Up to 40% of individuals with diabetes may experience peripheral neuropathy, and 60% of lower extremity amputations are related to suboptimal blood glucose control1,2.
Pain or loss of sensation in the feet or hands, known as peripheral neuropathy, is nerve damage that is common in individuals with type 1 diabetes (T1D) and type 2 diabetes (T2D)3,4. Its presence increases the likelihood of developing nonhealing ulcers on the feet and lower legs, as well as having a lower limb amputation3,5. Although certain precautions must be taken when physical activity is undertaken with any of these health issues, in most cases, it is possible and recommended for improving diabetes management and lowering cardiovascular and amputation risk.
Mild to moderate exercise may help prevent the onset of peripheral neuropathy6. Although physical activity likely cannot fully reverse the symptoms of peripheral neuropathy, it can prevent further loss of muscle strength and flexibility commonly experienced by individuals with distal symmetrical polyneuropathy (DSP), which typically involves both small and large nerve7. Peripheral neuropathy, with the associated decrease in sensation, carries with it an increased risk of injury, along with greater discomfort associated with painful types of neuropathy during physical activity. The individual with insensate feet may not have the pain sensation needed to recognize that an injury has occurred, and a blister or repeated trauma may go unnoticed.
Daily Foot Care
Engaging in physical activity with peripheral issues, however, does increase the risk of foot problems like ulcers. Comprehensive foot care, including daily inspection of feet and use of proper footwear, is recommended for prevention and early detection of sores or ulcers8. All individuals should closely examine their feet on a daily basis (or have someone else inspect them) to detect sores or ulcers early and follow recommendations for the use of proper footwear and appropriate socks (synthetic-cotton blends that keep feet drier).
Risk of Ulceration (or Reulceration) with Weight-Bearing Activity
Individuals without acute foot ulcers can undertake moderate weight-bearing exercise, although anyone with a foot injury or open sore or ulcer should be restricted to non-weight-bearing physical activity until the ulceration has fully healed. Prior guidelines stated that people with severe peripheral neuropathy should avoid weight-bearing activities to reduce the risk of foot ulcerations; however, moderate walking does not appear to increase the risk of foot ulcers or reulceration in individuals with peripheral neuropathy and fully healed or no ulcerations1,2. In fact, over a 12-month period, promoting weight-bearing activity in individuals with T2D did not lead to any increase in foot ulcers. In another study, individuals with T2D and peripheral neuropathy participated in walking on a treadmill, balance exercises, and strengthening exercises for the lower extremities using body-weight resistance. Close monitoring of the plantar surface of the feet indicated that the exercise program was well tolerated and with no adverse events9. Thus, weight-bearing activity can be considered following adequate assessment and counseling of patients with peripheral neuropathy2. Of note, a study also demonstrated the effectiveness of 6 months of weekly tai chi training in improving plantar sensation and balance in elderly adults and elderly adults with diabetes with a large plantar sensation loss10.
With peripheral neuropathy, sensations connected to balance and strength can be diminished. Gait can be altered, contributing to the development of orthopedic issues and a greater risk of falling. Individuals may become fearful of falling and avoid physical activity. Walking, standing, or getting out of a chair can be difficult. Furthermore, diabetes may affect gait mechanics even before the onset of peripheral neuropathy and other associated threats to mobility. By way of example, individuals with diabetes have a shorter stride length for fast walking and a longer percentage of the gait cycle with the knee in first flexion for both fast and usual walking, even without diagnosed peripheral neuropathy. They exhibit a smaller hip range of motion in the sagittal plane during usual walking, and during fast walking, they use lower ankle and higher knee generative mechanical work expenditure compared with controls11. These findings suggest that even individuals with T2D without overt peripheral neuropathy exhibit altered and less efficient gait patterns that are more apparent during walking at a maximum speed.
Additionally, walking capacity and performance decrease with the progression of foot complications. Although walking is recommended to improve fitness, it cannot be prescribed in isolation considering the increased risk of plantar injury. Walking exercise should be supplemented by partial or non-weight-bearing exercises to improve physical fitness in populations with diabetes who have, or are at high risk of developing peripheral neuropathy (Table 18.3)12. In all cases, safety must be the prime consideration of the exercise prescription.
