Knee Muscular Control During Jump Landing in Multidirections.
BACKGROUND
Jump landing is a complex movement in sports. While competing and practicing, athletes frequently perform multi-planar jump landing. Anticipatory muscle activity could influence the amount of knee flexion and prepare the knee for dynamic weight bearing such as landing tasks.


OBJECTIVE
The aim of the present study was to examine knee muscle function and knee flexion excursion as athletes naturally performed multi-direction jump landing.


METHODS
Eighteen male athletes performed the jump-landing test in four directions: forward (0°), 30° diagonal, 60° diagonal, and lateral (90°). Muscles tested were vastus medialis (VM), vastus lateralis (VL), rectus femoris (RF), semitendinosus (ST), and biceps femoris (BF). A Vicon(TM) 612 workstation collected the kinematic data. An electromyography was synchronized with the Vicon(TM) Motion system to quantify dynamic muscle function. Repeated measure ANOVA was used to analyze the data.


RESULTS
Jump-landing direction significantly influenced (P < 0.05) muscle activities of VL, RF, and ST and knee flexion excursion. Jumpers landed with a trend of decreasing knee flexion excursion and ST muscle activity 100 ms before foot contact progressively from forward to lateral directions of jump landing.


CONCLUSIONS
A higher risk of knee injury might occur during lateral jump landing than forward and diagonal directions. Athletes should have more practice in jump landing in lateral direction to avoid injury. Landing technique with high knee flexion in multi-directions should be taught to jumpers for knee injury prevention.
Faculty of Physical Therapy, Mahidol University, Nakhon Pathom, Thailand.
Komsak
K
Sinsurin
Faculty of Physical Therapy, Mahidol University, Nakhon Pathom, Thailand.
Roongtiwa
R
Vachalathiti
Faculty of Physical Therapy, Mahidol University, Nakhon Pathom, Thailand.
Wattana
W
Jalayondeja
College of Sports Science and Technology, Mahidol University, Nakhon Pathom, Thailand.
Weerawat
W
Limroongreungrat
Direction; Jump Landing; Knee Flexion Excursion; Muscle Activity