The influence of PAD on the kinetics and kinematics of the lower limb in the type II diabetic population

Abstract

Aim: The aim of this study was to quantify any changes in the spatio-temporal parameters of gait and kinetics in patients living with diabetes and peripheral arterial disease. Methods: Ninety participants, 60 of whom presented with PAD as well as type II diabetes mellitus were recruited. Participants were divided according to severity of PAD (mild and severe group). The remaining participants were control subjects living only with type II diabetes Mellitus. Vicon® Nexus capture system was used along with force plates in order to calculate angles for flexion/dorsiflexion and extension/plantarflexion of a) the knee joint b) the ankle joint and c) the 1st MPJ of both lower limbs. Kinetics and kinematics of the two groups were compared at three different speeds which were based upon the natural walking speed of the participant (baseline speed), increased by 5% (speed 2) and finally increased by 10% (speed 3) using a metronome. Results: PAD participants exhibited an increase in ankle joint mean angles during maximum ankle joint dorsiflexion at baseline, speed 2 and speed 3 for the left foot and at baseline and speed 2 for the right foot. A difference in mean scores resulted mostly between the normal versus mild PAD group range of motion during maximum dorsiflexion at speed 2 and speed 3 for the left foot and at all three speeds for the right foot. There was a major decrease in knee flexion resulting between the normal versus mild PAD group. As for ground reaction forces the only difference was during heel strike to midstance phase in all three speeds for left foot and at baseline and speed 3 for the right foot. This major difference varied with severity of PAD. Analysis of the gait parameters resulted in significant differences with a reduction in cadence, increased step width, stride length and stride time for the left foot and a reduced cadence opposite foot contact and stride length and an increased step time and step width for the right foot. Conclusion: Gait variability between the control group and participants living with both diabetes and peripheral arterial disease indicates that having both conditions does indeed alter patient biomechanics from the norm. This is conjectured to be secondary to the resultant oxygen deprivation of the surrounding muscles leading to tissue ischaemia. The novelty of this study was a reduction in the anterior-posterior component of the ground reaction force which may put these patients at a higher risk of falls; and an increase in angular measurements of the ankle joint which may suggest that the reduction of the ankle joint commonly revealed in diabetes may be secondary to neuropathy and not to a reduced oxygen perfusion. This research provided additional biomechanical understanding of specific patient population that contributes to improved clinical management.