被動髖關節穿戴裝置的開發與網球防守型開放式站姿正拍阻力訓練的應用

Abstract

網球為常見的球類運動之一，由於須即時追蹤球路以擊球，因此必須配合大的髖關節角度以做出大跨步，但也因此導致髖關節的受傷風險提升。其中，防守型開放式站姿正拍的髖關節角度較大，在跑動所產生的衝量下更容易做出過大的角度，而肌力不足以負荷的部分易造成髖關節韌帶拉傷。因此本研究為針對防守型開放式站姿正拍之髖關節動作進行阻力訓練以減低賽事期間的受傷風險，開發一穿戴式髖關節阻力訓練裝置並探討其對髖關節活動與相關肌肉激發的影響。 為了分析防守型開放式站姿正拍的動作特徵，本研究將防守型開放式站姿正拍分為三個動作區間，並利用光學動作追蹤系統量測髖關節角度以及肌電訊號系統量測臀中肌、闊筋膜張肌、縫匠肌、臀大肌之激發。結果顯示在右腳踩地到擊球瞬間的區間會產生較日常生活大的髖關節外展與內旋且臀中肌、闊筋膜張肌、縫匠肌、臀大肌之激發程度皆偏高，因此裝置的設計著重在提供髖關節大外展與大內旋的阻力。 一般髖關節外骨骼式設計中針對內外旋的自由度常因為無法對正內旋-外旋旋轉軸而影響動作的流暢性，因此，本研究利用髖關節球接頭的特性提出一個以球面機構為基礎的三自由度髖關節外骨骼設計，以股骨頭球心做為三個旋轉接頭的轉軸相交中心，並在提供內外展及內外旋自由度的兩個旋轉接頭內設計一扭轉阻力機構，整體結構可根據人體尺寸進行調整。 為探討此穿戴式髖關節阻力訓練裝置對防守型開放式站姿正拍的影響，本研究比較五位業餘網球愛好者在未穿戴裝置、穿戴裝置但無扭轉阻力、與穿戴裝置且有扭轉阻力的條件下進行十次防守型開放式站姿正拍擊球，並以光學動作追蹤系統以及肌電訊號系統截取運動特徵以分析裝置所造成的變化。實驗結果發現在三個動作區間中，訓練目標之髖關節角度及肌肉激發程度均無顯著不同，表示髖關節的阻力訓練效果並不顯著。可能原因為裝置軟性穿戴的傳遞損失、受試者動作不精確、扭力彈簧力矩不足、受試者人數太少等原因導致。因此未來可針對裝置的能量傳遞進行改良並增加受試者人數。

Tennis is one of the most common sports. Large hip joint angles are required when chasing the ball but also increase the risk of hip injuries. In particular, the defensive open stance involves larger hip angles than other stances. Excessive angles under running impact can lead to hip ligament strains due to insufficient muscle strength. This study focuses on resistance training for the hip joint in a defensive open stance forehand to reduce risks of injury during matches. We developed a wearable hip device for resistance training and investigated its effects on hip movements and related muscle activation. To characterize the motion of the defensive open stance forehand, this study divided the motion into three phases by using an optical motion tracking system to measure the right hip joint angle and an electromyography (EMG) system to measure the activation of the gluteus medius, tensor fasciae latae, sartorius, and gluteus maximus. The results showed that during the phase from right foot strike to ball hitting, there were larger hip abduction and internal rotation angles compared to everyday activities, and the activation levels of the gluteus medius, tensor fasciae latae, sartorius, and gluteus maximus were all high. Therefore, the device design focused on providing resistance for large hip abduction and internal rotation. The study proposes a novel approach to hip exoskeleton design. Traditionally, such designs often affect motion fluidity due to misalignment of the internal-external rotation axis. To overcome this, the study introduces a spherical mechanism-based three-degree-of-freedom hip exoskeleton design. This design utilizes the characteristics of the hip joint ball socket, with the femoral head's ball center serving as the intersection of the three rotation joints. A torsion resistance mechanism is integrated into the two rotational joints that provide internal-external abduction and rotation. The overall structure is adjustable according to human body dimensions, making it a promising solution for improving motion fluidity in hip exoskeletons. The study's investigation into the impact of the wearable hip resistance training device on the defensive open stance forehand yielded interesting results. Five amateur tennis enthusiasts were compared under three conditions: without the device, with the device but without torsion resistance, and with the device and torsion resistance. Each participant performed ten defensive open stance forehands, and their motion characteristics were analyzed. The experimental results showed no significant differences in hip angles and muscle activation levels across the three phases, indicating that the hip resistance training effect was not significant. However, it's important to note that these findings may be influenced by factors such as the soft wearable device's transmission loss, imprecise participant movements, insufficient torque from the torsion springs, and the small number of participants. These potential limitations suggest avenues for future research and improvement of the device.