OBJECTIVES: The objectives of this pilot study were to analyze the electromyography (EMG) activity of masseter and anterior temporalis muscles during chewing in 2 different posture conditions: natural head posture (NHP) and maximum yet comfortable forward head posture (FHP) in healthy individuals; and to compare EMG activity between subjects based on their NHP during chewing. METHODS: Fifteen subjects participated. Sagittal head posture in sitting position was clinically assessed using a plumb line. Participants were classified as having FHP or upright head posture (UP). Surface EMG was used to evaluate superficial masseter and anterior temporalis bilaterally during chewing in NHP and FHP. Three trials with five chewing cycles were recorded. EMG data were normalized using a maximum voluntary contraction. An independent t-test was used to calculate differences between sides. If no differences were found, both sides were analyzed together. To analyze differences between the 2 conditions, a paired t-test was used. Independent t-test was used to calculate difference between subjects with UP and FHP. RESULTS: A significant increase in muscle activity was found for masseter muscle in the FHP condition. No differences were found in muscle activity in natural head position by posture classification. A trend of increased activity was observed for masseter and temporalis muscles during chewing in FHP. CONCLUSION: Head and neck posture was found to influence masticatory muscle activity during the function of chewing. The results of this study may help clinicians to better understand the association between head and neck posture alterations with masticatory muscles related disorders.
OBJECTIVES: The objectives of this pilot study were to analyze the electromyography (EMG) activity of masseter and anterior temporalis muscles during chewing in 2 different posture conditions: natural head posture (NHP) and maximum yet comfortable forward head posture (FHP) in healthy individuals; and to compare EMG activity between subjects based on their NHP during chewing. METHODS: Fifteen subjects participated. Sagittal head posture in sitting position was clinically assessed using a plumb line. Participants were classified as having FHP or upright head posture (UP). Surface EMG was used to evaluate superficial masseter and anterior temporalis bilaterally during chewing in NHP and FHP. Three trials with five chewing cycles were recorded. EMG data were normalized using a maximum voluntary contraction. An independent t-test was used to calculate differences between sides. If no differences were found, both sides were analyzed together. To analyze differences between the 2 conditions, a paired t-test was used. Independent t-test was used to calculate difference between subjects with UP and FHP. RESULTS: A significant increase in muscle activity was found for masseter muscle in the FHP condition. No differences were found in muscle activity in natural head position by posture classification. A trend of increased activity was observed for masseter and temporalis muscles during chewing in FHP. CONCLUSION: Head and neck posture was found to influence masticatory muscle activity during the function of chewing. The results of this study may help clinicians to better understand the association between head and neck posture alterations with masticatory muscles related disorders.
Authors: D Ap Biasotto-Gonzalez; F Berzin; Joelma Magalhães da Costa; Tabajava Oliveira de Gonzalez Journal: Electromyogr Clin Neurophysiol Date: 2010-03
Authors: Yasmin El Hage; Fabiano Politti; Dowglas F Magalhães de Sousa; Carolina Marciela Herpich; Igor Phillip dos Santos Gloria; Cid André Fidelis de Paula Gomes; Ana Paula Amaral; Nívea Cristina de Melo; Thais Correa da Silva; Eric Edmur Camargo Arruda; Cesar Ferreira Amorim; Inaê Caroline Gadotti; Tabajara Oliveira Gonzalez; Fausto Berzin; Sandra Kalil Bussadori; Marília Barbosa Santos Garcia; Bruno Roberto Borges Barbosa; Daniela Aparecida Biasotto-Gonzalez Journal: Trials Date: 2013-10-01 Impact factor: 2.279