RELATIONSHIP BETWEEN ISOKINETIC LEG STRENGTH AND KNEE FRONTAL PLANE PROJECTION ANGLE DURING SINGLE LEG SQUAT AMONG MALE JUNIOR ATHLETES

@#Background: Those with increased dynamic knee valgus are vulnerable to increased risk of non-contact knee injuries. However, studies on the top down kinetic chain of lower limb mechanics during dynamic motions such as single leg squat (SLS) among trained males were scarce. Objective: The objective of the study was to evaluate the relationship between isokinetic hip and knee strength and frontal plane projection angle (FPPA) of the knee joint during SLS. Methods: Thirty-two male junior athletes (twelve cyclists, ten runners and ten squash players) were screened for excessive dynamic knee valgus (DKV) prior to participation. Only those within the normal value of DKV were included. Their hip and knee isokinetic strength in sagittal plane were evaluated at 60º/s of angular velocity for both legs using dynamometer. Two dimensional knee FPPA was evaluated during SLS at 60º of knee flexion. Pearson correlation was evaluated between knee FPPA during SLS and isokinetic leg strength. Results: Correlations between knee FPPA and hip and knee isokinetic strength were not statistically significant except between knee flexion peak torque/body weight (r = -0.35, p = 0.05) and hamstring to quadriceps ratio (r = -0.39, p = 0.03) of non-dominant leg. Conclusions:Isokinetic hip and knee strength and knee FPPA during SLS was correlated only for non-dominant leg during SLS among male junior athletes. DKV during SLS may be reduced through strengthening the muscles around hip and knee joints.

Anaerobic capacity of physically active eumenorrheic females at mid-luteal and mid-follicular phases of ovarian cycle.

AIM: The present study was undertaken to evaluate the anaerobic capacity in repeated sprint cycling bouts during mid-luteal (ML) and mid-follicular (MF) phases of ovarian cycle. METHODS: Twelve physically active females aged 22.41±1.68 years, with normal regular menstrual cycle and VO2max of 34.92±4.85 mL·kg-1·min-1 volunteered as subjects in this study. The menstrual phases were verified through daily basal body temperature recording and serum progesterone analysis. Anaerobic capacity was quantified by measuring maximal accumulated oxygen deficit (MAOD). In this study, MAOD was measured following well established method. Initially, the VO2max of the subjects was measured following a graded exercise protocol on a cycle ergometer. On separate days, the subjects performed sub-maximal cycling exercise at 50%, 60%, 70% and 80% of VO2max for 10 minutes. The linear regression determined from the sub-maximal VO2-power relationship was used to estimate the supra-maximal power output at 120% VO2max. The subjects performed repeated sprint cycling for 3 times at 120% of VO2max with 20 minutes rest between consecutive sprints during MF and ML phases. RESULTS: Results indicated there was no significant difference in maximal accumulated oxygen deficit (MAOD) and sprint performance between MF and ML phases in repeated sprint cycling. Serum progesterone was significantly lower in luteal phase after repeated sprints. CONCLUSION: Hence, it is concluded that the anaerobic capacity is unaffected by ovarian phases in women with regular menstrual cycle. Lower serum progesterone after repeated sprints might be due to the repeated anaerobic activity.