Evaluating the Biomechanical and Ergonomic Effects of Framing Nail Guns Among Residential Carpenters: A Within-Subject Comparison of Three Commonly Used Tools

Nail guns are essential for residential framing, yet comparative evidence on how different tools influence physical workload and vibration exposure remains limited. This study evaluated the biomechanical and ergonomic implications of three framing nail guns commonly used in Australian residential construction. Nineteen carpenters completed a controlled laboratory protocol informed by field-based task analysis. Wearable sensors and motion capture quantified biomechanical and exposure differences among tool conditions. Measures included body movement, muscle activity, operating forces, vibration exposure, upper-limb demand, and overall workload. Compared with Tool A, Tool B and Tool C produced higher shoulder and wrist loading; higher relative sEMG RMS amplitude, reaching up to 161% of the Tool A reference value; and increased vibration exposure of 4.57 m/s2 and 4.98 m/s2, respectively, compared with 3.89 m/s2 for Tool A. They also showed lower comfort and balance ratings (p<0.001). These findings demonstrate distinct exposure profiles among the evaluated tool conditions; however, the fixed testing order and the absence of experimental manipulation of individual design characteristics preclude attribution of the observed differences to specific tool-design features.