Inclination angles during cross-slope roof walking

Area of Science:

• Occupational Safety and Health
• Biomechanics
• Construction Safety

Background:

• Residential roofers face the highest fall rates in construction, leading to significant annual costs.
• Sloped roof surfaces are a primary work environment, yet postural stability on inclines is understudied.
• Inclination angles (IAs) measured via ankle markers may quantify stability during sloped work.

Purpose of the Study:

• To investigate the effect of cross-slope roof walking on anterior-posterior (AP) and medial-lateral (ML) inclination angles (IAs) in adult males.
• To determine if walking on a sloped roof alters postural stability compared to level walking.

Main Methods:

• Eleven adult males participated in level and cross-slope (6/12 pitch) roof gait sessions.
• Changes in AP and ML IAs were analyzed at heel strike (HS) and toe off (TO) for both legs separately.
• Statistical analysis compared IA differences between level and sloped conditions.

Main Results:

• Significant increases in IAs were observed on the sloped roof across most conditions (p ≤ 0.006).
• The 'lower' leg's AP IA showed no significant change (p = 0.136).
• Increased IAs suggest reduced postural stability, greater body sway, and potential for anterior-posterior slips or medial-lateral falls.

Conclusions:

• Traversing sloped roof surfaces inherently reduces postural stability in healthy workers.
• Increased inclination angles directly correlate with escalated injury and fall risk factors for roofers.
• This study highlights the need for safety interventions addressing stability on sloped work environments.