Abstract
Objective:
To examine the effects of orthotic intervention on unilateral postural sway after fatigue of the plantar flexor and dorsiflexor muscle groups.
Design and Setting:
Subjects were assigned to both orthotic and nonorthotic testing conditions in a counterbalanced order, then assessed for postural sway before and after isokinetic fatiguing contractions of the plantar flexors and dorsiflexors. Postural stability was measured on the motor-dominant extremity. (Motor dominance was assessed as the foot the subject used to kick a ball.)
Subjects:
Eleven active, healthy male subjects (mean age = 24 ± 2.0 years, wt = 74.5 ± 8.8 kg, ht = 180.3 ± 8.4 cm) volunteered to participate in the study.
Measurements:
Center-of-pressure postural sway was assessed via the force platforms of a Chattecx Dynamic Balance System and transformed via 4 transducers as values indicative of sway in the anterior-posterior and medial-lateral directions. The dependent measure was postural sway in centimeters. Fatigue was induced by consecutive concentric plantar flexiondorsiflexion contractions on a Kin-Com II isokinetic dynamometer.
Results:
A repeated-measures analysis of variance revealed a significant orthotic-by-test interaction. Post hoc analysis with the Tukey honestly significant difference method revealed that postural sway values of the postfatigue nonorthotic condition were significantly greater when compared with the prefatigue orthotic, prefatigue nonorthotic, and postfatigue orthotic conditions.
Conclusions:
Our results suggest that molded orthotics may be an effective means of decreasing postural sway after an isokinetic fatigue protocol. Further research is needed to determine the exact mechanism of this improvement and whether orthotics are an effective means of preventing ankle injury.
Keywords: balance, postural stability, isokinetic dynamometry
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Bates B. T., Osternig L. R., Mason B., James L. S. Foot orthotic devices to modify selected aspects of lower extremity mechanics. Am J Sports Med. 1979 Nov-Dec;7(6):338–342. doi: 10.1177/036354657900700606. [DOI] [PubMed] [Google Scholar]
- Bennell K. L., Goldie P. A. The differential effects of external ankle support on postural control. J Orthop Sports Phys Ther. 1994 Dec;20(6):287–295. doi: 10.2519/jospt.1994.20.6.287. [DOI] [PubMed] [Google Scholar]
- Guskiewicz K. M., Perrin D. H. Effect of orthotics on postural sway following inversion ankle sprain. J Orthop Sports Phys Ther. 1996 May;23(5):326–331. doi: 10.2519/jospt.1996.23.5.326. [DOI] [PubMed] [Google Scholar]
- Hoffman M., Payne V. G. The effects of proprioceptive ankle disk training on healthy subjects. J Orthop Sports Phys Ther. 1995 Feb;21(2):90–93. doi: 10.2519/jospt.1995.21.2.90. [DOI] [PubMed] [Google Scholar]
- Johnston R. B., 3rd, Howard M. E., Cawley P. W., Losse G. M. Effect of lower extremity muscular fatigue on motor control performance. Med Sci Sports Exerc. 1998 Dec;30(12):1703–1707. doi: 10.1097/00005768-199812000-00008. [DOI] [PubMed] [Google Scholar]
- Konradsen L., Ravn J. B. Prolonged peroneal reaction time in ankle instability. Int J Sports Med. 1991 Jun;12(3):290–292. doi: 10.1055/s-2007-1024683. [DOI] [PubMed] [Google Scholar]
- Lentell G., Baas B., Lopez D., McGuire L., Sarrels M., Snyder P. The contributions of proprioceptive deficits, muscle function, and anatomic laxity to functional instability of the ankle. J Orthop Sports Phys Ther. 1995 Apr;21(4):206–215. doi: 10.2519/jospt.1995.21.4.206. [DOI] [PubMed] [Google Scholar]
- Linnamo V., Häkkinen K., Komi P. V. Neuromuscular fatigue and recovery in maximal compared to explosive strength loading. Eur J Appl Physiol Occup Physiol. 1998;77(1-2):176–181. doi: 10.1007/s004210050317. [DOI] [PubMed] [Google Scholar]
- Mattacola C. G., Lebsack D. A., Perrin D. H. Intertester reliability of assessing postural sway using the chattecx balance system. J Athl Train. 1995 Sep;30(3):237–242. [PMC free article] [PubMed] [Google Scholar]
- McCulloch M. U., Brunt D., Vander Linden D. The effect of foot orthotics and gait velocity on lower limb kinematics and temporal events of stance. J Orthop Sports Phys Ther. 1993 Jan;17(1):2–10. doi: 10.2519/jospt.1993.17.1.2. [DOI] [PubMed] [Google Scholar]
- Orteza L. C., Vogelbach W. D., Denegar C. R. The effect of molded and unmolded orthotics on balance and pain while jogging following inversion ankle sprain. J Athl Train. 1992;27(1):80–84. [PMC free article] [PubMed] [Google Scholar]
- Scheuffelen C., Rapp W., Gollhofer A., Lohrer H. Orthotic devices in functional treatment of ankle sprain. Stabilizing effects during real movements. Int J Sports Med. 1993 Apr;14(3):140–149. doi: 10.1055/s-2007-1021158. [DOI] [PubMed] [Google Scholar]
- Skinner H. B., Wyatt M. P., Hodgdon J. A., Conard D. W., Barrack R. L. Effect of fatigue on joint position sense of the knee. J Orthop Res. 1986;4(1):112–118. doi: 10.1002/jor.1100040115. [DOI] [PubMed] [Google Scholar]
- Sperryn P. N., Restan L. Podiatry and the sports physician--an evaluation of orthoses. Br J Sports Med. 1983 Dec;17(4):129–134. doi: 10.1136/bjsm.17.4.129. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Stormont D. M., Morrey B. F., An K. N., Cass J. R. Stability of the loaded ankle. Relation between articular restraint and primary and secondary static restraints. Am J Sports Med. 1985 Sep-Oct;13(5):295–300. doi: 10.1177/036354658501300502. [DOI] [PubMed] [Google Scholar]
- Tropp H., Ekstrand J., Gillquist J. Stabilometry in functional instability of the ankle and its value in predicting injury. Med Sci Sports Exerc. 1984;16(1):64–66. [PubMed] [Google Scholar]