Table 18.3. Exercise Recommendations for Peripheral Neuropathy
In summary, the development of peripheral nerve damage is common in individuals with both T1D and T2D. The most common type, DSP, includes sensorimotor symptoms reflective of both small- and large-fiber damage. Having peripheral neuropathy increases the risk of developing an ulcer and having a lower limb amputation. With proper care and preventative measures, individuals with peripheral neuropathy can benefit from regular participation in mild to moderate aerobic and resistance activities.
1. Lemaster, J. W., M. J. Mueller, G. E. Reiber, D. R. Mehr, R. W. Madsen, and V. S. Conn: Effect of weight-bearing activity on foot ulcer incidence in people with diabetic peripheral neuropathy: feet first randomized controlled trial. Phys Ther 88 (11):1385–1398, 2008
2. Lemaster, J. W., G. E. Reiber, D. G. Smith, P. J. Heagerty, and C. Wallace: Daily weight-bearing activity does not increase the risk of diabetic foot ulcers. Med Sci Sports Exerc 35 (7):1093–1099, 2003
3. Lipsky, B. A., A. R. Berendt, H. G. Deery, J. M. Embil, W. S. Joseph, A. W. Karchmer, J. L. LeFrock, D. P. Lew, J. T. Mader, C. Norden, J. S. Tan, and Infectious Diseases Society of America: Diagnosis and treatment of diabetic foot infections. Plast Reconstr Surg 117 (7 Suppl.):212S–238S, 2006
4. Smith, A. G., and J. R. Singleton: Impaired glucose tolerance and neuropathy. Neurologist 14 (1):23–29, 2008
5. Alvarsson, A., B. Sandgren, C. Wendel, M. Alvarsson, and K. Brismar: A retrospective analysis of amputation rates in diabetic patients: can lower extremity amputations be further prevented? Cardiovasc Diabetol 11 (1):18, 2012
6. Balducci, S., G. Iacobellis, L. Parisi, N. Di Biase, E. Calandriello, F. Leonetti, and F. Fallucca: Exercise training can modify the natural history of diabetic peripheral neuropathy. J Diabetes Complications 20 (4):216–223, 2003
7. Casellini, C. M., and A. I. Vinik: Clinical manifestations and current treatment options for diabetic neuropathies. Endocr Pract 13 (5):550–566, 2007
8. Singh, N., D. G. Armstrong, and B. A. Lipsky: Preventing foot ulcers in patients with diabetes. JAMA 293 (2):217–228, 2005
9. Tuttle, L. J., M. K. Hastings, and M. J. Mueller: A moderate-intensity weight-bearing exercise program for a person with type 2 diabetes and peripheral neuropathy. Phys Ther 92 (1):133–141, 2012
10.Richerson, S., and K. Rosendale: Does tai chi improve plantar sensory ability? A pilot study. Diabetes Technol Ther 9 (3):276–286, 2007
11.Ko, S. U., S. Stenholm, C. W. Chia, E. M. Simonsick, and L. Ferrucci: Gait pattern alterations in older adults associated with type 2 diabetes in the absence of peripheral neuropathy–results from the Baltimore Longitudinal Study of Aging. Gait Posture 34 (4):548–552, 2011
12.Kanade, R. V., R. W. van Deursen, K. Harding, and P. Price: Walking performance in people with diabetic neuropathy: benefits and threats. Diabetologia 49 (8):1747–1754, 2006
This article is excerpted from Chapter 18 of Exercise and Diabetes: A Clinician’s Guide to Prescribing Physical Activity, a case-study based book available through the American Diabetes Association in June 2013 and written by Dr. Sheri Colberg (find more information about the book online at www.shericolberg.com/exercise-diabetes.asp).
In addition, anyone wishing to earn free CME credits through the ADA for completing a new self-assessment program on exercise and diabetes may do so now through the ADA’s web site at http://professional.diabetes.org/ce.
Copyright © 2013 Diabetes In Control, Inc.