Reliability of the Soleus H-Reflex in Different Sitting Postures

Area of Science:

• Neuroscience
• Human Physiology
• Biomedical Engineering

Background:

• The Soleus (SOL) Hoffmann reflex (H-reflex) is a key measure in neuromuscular studies.
• Current recording protocols for the SOL H-reflex typically involve a sitting position.
• The reliability of SOL H-reflex measurements across different sitting postures remains largely uninvestigated.

Purpose of the Study:

• To assess the reliability of Soleus H-reflex maximum amplitude (Hmax) measurements.
• To evaluate Hmax reliability across erect, slumped, and slouched sitting postures.
• To determine the optimal number of traces and sessions for reliable Hmax recordings.

Main Methods:

• Utilized generalizability theory to analyze Hmax reliability.
• Recorded five traces of SOL Hmax from 10 healthy participants in three sitting postures across two sessions.
• Performed decision study analysis to calculate reliability coefficients and predict coefficients for varying numbers of traces and sessions.

Main Results:

• High reliability coefficients (0.943–0.980) were observed for five traces and two sessions across all postures.
• Averaging five Hmax traces within a single session yielded acceptable reliability (0.892–0.988) for all tested postures.
• Reliability remained adequate even with fewer traces or sessions, indicating robust measurement.

Conclusions:

• The Soleus Hmax can be reliably recorded during erect, slumped, and slouched sitting postures.
• Averaging five Hmax traces provides sufficient reliability for clinical and research applications.
• The findings support the use of H-reflex measurements in diverse seated conditions.