Continuous time series analysis on the effects of induced running fatigue on leg symmetry using kinematics and kinetic variables: Implications for knee joint injury during a countermovement jump

Abstract

This study investigates the symmetry change in joint angle and joint moment of knee joints following a Running-Induced Fatigue counter movement Jump. Twelve amateur runners volunteered to participate in the study. A prolonged running protocol was used to induce fatigue. Joint angle and moment were recorded during the push and flexion phase of the CMJ before and immediately after fatigue. Borg scale (RPE>17) and real-time heart rate monitoring (HR>90%HRmax) were used to confirm running fatigue. Symmetry function (SF) was used to assess the symmetry of the knee Angle and moment variation parameters over the entire push-off and landing phases based on time series analysis. Paired sample t-test was used to examine changes in SF before and after acute fatigue. The Angle and moment of the knee are asymmetrical in all planes (SF > 0.05), with SF ranging from 5 to 130% in angle and 5-110% in moment. There was a significant increase in knee joint angle asymmetry in the horizontal plane during the push-off and landing stage following the prolonged - Running Protocol implementation. These increases in asymmetry are mainly caused by excessive external rotation of the dominant knee joint. These findings indicate that fatigue-induced changes during CMJ may progress knee movement pattern asymmetry in the horizontal plane.

Keywords: countermovement jump; landing; running-induced fatigue; statistical parameter mapping; symmetry function.

FIGURE 1

(A) Marker-set Placement. (B) Over-ground CMJ Test and Biomechanical variable collection.

FIGURE 2

Illustration of SF degree in bilateral knee joint angle and moment during push-off stage before prolonged-running protocol for the CMJ test. Note: The red fill represents the degree of asymmetry, and the darker the color, the more asymmetry. The green fill represents full symmetry.

FIGURE 3

Illustration of SF degree in bilateral knee joint angle and moment during the landing phase before prolonged-running protocol for the CMJ test. Note: The red fill represents the degree of asymmetry, and the darker the color, the more asymmetry. The green fill represents full symmetry.

FIGURE 4

Illustration of SF degree in bilateral knee joint angle and moment during push-off phase after prolonged-running protocol for the CMJ test. Note: The red fill represents the degree of asymmetry, and the darker the color, the more asymmetry. The green fill represents full symmetry.

FIGURE 5

Illustration of SF degree in bilateral knee joint angle and moment during landing phase after prolonged-running protocol for the CMJ test. Note: The red fill represents the degree of asymmetry, and the darker the color, the more asymmetry. The green fill represents full symmetry.

FIGURE 6

Comparing the mean values of SF of knee angle and moment from all participants between fatigues (pre-fatigue; post fatigue). Note: the dotted boxes indicate a statistically significant difference, p < 0.05. Pre means Pre-fatigue, and Post means post-fatigue.