Effect of weight load and carrying conditions on plantar peak

Abstract

Knowledge is limited regarding the effects exerted by carrying a load on the distribution of plantar peak pressures. It is unknown whether a special technique might exist which keeps peak pressures low when carrying a load. This question is important to diabetic neuropathic patients at risk for tissue damage and pressure ulcerations and therefore with a need for minimized plantar peak pressures. The study included 19 healthy volunteers (14 M, 5 F, mean age: 34.2+/-15.2 years). They walked three times each along a 7-m walkway with an EMED pressure measurement platform under five different carrying conditions. The conditions were: carrying no load (reference), carrying a load of 20 kg in a backpack, carrying a load of 20 kg in a waistcoat, and carrying 20 kg in two bags. A fifth condition, carrying a waistcoat with a load of 10 kg only,was used to check the linearity of peak pressure and weight. Velocity and step length were measured to check the gait parameters. Peak pressures were determined in six regions: large toe, small toes,metatarsals, lateral and medial midfoot, and heel. In agreement with the literature, the reference measurements showed peak pressure to be widely independent of body weight. On the other hand, a significant increase of peak pressure was observed in a single person when a carried load was added. In the regions of the large toe,metatarsals, and heel the peak pressure increased linearly with the carried weight and amounted to 0.54, 0.76, and 0.38 N/cm(2) per kg additional load, respectively. No significant difference between the various techniques of carrying was detected. The plantar peak pressure increases with weight load,however, this is independent of the way the load is carried. No specific recommendation on the technique of carrying a load can be given in order to take care of diabetic feet.