Relationship of plantar-flexor peak torque and dorsiflexion range of motion to kinetic variables during walking

Program of Physical Therapy, Washington University School of Medicine, St. Louis, MO 63110, USA.

BACKGROUND AND PURPOSE. Limited ankle plantar-flexor moments and power during walking have been documented in several patient populations and are believed to contribute to gait deviations. The primary purpose of this study was to determine the relationship of plantar-flexor peak torque (PFPT) and dorsiflexion range of motion (ROM) to peak ankle moments and power during walking in a group of subjects without diabetes mellitus (DM) and in a group of subjects with DM and associated peripheral neuropathies. SUBJECTS. Nineteen subjects, 9 with DM and associated peripheral neuropathies (mean age = 58 years, SD = 14, range = 35-75 years) and 10 without DM (mean age = 57 years, SD = 11, range = 37-68 years), were evaluated. METHODS. The following data were collected on all subjects: PFPT, dorsiflexion ROM, and ankle moments and power during walking (using a two-dimensional link-segment model). Hierarchical multiple regression was used for data analysis. RESULTS. Plantar-flexor peak torque made substantial contributions to the ankle moment (40%) and ankle plantar-flexor power (53%) during walking. There also was a high correlation between PFPT and dorsiflexion ROM (r = .78) and between dorsiflexion ROM and ankle power (r = .72). CONCLUSION AND DISCUSSION. Plantar-flexor peak torque and dorsiflexion ROM are interrelated and appear to be important factors that contribute to ankle plantar-flexor moments and power during walking. This finding suggests that increasing PFPT and dorsiflexion ROM may help decrease gait deviations such as decreased step length and walking speed. When increasing PFPT is not possible, the natural occurrence of limited dorsiflexion ROM may help to maximize ankle moments during walking. Further research is needed to test whether these proposed treatment strategies can have a clinically useful effect. [Mueller MJ, Minor SD, Schaaf JA, et al. Relationship of plantar-flexor peak torque and dorsiflexion range of motion to kinetic variables during walking.

This article has been cited by other articles:

				R. L. Martin and T. G. McPoil Reliability of Ankle Goniometric Measurements: A Literature Review J Am Podiatr Med Assoc, November 1, 2005; 95(6): 564 - 572. [Abstract] [Full Text] [PDF]

				R. R. Neptune and K. Sasaki Ankle plantar flexor force production is an important determinant of the preferred walk-to-run transition speed J. Exp. Biol., March 1, 2005; 208(5): 799 - 808. [Abstract] [Full Text] [PDF]

				G. B Salsich, M. J Mueller, M. K. Hastings, D. R Sinacore, M. J Strube, and J. E Johnson Effect of Achilles Tendon Lengthening on Ankle Muscle Performance in People With Diabetes Mellitus and a Neuropathic Plantar Ulcer Physical Therapy, January 1, 2005; 85(1): 34 - 43. [Abstract] [Full Text] [PDF]

				M. J. Mueller, D. R Sinacore, M. K. Hastings, M. J. Strube, and J. E Johnson Effect of Achilles Tendon Lengthening on Neuropathic Plantar Ulcers*: A Randomized Clinical Trial J. Bone Joint Surg. Am., August 1, 2003; 85(8): 1436 - 1445. [Abstract] [Full Text] [PDF]

				S. R. SIMON, S. G. TEJWANI, D. L. WILSON, T. J. SANTNER, and N. L. DENNISTON Arthrodesis as an Early Alternative to Nonoperative Management of Charcot Arthropathy of the Diabetic Foot J. Bone Joint Surg. Am., July 1, 2000; 82(7): 939 - 939. [Abstract] [Full Text]

				G. B Salsich, M. J Mueller, and S. A Sahrmann Passive Ankle Stiffness in Subjects With Diabetes and Peripheral Neuropathy Versus an Age-Matched Comparison Group Physical Therapy, April 1, 2000; 80(4): 352 - 362. [Abstract] [Full Text] [PDF]

				R. L Gajdosik, D. W Vander Linden, and A. K Williams Influence of Age on Length and Passive Elastic Stiffness Characteristics of the Calf Muscle-Tendon Unit of Women Physical Therapy, September 1, 1999; 79(9): 827 - 838. [Abstract] [Full Text] [PDF]