Situational factors that influence overreaching on a ladder during a gutter clearing task among older adults

Ladder Use Ability, Behavior and Exposure by Age and Gender

This study aimed to quantify and compare ladder use ability and behavior in younger and older men and women from three ladder use behavior experiments. The experimental tasks comprised (1) changing a lightbulb on a household stepladder under two cognitive demands (single and dual task), (2) clearing a simulated roof gutter on a straight ladder and (3) querying ladder choice in different exigency scenarios. Ladder use ability and behavior data were captured from recorded time, performance, motion capture and user choice data. In addition, this study surveyed ladder use frequency and habitual behaviors. The experimental findings indicate that older adults require more time to complete ladder tasks; younger adults display riskier ladder use behaviors; men and women display similar ladder use ability; and men are more willing to climb riskier ladders. The survey found older adults to report more frequent ladder use than younger adults, and men use straight ladders more frequently than women. These results suggest that the reported higher ladder fall rates experienced by older adults and men are linked to increased ladder use exposure and riskier ladder choice. This knowledge can help guide population-specific interventions to reduce ladder falls in both young and older people.

Correlations between reach, lean and ladder tipping risk

Overreaching is a common cause of ladder falls, which occur frequently among older adults in the domestic setting. Reaching and body leaning during ladder use likely influence the climber-ladder combined center of mass and subsequently center of pressure (COP) position (location of the resultant force acting at the base of the ladder). The relationship between these variables has not been quantified, but is warranted to assess ladder tipping risk due to overreaching (i.e. COP traveling outside the ladder's base of support). This study investigated the relationships between participant maximum reach (hand position), trunk lean, and COP during ladder use to improve assessment of ladder tipping risk. Older adults (n = 104) were asked to perform a simulated roof gutter clearing task while standing on a straight ladder. Each participant reached laterally to clear tennis balls from a gutter. Maximum reach, trunk lean, and COP were captured during the clearing attempt. COPwas positively correlated withmaximum reach(p < 0.001; r = 0.74) and trunk lean (p < 0.001; r = 0.85). Maximum reach was positively correlated with trunk lean (p < 0.001; r = 0.89). The relationship between trunk lean and COP was stronger than that between maximum reach and COP, denoting the importance of body positioning on ladder tipping risk. For this experimental setup, regression estimates indicate reaching and lean distance of 113 cm and 29 cm from the ladder midline, respectively, would lead to ladder tipping on average. These findings assist with developing thresholds of unsafe reaching and leaning on a ladder, which can aid in reducing ladder falls.