title: Evaluation of repetitive isometric contractions on the heads of triceps brachii muscle during grip force exercise.
abstract: OBJECTIVE
  Normally, surface electromyography electrodes are used to evaluate the activity of superficial muscles during various kinds of voluntary contractions of muscle fiber. The objective of the present study was to investigate the effect of repetitive isometric contractions on the three heads of the triceps brachii muscle during handgrip force exercise.
  
  
  METHODS
  Myoelectric signals were recorded from the lateral, long and medial heads of the triceps brachii muscle in 13 healthy males during maximal isometric contractions for 10 s of concurrent handgrip force and elbow extension. The subjects were asked to perform their contraction task five times with 3 minutes interval between two successive contractions.
  
  
  RESULTS
  Decreasing electromyographic activities were found for the lateral and long heads, and increasing for the medial head throughout the 5 different contractions. Electromyographic activities were found for the lateral head with mean=199.84, SD=7.65, CV=3.83%, the long head with mean=456.76, SD=18.10, CV=3.96%, and the medial head with mean=505.16, SD=8.47, CV=1.68%. Electromyographic activities among the three heads of triceps brachii were significantly different (F=3.82) at the alpha level of (p<0.05).
  
  
  CONCLUSIONS
  These findings support that repetitive isometric contractions decrease the contractile activity in the lateral and long heads, and increases in the medial head of the triceps brachii muscle during handgrip force exercise with full elbow extension, and the electromyographic activity changes are observed to be more significant at the long head as compared to the lateral and medial heads.
authors.affiliation: AI-Rehab Research Group, Universiti Malaysia Perlis, Kampus Pauh Putra, Perlis, Malaysia.
authors.forename: Md Asraf
authors.initials: MA
authors.lastname: Ali
authors.affiliation: AI-Rehab Research Group, Universiti Malaysia Perlis, Kampus Pauh Putra, Perlis, Malaysia.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Sundaraj
authors.affiliation: AI-Rehab Research Group, Universiti Malaysia Perlis, Kampus Pauh Putra, Perlis, Malaysia.
authors.forename: R Badlishah
authors.initials: RB
authors.lastname: Ahmad
authors.affiliation: AI-Rehab Research Group, Universiti Malaysia Perlis, Kampus Pauh Putra, Perlis, Malaysia.
authors.forename: Nizam Uddin
authors.initials: NU
authors.lastname: Ahamed
authors.affiliation: AI-Rehab Research Group, Universiti Malaysia Perlis, Kampus Pauh Putra, Perlis, Malaysia.
authors.forename: Md Anamul
authors.initials: MA
authors.lastname: Islam
authors.affiliation: Medical Officer, Malaysian Ministry of Health, Malaysia.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Sundaraj
mesh_terms: D000328:Adult; D004576:Electromyography / Q000379:methods*; D018737:Hand Strength / Q000502:physiology*; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D008297:Male; D009119:Muscle Contraction / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology; D055815:Young Adult
keywords: Surface electromyography; grip force; isometric contraction; triceps brachii muscle