Muscle Activation

The aim of this study is to evaluate whether surface electrodes can record physiological muscle activity as accurately as the gold-standard needle electrodes in the tibialis anterior muscle using a diagnostic EMG device The aim of this pilot study is to investigate whether muscle activation data, similar to surface electromyography (SEMG), can be obtained by adjusting the measurement and recording parameters of standard Electroneuromyography (EMG) devices used routinely for diagnostic purposes. Although SEMG is considered the gold standard for the objective assessment of muscle activation, its clinical use in our country is limited due to the high cost of specialized hardware and software. In contrast, diagnostic EMG devices are widely available in many healthcare institutions. The research will be conducted on 30 healthy volunteers between the ages of 20 and 60. Participants will undergo lower extremity nerve conduction studies, reflex response measurements, and muscle activation assessments during voluntary isometric contractions of the m. tibialis anterior. Muscle activation will be recorded using the diagnostic EMG device via surface (adhesive and Ag/AgCl coated) electrodes and needle electrodes. The acquired EMG signals will be analyzed in terms of RMS (Root Mean Square), amplitude, and frequency parameters. The procedures performed within the scope of this study are standard practices carried out during routine EMG examinations. The only additional procedure specific to this research is the repetition of muscle activation measurements using different electrode systems. There is no invasive procedure involved in the surface electrode applications, and the needle electrode application will be performed exactly as it is in routine EMG tests. No serious risks are anticipated; rarely, mild pain, redness, or minor bleeding at the needle insertion site may occur. Through this study, diagnostic EMG devices could be utilized more effectively in rehabilitation and treatment monitoring. It is intended to contribute to the reduction of invasive procedures and to establish a scientific foundation for clinical applications regarding the objective evaluation of muscle activation.

This single-visit, laboratory study will quantify latissimus dorsi activation during standardized band/body-weight exercises commonly used in rehabilitation (e.g., standing bent-over row, inferior glide, seated press-up, body-lifting). Healthy, physically active adults (18-40 y; Tegner ≥5) will perform three repetitions per exercise with metronome-paced phases (≈3 s concentric, 3 s isometric, 3 s eccentric), 5-s rest between repetitions and 2-min between exercises; load will be individualized to reach OMNI RPE 6-8. Surface EMG (TeleMyo DTS; Noraxon) will be recorded from the latissimus dorsi (medial and lateral) and selected synergists (teres major, infraspinatus, posterior deltoid, triceps); electrode placement will follow SENIAM recommendations. Signals will be band-pass filtered (20-500 Hz), rectified, RMS-smoothed with a 100-ms window, and normalized to %MVIC using standardized MVC tests; exercise/MVC order will be randomized to limit bias. The primary outcome is mean normalized EMG amplitude per exercise; secondary outcomes include peak amplitude and categorical activation levels (low ≤20% MVIC, moderate 21-40%, high 41-60%, very high \>60%). The study involves minimal risk (possible mild skin irritation under electrodes and transient post-exercise fatigue).

This observational, cross-sectional laboratory study at Hacettepe University will examine surface EMG activation of the latissimus dorsi during resisted, dynamic shoulder extension performed at three shoulder flexion angles (30°,60°, 90°, 120°). The primary objective is to quantify latissimus dorsi activation and to determine how elevation angle influences activation; secondary analyses compare synergists.

This randomized controlled trial aims to investigate the effects of Schroth exercises on scapular muscle activation in children with thoracic hyperkyphosis. A total of 56 participants will be randomly assigned to either the Schroth exercise group or the control group receiving postural education. The intervention group will complete an 8-week supervised Schroth program focusing on three-dimensional correction, rotational breathing, and postural awareness. Primary outcome is scapular muscle activation measured by surface EMG. Secondary outcomes include muscle strength, scapular endurance, kyphotic appearance, posture, and pain. The results will guide clinical management and preventive strategies for children with postural thoracic hyperkyphosis.