gastrocnemius

Objective To evaluate the effect of hyperbaric oxygen therapy (HBOT) on acute exercise-induced fatigue via electroencephalogram (EEG) signal and surface electromyography (sEMG) signal, with the aim of providing a theoretical basis and methodological reference for promoting fatigue recovery. We hypothesized that HBOT for 60 min and natural recovery would reverse the changes in the indicators related to blood flow restriction (BFR) intervention, with HBOT demonstrating a superior restorative effect. Methods College students ( n = 34) majoring in physical education were randomly assigned to an experimental group ( n = 17) or control group ( n = 17). Fatigue was induced using four sets of weight-bearing squats (30 + 15 + 15 + 15 repetitions) combined with BFR intervention set to 80% of the arterial occlusion pressure (AOP) + 20% of the one repetition maximum (1RM) of the lower limbs. The control group naturally recovered for 60 min at ambient room temperature with 1.0 absolute atmospheres (ATA) and 20.9% oxygen concentration. The experimental group received 1.3 ATA hyperbaric oxygen therapy (HBOT) for 60 min. EEG signal, sEMG signal, heart rate, blood oxygen saturation, blood lactate accumulation (LA), and the Borg Subjective Fatigue Perception Assessment Scale (RPE) were assessed before exercise, immediately after exercise, and post-intervention. Results LA, RPE, alpha and theta waves in the central area and occipital lobe; alpha waves in the parietal lobe; and average values of RMS, MF, and MPF of the musculus femoris medialis, musculus rectus femoris, and external sural muscle had time-group interaction effects. After intervention, the experimental group exhibited significantly higher α wave amplitudes (central, occipital, and parietal lobes) and MF and MPF values (vastus medialis, rectus femoris, and lateral gastrocnemius), compared with the control group ( P < 0.05). By contrast, the experimental group demonstrated significantly lower β wave amplitudes in the central and occipital lobes, lower RMS values in the vastus medialis, rectus femoris, and lateral gastrocnemius muscles, and reduced LA levels and RPE scores, compared with the control group ( P < 0.05). Conclusion EEG and sEMG signal measurements indicate that BFR intervention induces central and peripheral fatigue simultaneously. After fatigue, 1.3 ATA-HBOT accelerates recovery from both types of fatigue within 60 min. Thus, this recovery method can be used as an effective strategy to accelerate recovery from BFR intervention-induced fatigue.

matched text: “gastrocnemius”

Muscle force sharing during locomotion is influenced by the mechanical demands of movement and the contractile properties of synergistic muscles. In cats, plantarflexor muscles exhibit distinct functional specialization, with the slow-fibred soleus maintaining relatively constant force across conditions while faster muscles such as the plantaris and gastrocnemius increase force production with increasing locomotor demand. However, it remains unclear whether similar force-sharing patterns occur in larger animals with different musculoskeletal designs. Therefore, the purpose of this study was to examine force sharing between the superficial digital flexor (SDF) and medial gastrocnemius (MG) muscles during treadmill locomotion in sheep. Tendon buckle force transducers were surgically implanted on the SDF and MG tendons of seven sheep, and in vivo muscle forces were recorded during walking and trotting across different speeds and inclines. Both muscles increased force with increasing speed and incline; however, speed had a substantially greater effect than incline. The SDF consistently produced greater absolute force than the MG across all conditions, whereas the MG exhibited slightly larger relative increases in force with increasing speed. Time to peak force decreased with increasing speed in both muscles, although the SDF reached peak force later in stance than the MG across conditions. In contrast to the distinct specialization observed in cats, neither muscle displayed a relatively condition-independent, soleus-like force contribution. These findings suggest that force sharing in sheep is more distributed across synergistic muscles and may reflect the influence of musculoskeletal design, tendon compliance, and mixed fibre-type composition on muscle function in larger species.

matched text: “gastrocnemius”