Change of Muscular Activity and Dynamic Stability of the Knee Joint Due to Excessive and Repetitive Jumping or Cutting by Female Athletes

Abstract

Abstract.[Purpose] Previous studies have reported that physical activity is increasingly being encouraged as an essential part of a healthy lifestyle; thus, sports and preventable injury are becoming an important public health issue. Using an isokinetic test, we evaluated muscular activities and dynamic stability of the knee joint of skilled female athletes.[Methods] The subjects were 42 females aged 24.5 ± 0.9 years old, weighing 61.5 ± 1.1 kg; they were 169.6 ± 1.3 cm in height and had a body mass index (BMI) of 18.2 ± 0.5. We used a Biodex 3 System Pro® as the isokinetic dynamometer.[Results] The extensor in the dominant leg of the jumping group showed significantly higher strength than its counterpart in the cutting group. However, knee flexors showed no significant difference between groups. Furthermore, the H:Q ratios of the jumping group (ND: 45.4 ± 2.3%, D: 45.0 ± 1.2%) and the cutting group (ND: 48.1 ± 1.9%, D: 51.5 ± 1.6%) were lower than 60%. In addition, the ratio of dominance in the jumping group was significantly lower than in the cutting group.[Conclusion] These results suggest that skilled female athletes who perform excessive and repetitive jumping actions need to be more aware of their risk of developing anterior cruciate ligament (ACL) injury, and they need a more specific therapeutic program for this injury.

Cofilin Phosphorylation Decreased by Serum-free Starvation with Low Glucose in the L6 Myoblasts

“…Skeletal muscle atrophy and joint contracture have proven to be significant orthopaedic problems in the area of physical therapy 3 , 17 , 18 ) . The skeletal muscle is the largest organ with high plasticity in the human, comprising about 50% of the total body weight.…”

Decrease of PKB/Akt Phosphorylation is Partially Mediated by SAPK/JNK Activation in Serum-free L6 Myoblasts Starved with Low Glucose

“…It has recently been reported that cofilin in eukaryotic cells binds to actin and plays a role in actin dynamics and reorganization in cast immobilization- and starvation-induced atrophy in rat gastrocnemius muscles and L6 myoblasts 20 , 21 , 22 ) . However, further systematic and scientific studies in the fields of electrotherapy, neurotherapy, hydrotherapy and others are needed to confirm the mechanisms of PKB/Akt in atrophied muscle strips and cells 23 , 24 , 25 , 26 , 27 ) ( Fig. 1D ).…”

Somatotype and body composition analysis of Korean youth soccer players according to playing position for sports physiotherapy research

“…Measurements were performed in October 2013. The participants also completed a questionnaire in an individual in-depth interview, which took 20 to 30 minutes per person 17 ) . The characteristics of the participants are shown in Table 1…”