Effects of running technique modification on lower limb kinematics and muscle activation in runners with and without patellofemoral pain

Abstract

It is estimated a 30-fold increase in the number of runners in the last 15 years in Brazil. This growing number of practitioners has increased all over the world. It is known that most injuries that occur as a result of this activity involves the knee joint (42,1%) and, approximately 50% of these correspond to Patellofemoral Pain (PFP). It has been hypothesized that running technique modification has a potential to reduce the demand on the knee joint, for example: increasing the trunk flexion (TFLEX), increasing 10% of the step rate (10% SR) and landing with the forefoot on the ground (FFOOT). However, no studies evaluated the effects of these running techniques on the trunk and lower limbs biomechanics in runners with and without PFP. Thus, this study will aim to: 1) evaluate the immediate effects of three running techniques (TFLEX, 10% SR, FFOOT) on the lower limb kinematics, electromyographic (EMG) activity, and subjective assessment of pain and comfort in healthy and PFP runners and; 2) verify the biomechanical and clinical effects after training in these running technique modifications. Sixty runners will be divided into four groups: healthy runners group (HG=30), runners with PFP training TFLEX group (PFP1G=10), runners with PFP training 10% SR group (PFP2G) and runners with PFP training FFOOT group (PFP3G). The trunk, hip, knee and ankle kinematics will be evaluated on a treadmill using the Qualisys and the EMG activity using the Trigno"Wireless EMG. For data analysis, a repeated-measures analysis of multivariance will be used to compare running techniques between groups and the effects of training (significance level of 5%). It is expected that the knowledge acquired with this study will assist in the development of training, treatment and prevention of lower limb injuries programs in this athletic population. (AU)