The Effect of Percussive Massage on Skeletal Muscle Mitochondrial Respiration During Limb Immobilization

Skeletal muscle disuse is a common occurrence due to injury, illness, or other factors. Periods of disuse can have a profound negative impact on muscle mitochondrial function and metabolic health. Passive mechanical stimulation of skeletal muscle has demonstrated potential to improve muscle metabolic function in previous research. PURPOSE: Investigate the effect of percussive massage (PM), a trending form of muscle mechanical stimulation, on mitochondrial function and cellular metabolic pathways during a period of disuse. METHODS: 8 women and 9 men (18-35 yrs.) were randomly assigned to a control or massage group during a period of lower limb immobilization for 10 consecutive days. Two 20 min PM sessions were administered daily to the knee extensor muscles of the immobilized limb during the 10-day period. The control group laid supine for the same period of time with no PM. Mitochondrial respiration was assessed in vastus lateralis muscle biopsies using permeabilized muscle fibers with high resolution respirometry (Oroboros O2k). qRT-PCR was used to measure mRNA quantities from the isolated muscle tissue. Gene expression of CPT1A, ANT1, CD36, and ACSL1 was standardized to B2M. Data was collected pre and post intervention in both groups. RESULTS: LEAK state respiration (control: -23.7 ± 12.1%, massage: -26.3 ± 8.5%) and maximal coupled respiration (control: -21.7 ± 11.1%, massage: -20.5 ± 6.7%) decreased in both groups with no significant differences between groups. When octanoylcarnitine was used as a substrate, a significant difference in LEAK respiration (control: -22.3 ± 12.8%, massage: -2.4 ± 17.5%; p. CONCLUSION: PM attenuated the immobilization-induced decline in mitochondrial respiration in fatty acid supported respiration states. Changes in the expression of genes related to fatty acid import and mitochondrial uncoupling likely do not explain the observed attenuation of fatty-acid supported respiration with PM.