The Influence Of Forefoot Binding Force Change On Vertical Jump And EMG Of Lower Limb Variation

Background:In recent years, m etatarsophalangeal joints(MPJ), as one of the m ain four joints of lower limb have received much attention. A series of researches on anatomical structure, training method and the development of training instruments have reflected the importance of MPJ. Purpose: Most studies focused on the training of stre ngthening MPJ; however, it is important to create an effective auxiliary equipment to improve the function of MPJ. Subjects: Twelve healthy male callisthenic athletes from Ningbo University volunteered to participate in this study. All subjects had no injury and pain of lower lim b during the whole testin g procedure. Method: Subjects completed single vertical jump from a squat posture with hands on hips under three conditions. Five repeated trials were required under each condition. Kinematic and kinetic data were synchronously collected by KITLER force plate, VIC ON motion capture system and MEGA6000 EMG. Results:(1) Su bjective comfort: Pain leve l increased under strapping conditions and forefoot comfort decreased; however, HS facilitated power generation.(2) Vertical jump height: The jump height increased as strapping level increased and the difference reached to significance under HS condition( P= 0.0).(3) Joints angl es: During take-off stage, peak knee flexion under HS increased 5.9%(P=0.036) significantly compared to NS; peak ankle inversion decreased 23%(P=0.040)and external rotation decreased 27%(P=0.030)significantly under MS compared to NS. During landi ng, external rotation decreased 34%(P=0.023)significantly under MS com pared to NS.(4) R MS%: During ta ke-off, anterior tibial RM S% decreased(P=0.013)significantly under MS and bi ceps femoris RMS% d ecreased(P=0.018)significantly under HS. During landing, anterior tibial RMS% increased(P=0.011)significantly under HS condition. Conclusion: Jump performance showed to be highest under HS condition. Considering both kinetic and kinematic effects, there are drawbacks for HS com pared with MS. However, this study found no reliable strapping level standard and it is important to note that MS condition adopted in this work provide a reference for further studies.