Muscle activity in the lower limbs during push-down movement with a new active-exercise apparatus for the leg

Abstract

[Purpose] Lower-limb deep vein thrombosis is a complication of orthopedic surgery. A leg-exercise apparatus named “LEX” was developed as a novel active-exercise apparatus for deep vein thrombosis prevention. Muscle activity was evaluated to assess the effectiveness of exercise with LEX in the prevention. [Subjects] Eight healthy volunteers participated in this study. [Methods] Muscle activities were determined through electromyography during exercise with LEX [LEX (+)] and during active ankle movements [LEX (−)]. The end points were peak % maximum voluntary contraction and % integrated electromyogram of rectus femoris, vastus lateralis, biceps femoris, tibialis anterior, gastrocnemius, and soleus. [Results] LEX (+) resulted in higher average values in all muscles except the tibialis anterior. Significant differences were noted in the peak of the biceps femoris and gastrocnemius and in the integrated electromyogram of the rectus femoris, vastus lateralis, gastrocnemius, and soleus. The LEX (+)/LEX (−) ratio of the peak was 2.2 for the biceps femoris and 2.0 for the gastrocnemius . The integrated electromyogram was 1.8 for the gastrocnemius, 1.5 for the rectus femoris, 1.4 for the vastus lateralis, and 1.2 for the soleus. [Conclusion] Higher muscle activity was observed with LEX (+). LEX might be a good tool for increasing lower-limb blood flow and deep vein thrombosis prevention.

A novel exercise device for venous thromboembolism prophylaxis improves venous flow in bed versus ankle movement exercises in healthy volunteers

“…In a previous study, we measured muscle activity during active combined leg exercise at a rate of 30 cycles/min, with and without LEX, in healthy participants using surface electromyography. 19 Higher magnitude muscle activity was observed for the rectus femoris, vastus lateralis, gastrocnemius, and soleus muscles, with LEX than without LEX, based on integrated electromyogram data. Another study compared femoral venous flow in healthy participants for a period of 30 min after 1 min of exercise, at a rate of 30 cycles/min, with and without LEX.…”

“…The LEX is designed to be used in the supine position, specifically for postoperative and bedridden patients. [18][19][20][21] We previously reported that a short period of active ankle exercise with the LEX improved femoral venous flow volume compared to continuous intermittent pneumatic compression. 18 The LEX makes combined leg motion possible, which involves ankle dorsiflexion/plantar flexion, ankle inversion/eversion, and knee and hip flexion/ extension.…”

Feasibility and Safety of a Novel Leg Exercise Apparatus for Venous Thromboembolism Prophylaxis After Total Joint Arthroplasty of the Lower Extremities

“…The LEX [18][19][20][21] is a novel device originally developed to perform in-bed lower extremity exercises in patients with impaired mobilization. The device has been designed so that exercises can be performed in a supine position without diminishing the positive effect of ankle plantar exion and dorsi exion on blood ow.…”

“…Therefore, we developed a novel leg exercise apparatus (LEX) to facilitate active leg movement during the early postoperative period [18][19][20][21]. In a previous study on healthy adults, we found that LEX exercising is more effective than IPC alone for improving blood ow [18].…”

Safety of Venous Thromboembolism Prophylaxis Protocol Using a Novel Leg Exercise Apparatus in Bedridden Patients due to Spinal Diseases

“…Although we recommend voluntary lower extremity exercises to prevent VTE, patients with spinal disease rarely perform leg exercises voluntarily. Therefore, we developed a novel leg exercise apparatus (LEX) that helps patients move their lower extremities voluntarily [11][12][13][14]. We found that a brief period of exercise using the LEX increased venous flow in the lower extremities compared with the continuous use of IPCD [12].…”