Author(s): SICILIANO, F., BORZUOLA, R., PARRELLA, M., SCALIA, M., BORRIELLO, G., VANNOZZI, G., MACALUSO, A., Institution: UNIVERSITY OF ROME , Country: ITALY, Abstract-ID: 2776

INTRODUCTION:
The ability to produce force quickly, namely rate of force development (RFD), it is essential for activities of daily living and falls prevention. People with Multiple Sclerosis (pwMS), due to the disease-related damages to the central nervous system, generally have impaired muscle strength, leading to disability and reduced quality of life. Therefore, this study aimed to assess neuromuscular properties in pwMS and healthy controls during maximal RFD.
METHODS:
Six pwMS (mean age=42±10, female=3, EDSS=3.25±0.6) and six HC (mean age=44±10, female=3) performed 3 maximal voluntary isometric contractions (MVIC) and 12 maximal isometric RFD. For RFD test, only contractions performed “as fast and hard as possible” and with force values <75%MVC were considered valid. High-density surface electromyography (HDsEMG) was used to investigate neuromuscular properties of the Tibialis Anterior muscle of both legs. MU discharge rate (DR), recruitment threshold (RT), and force values were analysed for different RFD intervals (RFD 0-50, RFD 0-100, RFD 0-150, RFD 0-200 ms).
RESULTS:
No statistical differences for MVIC (p>0.05) as well as for RFD 0-100 (p>0.05) RFD 0-150 (p>0.05), RFD 0-200 (p>0.05). PwMS showed reduced maximal instantaneous RFD at both RFD 0-50 (p=0.029) and RFD 0-100 (p=0.021)intervals, and there was a trend for significance in RFD 0-50 (p=0.078). No statistical differences were observed for DR and RT in any interval (p>0.05).
CONCLUSION:
Despite no differences were found in neuromuscular properties, pwMS showed impaired RFD especially during the early phases (0-50, 0-100), which may be due to reduced capacity of pwMS to activate quickly the muscles. However, it is difficult to detect neuromuscular properties during such high intensity contractions and short periods.
REFERENCES
Del Vecchio et al 2019.
Borzuola et al 2023