Energy cost and forces acting on the poles during Nordic Walking in different surface conditions

Thirteen women of average age, weight and height took part in the study.
Each participant performed one 18-minute field test consisting of three units of 1,200 m each on an artificial treadmill, grass and concrete in the athletics hall of the German Sports University in Cologne. The order of the surfaces was chosen randomly. Since the impulse that is generated by the poles on the body is identical between the different surfaces, the main regulator of propulsion must be the musculature of the lower limbs. Upper limb work appears to be a luxury effort for Nordic walkers; with proper technique, it can also involve a balance control mechanism rather than an active contribution to forward propulsion. Our data on pole reaction forces therefore do not reflect the findings on lower limb loading of Dixon, who measured the greatest amount of mechanical impact absorption on soft surfaces for the lower limbs. On the other hand, Glasheen and McMahon showed that the metabolic costs and force generation are due to the different stiffness capacities of the upper and lower limbs, which are four to five times higher for running on hands compared to running on the limbs of running quads. Thus, the results obtained from the lower limbs cannot be transferred directly to the upper limbs due to the marked differences in limb structure.