The impact of muscle strength and balance on gait performance in multiple sclerosis: effects of functional balance or progressive resistance training

Publikation: Ph.d. afhandling/ kandidat/ diplomPh.d. afhandlingForskningpeer review

Abstract

Background: Gait impairment is one of the main complaints in persons with multiple sclerosis (PwMS). Muscle strength and balance are two interacting prerequisites that are both associated with gait performance and subsequently recommended as targets in MS gait rehabilitation. However, their relative contribution to gait performance has only been sparsely studied. Furthermore, the effectiveness of balance and motor control training (BMCT) and progressive resistance training (PRT) of the lower extremities on gait performance has not
previously been investigated in the same study. In addition, the reliability of the Six Spot Step Test (SSST) – a gait outcome that in addition to maximal walking also challenges balance and coordination - is not known in MS, despite the obvious relevance to gait interventions.
Objectives: The primary purposes of the thesis were in PwMS 1) to investigate the relative association of lower body muscle strength and balance to gait performance and 2) to investigate the effectiveness of BMCT and PRT in improving gait performance and fatigue impact. A Secondary purpose was to determine the reliability of the SSST.
Methods: A randomized controlled multi-center study comparing BMCT, PRT, and a control group (CON) was conducted. Participants were tested at Aarhus University, while the interventions were delivered as supervised group training at physiotherapy clinics. Associations of muscle strength and balance to gait performance were determined from linear regression analyses on baseline data (n=90). Effects of the interventions were determined from mixed effect model analyses in the fraction of patients that had pronounced gait impairments
at baseline and were enrolled in the RCT part of the study (n=71). Outcomes included fast walking speed (Timed 25-Foot Walk (T25FW), Six Minute Walk (6MW)), complex walking (SSST), and fatigue impact (Modified Fatigue Impact Scale). In addition, a reliability study (n=38) that determined the day-to-day agreement on the SSST was conducted to assist interpretation of the RCT. Limits of agreement were estimated from Bland-Altman analyses and reliability from intra-class correlations.
Results: Lower body muscle strength and balance showed comparable associations with fast walking (T25FW and 6MW), while only balance was associated with complex walking (SSST). Post-hoc analyses suggested a stronger association between muscle strength and gait speed in less impaired PwMS. BMCT but not PRT improved gait performance (T25FW and SSST) significantly when compared to CON, while both BMCT and PRT reduced fatigue impact
significantly. The SSST was reliable and showed limits of agreement that were comparable to other tests of functional performance.
Interpretation: Lower body muscle strength and balance are associated with gait performance, but the improvement of functional balance and coordination seems to have a greater impact on functional performance compared to improvement in muscle strength. This applies for both fast and complex walking and underlines the importance of specificity and subsequently a functional approach in rehabilitation.
OriginalsprogEngelsk
KvalifikationCand.scient.
Bevilgende institution
  • Aarhus Universitet
Vejledere/rådgivere
  • Dalgas, Ulrik, Vejleder, Ekstern person
  • Brincks, John, Rådgiver
  • Cattaneo, Davide, Rådgiver, Ekstern person
Bevillingsdato25 okt. 2019
UdgivelsesstedAarhus Universitet
StatusUdgivet - 25 okt. 2019

Emneord

  • Sygdom, sundhedsvidenskab og sygepleje

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