Research Report
Population: Adult
Desiree Lanzino, PT, PhD, Assistant Professor of Physical Therapy, Mayo Clinic, Department of Physical Medicine and Rehabilitation lanzino.desiree@mayo.edu
John Hollman, PT, PhD, Professor of Physical Therapy, Mayo Clinic, Department of Physical Medicine and Rehabilitation hollman.john@mayo.edu
Keywords: Prediction, ALS, Mobility
PURPOSE/HYPOTHESIS: The Amyotrophic Lateral Sclerosis Functional Rating Scale-revised (ALSFRSr) is the most prevalent disability outcome tool used for persons with ALS. A total ALSFRSr score is tabulated by combining subscores of four domains: bulbar, respiratory, fine motor, and gross motor function. While predictive of survival time, the total score lacks unidimensionality, limiting its use in predicting functional decline. Therefore, investigators have suggested that discrete domain scores may be more helpful. Most persons with ALS progress from independent functional mobility to, at a minimum, using an assistive device to mobilize. This decline is likely captured best by the gross motor subscore, which quantifies with ordinal scales the ability to turn in bed, to ambulate, and to ascend stairs. The purpose of this study was to determine if measures of timed coordination of the lower extremities or gait could be used to predict the ALSFRSr gross mobility subscore in persons with ALS.
SUBJECTS: 29
MATERIALS/METHODS: Participants were recently diagnosed with ALS and did not use an assistive device for ambulation. They were timed performing 5 repetitions of heel-on-shin, heel-to-knee/ankle, and foot taps. Fast and comfortable gait speeds were measured on a 10 meter walkway. The ALSFRSr was assessed by interview. Pearson product-moment correlation coefficients assessed relationships between the scores and timed measures. Regression analysis was used to predict the gross motor subscore.
RESULTS: All measures of timed limb performance and gait speed significantly correlated (p < .014) with the gross mobility subscore. Heel-on-shin (HS) performance of the slowest lower extremity (longest performance time) had the strongest relationship (r = -0.749, p < .001), followed by fast gait speed (r = -0.715, p < .001). The R2 value for the regression analysis for slow HS performance on the gross motor subscale was 0.561 (p < .001), whereas for fast gait speed it was 0.487 (p < .001). Combining the two measures into a hierarchical regression analysis increased the R2 value to .61; however, the increase from .56 to .61 was not statistically significant (p = .10).
CONCLUSIONS: Slow HS performance accounted for 56% of the variance in the gross motor subscore. Thus, knowing an individual’s HS performance time for the slowest lower extremity provides 56% of the information needed to accurately predict an ALSFRSr gross motor subscore. The gross motor activities of bed mobility, gait, and stair climbing all require skilled lower extremity performance, and the ability to rapidly slide the heel along the shin reflects this performance better than performance on tests of gait speed, timed foot tapping, or timing the ability to alternate the heel between the opposite knee and ankle.
CLINICAL RELEVANCE: Timing 5 repetitions of heel-on-shin performance in the slowest lower extremity in persons with ALS can be used to predict over half of the variance in the ALSFRSr gross motor subscore, reflecting overall performance on three activities important for functional independence.
Citation:
Lanzino, Desiree , PT, PhD; Hollman, John , PT, PhD. Predicting gross motor function in persons with ALS using timed lower extremity performance.. Poster Presentation. IV STEP Conference, American Physical Therapy Association, Columbus, OH, July 17, 2016. Online. https://u.osu.edu/ivstep/poster/abstracts/085_lanzino_hollman/