Multi-Segmental Motion in Foot during Counter-Movement Jump with Toe Manipulation
Multi-Segmental Motion in Foot during Counter-Movement Jump with Toe Manipulation.
Abstract
Human toes are crucial for the vertical jumping performance. The purpose of this study is to investigate the acute effect of hallux abduction manipulation on the foot inter-segment kinematic alterations and plantar loading redistribution during the countermovement jump (CMJ). Thirteen participants were recruited to join in this experiment, for the collection of the foot inter-segment kinematics and plantar pressure data. During take-off phase, contact area presented significant increase while pressure-time integral decrease in the second metatarsal (M2), whilst third metatarsal (M3), fourth metatarsal (M4) decreased significantly in pressure-time integral with Toe-Manipulation (TM). During the landing phase, maximum force and peak pressure were smaller in big toe (BT) after hallux abduction manipulation. HXFFA (hallux-forefoot angle) showed a greater pronation after manipulation in the frontal plane (0-26% and 50-100%) with p = 0.002 and p < 0.001. In the transverse plane, the smaller adductions were found during 62-82% in take-off and 62-91% in landing (p = 0.003 and p < 0.001). A redistributed plantar loading during the landing phase from medial to lateral forefoot. However, a reduced hallux range of motion in the TM session was exhibited, comparing to Non-Toe-Manipulation (NTM). 人間の足趾は垂直跳び性能に極めて重要である。本研究の目的は、外反母趾操作がカウンタームーブメントジャンプ（CMJ）中の足部節間運動変化および足底荷重の再分配に及ぼす急性影響を検討することである。本実験では、13名の被験者を募り、足部節間運動と足底圧のデータを収集した。離陸時、第2中足骨（M2）では接触面積が有意に増加し、圧力時間積分は減少した。一方、第3中足骨（M3）、第4中足骨（M4）はToe-Manipulation（TM）により圧力時間積分が有意に減少した。着地時の最大力とピーク圧は，母趾外転位操作後の母趾で小さくなった．HXFFA（外反母趾角）は，前額面（0～26％および50～100％）において，操作後に大きなプロネーションを示し，p＝0.002およびp＜0.001であった．横面では、離陸時62-82％、着地時62-91％でより小さな内転が認められた（p＝0.003、p＜0.001）。着地時の足底荷重は、前足部内側から外側へ再配分された。しかし、TMセッションでは、Non-Toe-Manipulation（NTM）と比較して、母趾可動域の減少が見られた。 https://gyazo.com/6840d3a404125d374055834bde4cd6e3
Figure 2. The foot inter-segment angle differences during take-off in Non-Toe-Manipulation (NTM) and Toe-Manipulation (TM) sessions. Blue lines highlighted areas indicate significant differences according to spm1d with p < 0.05. Abbreviations: DF: dorsiflexion, PF: plantarflexion, Sup: supination, Pro: pronation, AD: adduction, AB: abduction, Inv: inversion, Ev: eversion, Int.: internal rotation, Ext.: external rotation.