Two-handed isometric pulling strengths at different floor-slope angles

Area of Science:

• Biomechanics
• Human Factors Engineering
• Ergonomics

Background:

• Understanding factors influencing maximal isometric pulling strength is vital for occupational safety and performance optimization.
• Previous research has explored various parameters, but the combined effects of exertion height and ascending floor-slope angles require further investigation.

Purpose of the Study:

• To investigate the impact of varying exertion heights (30%-90% stature) and ascending floor-slope angles (0°-15°) on maximal horizontal isometric pulling strength.
• To quantify the linear relationships between these variables and pulling strength.

Main Methods:

• Ten healthy Taiwanese men (mean age 20.4 years) participated in the study.
• Participants performed maximal horizontal isometric pulling exertions at four exertion heights and four floor-slope angles.
• Pulling strength was measured using a force transducer.

Main Results:

• Pulling strength demonstrated a linear decrease as exertion height increased.
• Pulling strength showed a linear increase with ascending floor-slope angles.
• At 90% stature, pulling strength was reduced to 35%-40% compared to 30% stature.
• A 15° floor-slope angle increased pulling strength by 127.6%-150.9% relative to a 0° slope, depending on exertion height.

Conclusions:

• Exertion height and floor-slope angle are significant linear determinants of maximal horizontal isometric pulling strength.
• These findings have implications for designing workspaces and tasks to optimize safety and performance, particularly in environments with inclined surfaces.