Effects of three gait retraining techniques in runners with patellofemoral pain.

OBJECTIVES: Analyze the effects of 3 gait retraining: forefoot landing (FFOOT), 10% step rate increase (SR10%) and forward trunk lean (FTL) on lower limb biomechanics and clinical measurements in patellofemoral pain (PFP) runners. DESIGN: Case series report. SETTINGS: Biomechanical laboratory and treadmill running. PARTICIPANTS: Eighteen recreational PFP runners randomized in 3 groups. MAIN OUTCOME MEASURES: Lower limb kinematics and muscle activation were assessed at baseline and 2-week post-training. Pain intensity and function limitation, measured by AKPS (Anterior Knee Pain Scale) and LEFS (Lower Extremity Functional Scale) assessed at baseline, post-training and 6-month follow-up. Repeated measures analysis of variance was used to compare the effects of gait retraining. RESULTS: FFOOT and FTL increased the AKPS score at post-training(P = .001; P = .008) and 6-month follow-up(P < .001; P < .001). SR10% increased the AKPS score from baseline to 6-month follow-up(P = .006). Pain and LEFS score were improved after gait retraining regardless group. FFOOT presented greater gastrocnemius(P = .037) and rectus femoris pre-activation(P = .006) at post-retraining session. Gait retraining reduced the muscle activity during stance phase and increased during the late-swing regardless group. CONCLUSION: The three techniques presented clinical benefits, improvement of pain symptoms and functional scores, was not accompanied with significant biomechanics differences that could entirely explain this clinical improvement after the intervention.

Identification of Directed Interactions in Kinematic Data during Running.

The knowledge of motion dynamics during running activity is crucial to enhance the development of rehabilitation techniques and injury prevention programs. Recent studies investigated the interaction between joints, using several analysis techniques, as cross-correlation, sensitivity analysis, among others. However, the direction of the joints pairing is still not understood. This paper proposes a study of the influence direction pattern in healthy runners by using kinematic data together with partial directed coherence, a frequency approach of Granger causality. The analysis was divided into three anatomical planes, sagittal, frontal, and transverse, and using data from ankle, knee, hip, and trunk segments. Results indicate a predominance of proximal to distal influence during running, reflecting a centralized anatomic source of movements. These findings highlight the necessity of managing proximal joints movements, in addition to motor control and core (trunk and hip) strengthening training to lumbar spine, knee, and ankle injuries prevention and rehabilitation.