Relationship Between Isokinetic Leg Strength and Knee Frontal Plane Projection Angle During Single Leg Squat Among Male Junior Athletes

Abstract

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.

Comparison of Knee Kinematics during Single Leg Squat across Physically Active Females with and without Dynamic Knee Valgus

“…Despite this, we manage to discover a different lower limb kinematics across physically active females with and without excessive DKV during two different SLS depths. As SLS performance is also influenced by other factors such as core strength (36), lower limb strength (37), and coordination, investigating these variables may provide a more in-depth understanding of SLS mechanics. (7,29,30).…”

The effects of hip- and ankle-focused exercise intervention on dynamic knee valgus: a systematic review

“…The minimal changes of knee valgus angle could be due to the studied population (i.e., youth athletes) who are accustomed to regular high-intensity training. Additionally, the study provided important insight on injury prevention as injury rates were often high among youth athletes ( Mail et al, 2019 ).…”

Analysis of Single Leg Squat and Single Leg Landing Performance Variability among Professional Soccer Players Across a Season

“…In previously reported studies, the variability in performance was assessed while using different functional tasks, including SLL, running, side-step cutting, and single leg jump-landing [14,15,[22][23][24][25][26]. While Brown et al [14] used SLL to evaluate variability in movements in patients with chronic ankle injury, Pollard et al [15] used the functional task of side-step cutting among soccer players after ACL reconstruction to evaluate changes in movements.…”

“…In another study by Scholtes and Salsich, SLS was evaluated for assessing movement variability among patients with patella-femoral pain [24]. In yet another series of studies, Fox et al [25] used the functional tasks of SLS and SLL to evaluate injuries among netball players, while more recently Mail et al [26] used SLL to evaluate the movement variability with reference to FPPA among a wide range of athletes including cyclists, runners, and squash players. However, all of the studies mentioned were either cross-sectional in nature and evaluated over a particular period, or performed with reference to post-injury assessment.…”