Bone changes in the lower limbs from participation in an FES rowing exercise program implemented within two years after traumatic spinal cord injury

Abstract

Objective: To determine the effect of a functional electrical stimulation (FES) rowing program on bone mineral density (BMD) when implemented within two years after SCI.

Design: Prospective.

Setting: Health Care Facility.

Participants: Convenience sample; four adults with recent (<2 years) traumatic, motor complete SCI (C7-T12 AIS A-B).

Intervention: A 90-session FES rowing exercise program; participants attended 30-minute FES training sessions approximately three times each week for the duration of their participation.

Outcome Measures: BMD in the distal femur and tibia were measured using peripheral Quantitative Computed Tomography (pQCT) at enrollment (T₀) and after 30 (T₁), 60 (T₂), and 90 (T₃) sessions. Bone stimulus was calculated for each rower at each time point using the average number of weekly loading cycles, peak foot reaction force, and bone mineral content from the previous time point. A regression analysis was used to determine the relationship between calculated bone stimulus and change in femoral trabecular BMD between time points.

Results: Trabecular BMD in the femur and tibia decreased for all participants in T_0-1, but the rate of loss slowed or reversed between T_1-2, with little-to-no bone loss for most participants during T_2-3. The calculated bone stimulus was significantly correlated with change in femoral trabecular BMD (P = 0.016; R²= 0.458).

Conclusion: Consistent participation in an FES rowing program provides sufficient forces and loading cycles to reduce or reverse expected bone loss at the distal femur and tibia, at least temporarily, in some individuals within two years after SCI.

Trial Registration: NCT02008149.

Keywords:

• Spinal cord injury
• Paralysis
• Functional electrical stimulation
• Bone density
• Rowing
• pQCT
• FES rowing
• SCI
• FES

Acknowledgements

We are very grateful for the help with recruitment provided by Dr. James Crew, Dr. Steve McKenna, and Carrie Heinrichson at the Santa Clara Valley Medical Center, and by the Bay Area & Western Chapter of the PVA. Finally, we especially want to thank the individuals with SCI who participated in this study.

Disclaimer statements

Contributors None.

Funding This work was supported by the United States Department of Veterans Affairs, Rehabilitation Research and Development Service [grant number I21 RX001410].

Declaration of interest None.

Conflicts of interest The authors report no conflicts of interest.

ORCID

Rebecca L. Lambach http://orcid.org/0000-0001-7977-7557

Gary S. Beaupre http://orcid.org/0000-0002-6211-7621

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.