The Effect of Load Carrying on Gait Kinetic and Kinematic Variables in Soldiers with Patellofemoral Pain Syndrome

Individuals suffering from patello-femoral pain syndrome (PFPS) exhibit altered gait parameters compared with healthy individuals. As soldiers carry heavy equipment, the extra load might further alter gait pattern. The aim of this study was to investigate the effect of load carrying on kinetic and kinematic variables in soldiers with PFPS compared with controls. The sample comprised 23 active-duty infantry soldiers (10 with bilateral/13 without bilateral PFPS, mean age: 20.4 (+/- 0.5) years, height 179 (+/- 5.8) cm, weight 76 (+/- 6.9) kg). The participants walked barefoot on a 10 m walkway with and without loading equipment. The equipment added 50% to each participant's body mass. Gait kinematic and kinetic variables were assessed by the VICON three-dimensional motion analysis system and two force plates. Weight carrying increased joint maximal angles, mean peak moments and double support and decreased single support and walk speed in both groups, without differences between groups (p > 0.05). The only difference between groups was in the hip adduction angle without a load (p < 0.05); no difference was observed while carrying the load. Kinematic and kinetic differences in gait were detected between weight and non-weight conditions, yet there was no effect of PFPS. Further studies with subjects performing different tasks are essential to examining the effect of PFPS and load among soldiers.