Individuals with diabetes and peripheral neuropathy are discouraged to conduct weight bearing exercise for risk of injury due to high peak plantar pressures creating skin breakdown. However, peak plantar pressures during most weight-bearing exercises are about the same as for level walking and most non-weight bearing exercises have lower peak plantar pressures than walking, according to study results published in The Foot.
“The purpose of this study was to evaluate the in-shoe peak plantar pressures in people with diabetes and peripheral neuropathy during selected weight bearing and non-weight bearing exercises,” Kshamata Shah, BPT, of the Movement Science Program and Program in Physical Therapy at Washington University in St. Louis, said. “Understanding the plantar pressures during various exercises can help us design optimal exercise programs for people with diabetes and peripheral neuropathy who are at greater risk for unnoticed foot injury.”
Researchers recorded peak plantar pressures (PPPs) for the forefoot, midfoot and heel during level walking in 15 participants with diabetes and peripheral neuropathy and compared them with PPPs measured during weight bearing (WB) and non-weight bearing (NWB) exercises. Weight bearing exercises included treadmill walking, heel and toe raises, sit to stands, stair climbing and single leg standing, whereas NWB exercises included stationary bicycling, balance ball exercise and plantar flexion exercise. Participants measured their rate of perceived exertion on a Borg scale of six to 20. Researchers instructed participants to exercise at level 12 to 13 on the Borg scale and monitored their progress.
Compared with level walking, the mean PPP increased 13.2% during treadmill walking. However, these differences were eliminated when walking speed was used as a covariate. During heel raise exercise, the mean forefoot PPP was 27.2% higher compared to level walking. Mean forefoot PPPs decreased during toe raise exercise (–74.8%), single leg standing (–35.1%), stair climbing (–12.1%), sit to stand (–59.6%), recumbent bike (–74.3%), upright bike (–83.4%), plantar flexion exercise (–83.4%) and balance ball exercise (–79.8%) when compared with level walking.
There was no difference in mean midfoot PPPs for treadmill walking, heel raise exercise, single leg standing and stair climbing when compared with level walking. Midfoot PPPs decreased for toe raise exercise (–48.2%), sit to stand (–47.2%), recumbent bike (–57.9%), upright bike (–67.9%), plantar flexion exercise (–82.5%) and balance ball exercise (–79.3%) when compared with level walking.
Heel PPP was unchanged in the WB exercises for treadmill walking, toe raise exercise and single leg standing. Compared with level walking, the mean heel PPP was reduced for heel raise exercise (–35.8%), stair climbing (–29.2%) and sit to stand (–35.2%) in WB exercises, whereas in NWB exercises, mean heel PPPs were reduced for all exercises.
“Based on results from this study, we recommend that individuals with diabetes and peripheral neuropathy who do not have an acute ulcer or severe foot deformities may engage in WB and NWB exercises as they pose no higher stresses to the insensitive feet compared to level walking,” Shah, a doctoral candidate, told O&P Business News. “However, we recommend slow progression and close monitoring of the feet during all exercises, especially for heel raise exercises and for increases in walking speed.”
Weight bearing capacity studied
This study is part of a larger randomized control trial led by Michael J. Mueller, PT, PhD, FAPTA, of Washington University School of Medicine that examined whether individuals with diabetes and peripheral neuropathy that do not have a history of ulcers or significant foot deformity could increase their weight bearing capacity as measured by a 6-minute walk test and daily step count.
Currently in progress, the preliminary findings indicate that, overall, the weight bearing group was able to increase their weight bearing tolerance and distance on the 6-minute walk and on their daily step count.
“An important message for people with diabetes and neuropathy that do not have a history of ulcer or significant foot deformity is that they can increase their walking capacity as long as it’s done in a carefully graded fashion,” Mueller said. — by Casey Murphy
Disclosure: Mueller and Shah have no relevant financial disclosures.