RESUMEN
Due to its dynamic nature, lower limb injuries are common in badminton. Overuse injuries of the knee, including tendon related conditions, are the most common. During jumping and landing, force transference and dissipation through the trunk is required, with the trunk muscles playing a vital role. However, the relationship between knee pain and the ability to voluntarily contract the trunk muscles has not yet been explored in badminton players. A cross-sectional study of Australian badminton players was therefore conducted. Players performed a single leg decline squat to identify those with knee pain. Ultrasound imaging was used to image and measure the size of the multifidus and quadratus lumborum, and the ability to contract the abdominal and multifidus muscles. Voluntary contraction of the trunk muscles was conducted with the subjects lying down. Independent samples T-Tests were performed to test for between group differences. Badminton players with knee pain had larger quadratus lumborum muscles and demonstrated a greater change in muscle thickness from the rested to contracted state. While we cannot comment on causation or direction, over co-contraction of trunk muscles has been shown in other studies to be associated with increased ground reaction forces on landing. Motor control training has been successfully used in other conditions to modify trunk muscle recruitment patterns and may therefore potentially represent a useful approach for badminton players.
RESUMEN
Prolonged bed rest and inactivity is known to cause muscular atrophy with previous research indicating that muscles involved in joint stabilisation are more susceptible. The anterior hip muscles are important for hip joint function and stability but little is known about the effects of prolonged inactivity on their function. This study investigated the effect of prolonged bed rest on the size of the anterior hip muscles and their pattern of recovery. The effect of resistive vibration exercise (RVE) as a countermeasure to muscle atrophy was also investigated. 12 male participants, randomly assigned to either a control or an exercise group, underwent 8 weeks of bed rest with 6 months follow-up. Changes in muscle cross-sectional area (CSA) of the iliacus, psoas, iliopsoas, sartorius and rectus femoris muscles were measured by magnetic resonance imaging at regular intervals during bed rest and recovery phases. CSAs of iliopsoas and sartorius decreased at the hip joint (p<0.05) during bed rest but iliacus, psoas, and rectus femoris CSAs were unchanged (p>0.05). No significant difference was found between the two groups for all muscles (all p>0.1), suggesting inefficacy of the countermeasure in this sample. These findings suggest that prolonged bed rest can result in the atrophy of specific muscles across the hip joint which may affect its stability and function.