Related Experiment Video
Updated: May 16, 2026
08:31
Versatility of Protocols for Resistance Training and Assessment Using Static and Dynamic Ladders in Animal Models
Published on: December 17, 2021
Research to improve extension ladder angular positioning
P Simeonov1, H Hsiao, J Powers
1Division of Safety Research, National Institute for Occupational Safety and Health, 1095 Willowdale Rd., Morgantown, WV 26505, USA. psimeonov@cdc.gov
Applied Ergonomics
|November 27, 2012
Summary
A new multimodal angle indicator significantly improves extension ladder positioning accuracy and speed compared to standard methods. This tool offers direct feedback, reducing fall risks and aiding user training for safer ladder use.
Area of Science:
- Occupational Safety and Ergonomics
- Engineering and Technology
Background:
- Suboptimal ladder inclination is a primary cause of extension ladder fall incidents.
- Improved ladder positioning methods are crucial for reducing fall risks and injuries.
Purpose of the Study:
- To comparatively evaluate a multimodal angle indicator against existing methods for extension ladder positioning.
- To assess the effectiveness of different ladder positioning techniques on angle accuracy and time efficiency.
Main Methods:
- Four positioning methods were tested: no-instruction, anthropometric, bubble level indicator, and multimodal indicator.
- Study involved 40 participants (20 experienced, 20 inexperienced) using 4.88m and 7.32m extension ladders.
- Performance metrics included final ladder angle and time taken for positioning.
Main Results:
- The multimodal indicator significantly improved ladder angle settings and required the least positioning time.
- The anthropometric method improved angle but had high variability and took longer.
- The bubble level indicator was accurate but significantly increased positioning time.
Conclusions:
- A multimodal indicator with direct, continuous feedback offers a viable approach for quick and accurate ladder positioning.
- This technology can enhance safety by reducing ladder instability and serve as a training tool for standard methods.
- The multimodal indicator concept has been developed into a smartphone application.
Related Concept Videos
01:12Adjusting a Traverse
In the site survey of a four-sided traverse, internal angles are essential to ensure geometric accuracy. The survey revealed that the sum of the measured internal angles was 359 degrees and 48 minutes, which is 12 minutes less than the expected 360 degrees. This discrepancy signals an error likely arising from measurement inaccuracies during the fieldwork.To rectify this error, the adjustment process involved distributing the 12-minute shortfall equally across the four internal angles. By...
01:29Relative Motion Analysis using Rotating Axes-Problem Solving
Consider a crane whose telescopic boom rotates with an angular velocity of 0.04 rad/s and angular acceleration of 0.02 rad/s2. Along with the rotation, the boom also extends linearly with a uniform speed of 5 m/s. The extension of the boom is measured at point D, which is measured with respect to the fixed point C on the other end of the boom. For the given instant, the distance between points C and D is 60 meters.
Here, in order to determine the magnitude of velocity and acceleration for point...
Here, in order to determine the magnitude of velocity and acceleration for point...
01:25Design Example: Traverse Angle Computations
Traverse angle computations are a critical component of surveying, used to compute the internal angles within a closed traverse. A traverse consists of a series of connected lines forming a closed loop, often used for land boundary delineation or mapping. Calculating the internal angles ensures accuracy in the traverse geometry and is essential for checking survey data integrity.The process begins with known azimuths and bearings of the traverse sides. Internal angles at each vertex are...
01:17Beams with Unsymmetric Loadings
Analyzing a supported beam under unsymmetrical loadings is essential in structural engineering to understand how beams respond to varied force distributions. This analysis involves calculating the deflection and identifying points where the slope of the beam is zero, which are crucial for ensuring structural stability and functionality.
The first moment-area theorem determines the slope at any point on the beam. This theorem indicates that the change in slope between two points on a beam...
The first moment-area theorem determines the slope at any point on the beam. This theorem indicates that the change in slope between two points on a beam...
01:30Machines: Problem Solving II
Machines are complex structures consisting of movable, pin-connected multi-force members that work together to transmit forces. Consider a lifting tong carrying a 100 kg load. It comprises movable sections DAF and CBG linked together with member AB.
01:29Trigonometry of Right Triangles
In a right triangle, trigonometric functions establish specific ratios that describe the relationship between the lengths of the triangle's sides and its acute angles. These relationships are foundational in understanding the structure of right-angled geometry. The sine function quantifies the proportion of the side opposite a given angle compared to the triangle's hypotenuse. In contrast, the cosine function expresses how the side adjacent to the angle relates to the hypotenuse in terms of...