This study is from a journal that isn't on the AAAS list of peer-reviewed scientific journals but the vast majority of scientific journals aren't on the list. I hesitate to include material from a journal that isn't peer-reviewed, but this one concerns a 6-minute walking test for people with MS. Most studies discuss shorter walking tests (2 minutes), and so this one dealing with a longer walk may be of interest.
From Neurorehabilitation and Neural Repair, April 13, 2016:
Prevalence of Walking-Related Motor Fatigue in Persons With Multiple Sclerosis
Decline in Walking Distance Induced by the 6-Minute Walk Test
Carmela Leone, MD1,2⇑
Deborah Severijns1
Vendula Doležalová1
Ilse Baert, PhD1
Ulrik Dalgas, MSc, PhD3
Anders Romberg, PhD4
Francois Bethoux, MD5
Benoit Gebara6
Carmen Santoyo Medina7
Heigo Maamâgi8
Kamila Rasova, PhD9
Benoît Maertens de Noordhout, MD10
Kathy Knuts11
Anders Skjerbaek12
Ellen Jensen12
Joanne M. Wagner, PhD13
Peter Feys, PhD1
1BIOMED, Hasselt University, Hasselt, Belgium
2Department of Neurosciences GF Ingrassia, University of Catania, Catania
3Department Public Health, Section of Sport Science, Aarhus University, Aarhus, Denmark
4Masku Neurological Rehabilitation Center, Masku, Finland
5Mellen Center for MS Treatment and Research, Cleveland Clinic, Cleveland, OH, USA
6National MS Center, Melsbroek, Belgium
7Hospital de Dia de Barcelona CEMCat, Barcelona, Spain
8West-Tallinn Central Hospital, Tallinn, Estonia
9Department of Rehabilitation, Third Faculty of Medicine, Charles University in Prague, Czech Republic
10Centre Neurologique et de Réadaptation Fonctionelle Fraiture-en-Condroz, Begium
11Rehabilitation and MS Center, Overpelt, Belgium
12MS Hospitals Ry&Haslev, Denmark
13Saint Louis University, St. Louis, MO, USA
Objective
To investigate the individual occurrence of walking-related motor fatigue in persons with multiple sclerosis (PwMS), according to disability level and disease phenotype. Study design. This was a cross-sectional, multinational study.
Participants
They were 208 PwMS from 11 centers with Expanded Disability Status Scale (EDSS) scores up to 6.5.
Methods
The percentage change in distance walked (distance walked index, DWI) was calculated between minute 6 and 1 (DWI6-1) of the 6-Minute Walk Test (6MWT). Its magnitude was used to classify participants into 4 subgroups: (1) DWI6-1[≥5%], (2) DWI6-1[5%; –5%], (3) DWI6-1[–5%; > –15%], and (4) DWI6-1[≤−15%].
The latter group was labeled as having walking-related motor fatigue. PwMS were stratified into 5 subgroups based on the EDSS (0-2.5, 3-4, 4.5-5.5, 6, 6.5) and 3 subgroups based on MS phenotype (relapsing remitting [RR], primary progressive [PP], and secondary progressive [SP]).
Results
The DWI6-1 was ≥5% in 16 PwMS (7.7%), between 5% and −5% in 70 PwMS (33.6%), between −5% and −15% in 58 PwMS (24%), and ≤−15% in 64 PwMS (30.8%).
The prevalence of walking-related motor fatigue (DWI6-1[≤−15%]) was significantly higher among the progressive phenotype (PP = 50% and SP = 39%; RR = 15.6%) and PwMS with higher disability level (EDSS 4.5-5.5 = 48.3%, 6 = 46.3% and 6.5 = 51.5%, compared with EDSS 0-2.5 = 7.8% and 3-4 = 16.7%; P < .05).
Stepwise multiple regression analysis indicated that EDSS, but not MS phenotype, explained a significant part of the variance in DWI6-1 (R2 = 0.086; P < .001).
Conclusion
More than one-third of PwMS showed walking-related motor fatigue during the 6MWT, with its prevalence greatest in more disabled persons (up to 51%) and in those with progressive MS phenotype (up to 50%). Identification of walking-related motor fatigue may lead to better-tailored interventions.