Student Contribution  |   January 2005
Hysteresis as a Measure of Ankle Dysfunction
Author Affiliations
  • Michael L. Kuchera, DO, (PI)
    Philadelphia College of Osteopathic Medicine; Human Performance & Biomechanics Laboratory; Cambrian Science, Inc
Article Information
Emergency Medicine / Neuromusculoskeletal Disorders
Student Contribution   |   January 2005
Hysteresis as a Measure of Ankle Dysfunction
The Journal of the American Osteopathic Association, January 2005, Vol. 105, 22. doi:
The Journal of the American Osteopathic Association, January 2005, Vol. 105, 22. doi:
Introduction: By quantifying hysteresis (the retained energy of deformation), scientists and engineers better understand physical properties of many materials. For this study, a new instrument, the Ankle Torsion Monitor (AnTM), was designed to measure ankle hysteresis loops (AHL) during the application of inversion and eversion forces. A similar premise was successfully used to study low back rotational hysteresis.1 The ability to objectively document an evolving AHL spectrum during the sprain healing process and to demonstrate interventional impact on AHL would benefit treatment design choices. 
Design: This was a methodological study designed to test the ability of an AnTM protocol to document AHL changes over time and in response to different therapies using intrasubject paired ankle observations (sprained vs nonsprained repeated over time) or immediate comparison of the same ankle (pre- to post-bracing). The effect of osteopathic manipulative treatment (OMT) was also compared using intrasubject post- and pre-treatment values. 
Methods: A single investigator (MLK) palpated the lower extremities of subjects presenting with grade 1-2 supination ankle sprains. If present, articular dysfunctions (cuneiform, talocalcaneal, talocrural, fibular head, and femorotibial) were graded 1 (mild), 2 (moderate), or 3 (severe) according to AOA standards. AnTM measures (using 0-, 2-, 4-, and 6-ounce weights) were made pre- and post-application of a brace and longitudinally (every 2-3 days) in a number of cases to determine its variability on the same day and over time. AHL measurements were also made pre- and post-OMT of the sprained side and compared to the untreated AHL. 
Intervention: A single operator (MLK) performed muscle energy OMT for plantar flexion of the talocrural joint in addition to indirect joint techniques of all five joints examined. Total treatment time averaged 5 minutes. An ankle stabilizing brace (Mueller®) was employed for a portion of the study. Participants: Subjects were men and women aged 23-57 years. Those with acute ankle sprains (n=17) were included for the OMT portion of this study; additional normal subjects (n=5) allowed AHL comparison of braced and unbraced ankles. Outcome Measures: Each AHL was repeated three times with area within the loop measured by planimeter and loop extremes noting inversion-eversion range-of-motion (ROM). A cumulative somatic dysfunction load (CSDL) was determined for each lower extremity by adding all ipsilateral severity scores. Results: Bracing statistically tightened AHLs and reduced ROM. Same-day nontreated ankles (allotted 5-10 minutes rest) demonstrated no difference in ROM or in area within the AHL. On the side of the sprain, AHL measurements showed a trend (P=.137) for ROM to change between visit 1-2, but no change on the nonsprained side. 
Conclusions: AHL measurements generated by the AnTM protocol applied were shown to provide consistent, reproducible data in both normal and sprained ankles. While hysteresis measurements in this small study did not differentiate between sprained and nonsprained ankles or between those with high and low CSDL, it did demonstrate a statistical trend for AHL change over time during the healing process of a sprained ankle with a high CSDL. 
 Credit: A portion of this study was funded by the Commonwealth of Pennsylvania.
Warner MJ, Mertz JA, et al. The hysteresis loop as a model for low back motion analysis. J Am Osteopath Assoc. 1997;97:392-398.