片脚および両脚着地時の下肢関節角度と筋活動

Abstract

[Purpose] The purpose of this study was to determine the effect of two different drop landing tasks on knee kinematics and muscle activities.[Subjects] Nine healthy males participated in this study.[Methods] The subjects performed two different drop landing tasks from a box (height, 30 cm), with the dominant leg and both legs. A motion analysis system was used to obtain knee valgus and maximal flexion angles in the frontal and sagittal planes. An electromyography system was used to record muscle activities of the lower extremities during the drop landing task.[Results] Single leg landing increased the knee valgus angle, decreased the knee flexion angle, and increased the activity of the lower extremity muscles as compared to double leg landing.[Conclusion] Increased knee valgus angle and decreased knee flexion angle with single leg landing may be related to the increased risk of anterior cruciate ligament injury.

Spike-landing Motion of Elite Male Volleyball Players during Official Games

“…In any case, it is easier to maintain balance after the ‰oor contact due to having a larger base, as is the case in double-legged landings, while balance is easily lost with a single-legged base. Ankle sprain, the most common acute injury in volleyball (Verhagen et al, 2004;Bahr et al, 1994;Agel et al, 2007), may occur more severely when body balance is poor in single-legged landings, which are more risky also for ACL injury than are double-legged landings (Pappas et al, 2007;Nejishima et al, 2007;Nejishima et al, 2008). It is thought that patellar tendinopathy originates from repetitive loads exposed to the quadriceps extensor mechanism (e.g., patellar tendon) during the jump-landing sequence in volleyball (Bisseling et al, 2007).…”

“…Single-legged landings result in signiˆcantly decreased knee ‰exion at the ‰oor contact, increased knee valgus, and increased rectus femoris activity as compared to double-legged landings (Pappas et al, 2007;Nejishima et al, 2007;Nejishima et al, 2008). These characteristics have been related to increased knee ligamentous forces (Markolf et al, 2004;Shin et al, 2009) and knee injury (Boden et al, 2000;Hewett et al, 2005) in the previous literature.…”