Related Experiment Video
Updated: Aug 4, 2026

Using a Split-belt Treadmill to Evaluate Generalization of Human Locomotor Adaptation
Published on: August 23, 2017
Laboratory evaluation of belt usage with apple buckets
Giulia Earle-Richardson1, Paul L Jenkins, Andris Freivalds
1Northeast Center for Agricultural and Occupational Health, Cooperstown, New York, NY 13326, USA. gearlerichardson@nycamh.com
Background:
Migrant and seasonal orchard harvest workers experience musculoskeletal strain caused by carrying heavy loads and holding awkward postures. An ergonomic hip belt designed to redistribute weight from the upper back, neck, and shoulders to the hips was evaluated.
Methods:
A comparison of muscle exertion (using electromyography [EMG]) of four key back and shoulder muscles and shoulder surface pressure (using a surface pressure sensor [PS]) was made among 10 laboratory volunteers under intervention and control conditions, in two postures (standing erect [0 degrees ]) and flexed [45 degrees ]).
Results:
All but one measure showed a significant reduction in the flexed posture with the intervention. Two of eight measures showed a significant reduction in the erect posture. Correlations with shoulder discomfort were found for deep shoulder EMG (r=0.71, P=0.021) and shoulder surface pressure (r=0.58, P=0.082).
Conclusions:
The hip belt intervention produces significant reductions in muscle activity while in a posture commonly assumed during orchard work.
Related Concept Videos
Frictional Forces on Flat Belts
Flat Belts: Problem Solving
Vebe Test
To conduct the test, concrete is placed into the slump cone. The concrete is filled in layers and...
Design Example: Aggregate Gradation
The grading, or particle-size distribution, of sand is determined using sieve analysis, with standard sizes ranging from 150 μm to 10 mm (ASTM No. 100 sieve to 3⁄8 in. sieve). Sand is sampled...

