The aim of this study is to evaluate the effects of the Lumbar HAL device on core muscle activation and fatigue and compare these effects with a sham application.
This pilot study included 12 healthy participants (aged 25-35). Participants were randomized into two groups: the Lumbar HAL device group (n=6) and the sham application group (n=6). Muscle activation and fatigue were measured using surface electromyography (EMG) from the erector spinae, multifidus, quadratus lumborum, transversus abdominis, and rectus abdominis muscles. Three different fatigue protocols were applied: static loading (plank position), dynamic loading (bending and lifting movement), and core stabilization (side plank).
Static Loading Protocol (Plank Position):
Participants maintained a plank position for 3 minutes. EMG data were collected every 30 seconds to monitor muscle activation and detect fatigue based on median frequency (MF) reduction and root mean square (RMS) values.
Dynamic Loading Protocol (Bending and Lifting Movement):
Participants performed repeated bending and lifting movements for 5 minutes, with EMG recorded every 30 seconds to assess muscle activation and fatigue responses.
Side Stabilization Protocol (Side Plank Test):
Participants held a side plank position for 3 minutes, with EMG data collected at 30-second intervals to evaluate fatigue in the quadratus lumborum, external oblique, internal oblique, and transversus abdominis muscles.
EMG data were collected every 30 seconds, and muscle fatigue was assessed using median frequency (MF) reduction and root mean square (RMS) values. Repeated measures ANOVA was used for statistical analysis.
Participants in the Lumbar HAL group showed significantly higher muscle activation and lower muscle fatigue compared to the sham group. RMS values of the erector spinae, multifidus, and quadratus lumborum muscles were significantly higher in the HAL group (erector spinae: p=0.01, multifidus: p=0.03, quadratus lumborum: p=0.02). Additionally, median frequency analyses indicated that muscle fatigue started later in the HAL group. Participants in the HAL group also reported lower perceived fatigue levels compared to the sham group.
This study demonstrates that the Lumbar HAL device enhances core muscle activation and delays muscle fatigue. Data obtained from both static and dynamic fatigue protocols suggest that the Lumbar HAL may be an effective tool for improving muscle performance during rehabilitation. Additionally, participants in the HAL group displayed better postural stability compared to the sham group.
The Lumbar HAL device may play a crucial role in managing muscle fatigue by improving postural stability. Its use can be beneficial, particularly in rehabilitation protocols aimed at strengthening lumbar muscles. Future studies with larger samples are needed to investigate the long-term effects of the device and its applications in different patient groups.
Muscle Activation
Fatigue
