Are contralateral pelvic drop, knee valgus and foot overpronation clinically relevant signs in injured runners?
Biomechanics Master 2 - Université Claude Bernard Lyon 1
Scientific Director: Prof Dr Jan Cabri (LIROMS)
Congratulations to Amandine Bodson who completed her Biomechanics Master's thesis.
Amandine has performed an internship during 6 months at LIROMS.
Background: The number of runners is increasing significantly each year and consequently also the number of overuse injuries. Previous research has demonstrated that kinematic parameters can be related to running injuries. Yet, we see three main kinematic parameters standing out from specific running related injuries: contralateral pelvic drop, knee valgus and foot overpronation.
Objectives: To identify whether the three aforementioned kinematic variables are clinically relevant signs of possible structural injury. Secondly, to verify if differences in the kinematics between injured and non-injured legs are prevalent. Finally, to see if there is a correlation between the injury location and the three aforementioned kinematic parameters in the injured legs of runners tested.
Design: Retrospective study
Methods: Biomechanical treadmill running analyses were conducted on 50 injured and 13 non-injured runners using a 3-dimensional motion capture system (9 cameras Miqus System, Qualisys AB, Gothenburg, Sweden). Seven kinematic variables during the gait stance phase were compared between injured and healthy runners while controlling for speed. To eliminate redundancy and increase the power of our statistical model only three variables remained relevant: peak hip adduction angle, peak knee adduction angle and peak rearfoot eversion angle.
Results: Results of the MANCOVA revealed no significant differences between the injured and non-injured runners' groups (p=0.164) for the variables controlling contralateral pelvic drop, knee valgus and foot overpronation with speed as covariate. However, significant differences between male and female participants for peak hip adduction (p=0.006) was found. Women demonstrate more hip adduction than men (mean=16.9°; SD 3.8 and 14°; SD 4.0 respectively). This difference can be explained by a larger pelvis width to femur length ratio in women than in men. In addition, running speed influenced several kinematic variables, i.e. peak hip adduction (p=0.002) and peak rearfoot eversion (p<0.001). A slower running speed was associated with reduced angle in peak hip adduction and peak rearfoot eversion The results of the paired sample T-test revealed that the injured and non-injured legs in the injured running population showed no significant differences with peak hip adduction (p=0.372), peak knee adduction (p=0.343) and peak rearfoot eversion (p=0.804) angles at mid-stance. As for the multiple logistic regression analysis, the relationship between the set of variables and injury location showed no significant relationship for foot (R2=0.043; p=0.535), lower leg (R2=0.190; p=0.017, knee (R2=0.038; p=0.465), or hip (R2=0.149; p=0.109).
Conclusion: Contralateral pelvic drop, knee valgus and foot overpronation kinematic parameters are influenced by the population, running speed and injury location. For future research, a subclassification of the kinematic representation of each RRI could help clinician in their clinical reasoning process when evaluating runners and could target the intervention strategy development.