PMID- 27919485 OWN - NLM STAT- MEDLINE DCOM- 20170228 LR - 20170228 IS - 2211-0356 (Electronic) IS - 2211-0348 (Linking) VI - 10 DP - 2016 Nov TI - The Required Coefficient of Friction for evaluating gait alterations in people with Multiple Sclerosis during gait. PG - 174-178 LID - S2211-0348(16)30186-9 [pii] LID - 10.1016/j.msard.2016.10.004 [doi] AB - BACKGROUND: Required Coefficient of Friction (RCOF) is one of the most critical gait parameters associated to the occurrence of slipping in individuals affected by neurological disorders characterized by balance impairments. This study aims to calculate RCOF in people with Multiple Sclerosis (MS) on the basis of three-dimensional Gait Analysis (GA) data. METHODS: This study enrolls 22 people with MS (pwMS) who were characterized by an Expanded Disability Status Score in the range 1.5-6 and 10 healthy controls (HC). All participants underwent to three-dimensional GA from which we extracted kinematic and kinetic data (i.e. the Ground Reaction Forces, GRF, and joint moments and powers in the sagittal plane). RCOF was calculated as the ratio of the shear to normal GRF components during the stance phase of gait cycle, and normalized by the walking velocity. Thus, the following variables were extracted: first peak (named P1COF), valley (named V1COF), and second peak (named P2COF) in RCOF curve; also computating the maximum ankle dorsi-plantarflexion moment (MOMmax) and the maximum ankle joint power (PWRmax). RESULTS: Our data revealed that P2COF results are significantly lower in pwMS when compared to HC (p=0.043; Z=-2.025). In pwMS, the study found a moderate, positive correlation between V1COF and MOMmax (r=0.558; p<0.001) and a moderate, positive correlation between EDSS score and MOMmax (rho=0.622; p=0.001). While, in HC group, the study detected a moderate positive correlation between P1COF and MOM max (r=0.636; p=0.008). CONCLUSION: Friction during mid stance and push off phases is critically important to determine whether the frictional capabilities of foot/floor interface are sufficient to prevent slips in pwMS. The impaired ankle moment in MS group causes increased P2COF in comparison to HC, increasing the risk of slipping in the critical phase of transmission of the developed forces to kinematic chain. Also, the correlation analysis among RCOF values and kinetic variables describe the interplay between V1COF and MOMmax: the higher V1COF is, the higher is MOMmax; and the different correlation the study found between COF and kinetic parameters in MS and HC group highlightes the different gait patterns of the two classes of subjects. CI - Copyright A(c) 2016 Elsevier B.V. All rights reserved. FAU - Pacifici, Ilaria AU - Pacifici I AD - Department of Biomedical Sciences for Health, Universita degli Studi di Milano, Milan, Italy; Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy. Electronic address: ilaria.pacifici@polimi.it. FAU - Galli, Manuela AU - Galli M AD - Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy; "Motion analysis Lab", IRCCS San Raffaele Pisana, Rome, Italy. Electronic address: manuela.galli@polimi.it. FAU - Kleiner, Ana Francisca Rozin AU - Kleiner AF AD - Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy. Electronic address: anafrancisca.rozin@polimi.it. FAU - Corona, Federica AU - Corona F AD - Department of Mechanical, Chemical and Materials Engineering, University of Cagliari, Cagliari, Italy. Electronic address: corona.federic@gmail.com. FAU - Coghe, Giancarlo AU - Coghe G AD - Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy. Electronic address: gccoghe@gmail.com. FAU - Marongiu, Elisabetta AU - Marongiu E AD - Sport Physiology Lab, Department of Medical Sciences "Mario Aresu", University of Cagliari, Cagliari, Italy. Electronic address: elisamar84@gmail.com. FAU - Loi, Andrea AU - Loi A AD - Sport Physiology Lab, Department of Medical Sciences "Mario Aresu", University of Cagliari, Cagliari, Italy. Electronic address: loi@unica.it. FAU - Crisafulli, Antonio AU - Crisafulli A AD - Sport Physiology Lab, Department of Medical Sciences "Mario Aresu", University of Cagliari, Cagliari, Italy. Electronic address: crisaful@unica.it. FAU - Cocco, Eleonora AU - Cocco E AD - Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy. Electronic address: ecocco@unica.it. FAU - Marrosu, Maria Giovanna AU - Marrosu MG AD - Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy. Electronic address: gmarrosu@unica.it. FAU - Pau, Massimiliano AU - Pau M AD - Department of Mechanical, Chemical and Materials Engineering, University of Cagliari, Cagliari, Italy. Electronic address: massimiliano.pau@dimcm.unica.it. LA - eng PT - Journal Article PT - Observational Study DEP - 20161024 PL - Netherlands TA - Mult Scler Relat Disord JT - Multiple sclerosis and related disorders JID - 101580247 SB - IM MH - Accidental Falls MH - Adolescent MH - Adult MH - Aged MH - Ankle Joint/physiopathology MH - Biomechanical Phenomena MH - Cross-Sectional Studies MH - *Disability Evaluation MH - *Friction/physiology MH - *Gait/physiology MH - Humans MH - Middle Aged MH - *Models, Biological MH - Multiple Sclerosis/*diagnosis/*physiopathology MH - Risk MH - Young Adult OTO - NOTNLM OT - Correlation OT - Kinetic variables OT - Multiple Sclerosis (MS) OT - Required Coefficient of Friction EDAT- 2016/12/07 06:00 MHDA- 2017/03/01 06:00 CRDT- 2016/12/07 06:00 PHST- 2016/07/21 00:00 [received] PHST- 2016/10/05 00:00 [revised] PHST- 2016/10/23 00:00 [accepted] PHST- 2016/12/07 06:00 [entrez] PHST- 2016/12/07 06:00 [pubmed] PHST- 2017/03/01 06:00 [medline] AID - S2211-0348(16)30186-9 [pii] AID - 10.1016/j.msard.2016.10.004 [doi] PST - ppublish SO - Mult Scler Relat Disord. 2016 Nov;10:174-178. doi: 10.1016/j.msard.2016.10.004. Epub 2016 Oct 24.