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Measuring fatigue related to facial muscle function
1Department of Physical Therapy, School of Health and Rehabilitation Sciences, University of Pittsburgh Medical Center, PA, USA.
Archives of Physical Medicine and Rehabilitation
|October 1, 1995
Summary
Facial muscles significantly fatigue with sustained maximal voluntary contractions for brow raise, smile, and pucker expressions. However, these muscles show more resistance to fatigue during repeated, brief contractions, offering insights for rehabilitation.
Area of Science:
- Neurology
- Biomechanics
- Physiology
Background:
- Facial muscle fatigue is a critical factor in neuromuscular function.
- Understanding fatigue patterns in healthy individuals is essential for diagnosing and treating facial neuromuscular disorders.
Purpose of the Study:
- To investigate the expression of facial muscle fatigue in individuals without any muscle impairments.
- To utilize surface electromyography (EMG) for quantifying facial muscle activity during fatigue tests.
Main Methods:
- A descriptive study involving 20 healthy volunteers (5 males, 15 females; ages 20-50).
- Two fatigue tests were administered: a 10-second sustained contraction and a series of 25 repeated 3-second contractions.
- Surface EMG recorded muscle activity during voluntary maximal contractions for brow raise, smile, and pucker expressions.
Main Results:
- Sustained contractions showed significant fatigue across all expressions: brow raise (34.51%), smile (22.96%), and pucker (29.05%).
- Repeated contractions revealed significant fatigue only in the smile expression (11.62%), with brow raise (7.27%) and pucker (4.22%) showing no significant fatigue.
Conclusions:
- Facial muscles significantly fatigue over time with sustained maximal voluntary contractions.
- Facial muscles demonstrate greater resistance to fatigue from repeated, brief contractions.
- Quantifying facial muscle fatigue in healthy individuals provides a baseline for rehabilitation outcome measures in patients with facial neuromuscular dysfunction.
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