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Muscle recruitment patterns during pushing and pulling tasks (1996-1998)
Wattana Jalayondeja, PhD (PhD Research)
The specific aim of this study is to investigate the recruitment orders of the lower extremity,
the trunk, and the upper extremity muscles during isometric voluntary pushing and pulling
exertions. This study will provide two benefits: a better comprehension of mechanisms of injury
caused by pushing and pulling tasks, and a development of a work hardening program in pushing
and pulling exertions for post-traumatic patients.
The hypotheses to be tested in this study are:
- The muscle recruitment patterns of postural synergy muscles during pushing and pulling tasks are
in a caudal-to-cranial order.
- The anterior postural synergy muscles are mainly recruited at a low pushing task.
- The posterior postural synergy muscles are mainly recruited at a low pulling task.
- Patterns of the muscle recruitment are dependent upon the magnitude of forces generated during
pushing or pulling tasks.
The optimum postures for pushing and pulling used in industries are assigned. Twenty-five,
50, 75, and 100% of maximum pushing and pulling forces will be tested. Surface electromyography
(EMG) of the trunk, lower extremity and upper extremity muscles, pushing and pulling forces
against a force transducer, and reaction forces on a force plate will be measured simultaneously.
The onsets of EMG activity of the muscles during pushing and pulling exertions will be determined
along with the muscle recruitment patterns. In addition, co-contraction of muscles will be
investigated.
This is a Ph.D. thesis project. The project is in the study design stage. The project has been
supported by a scholarship by the Government of Thailand and received one of six John J. O'Toole
Safety Memorial Scholarship Awards given in 1996 by New York University. |
