker with non-powered automatic velocity controlled wheel” when walking downhill slope. |
