Asset Details
Do you wish to reserve the book?
Rat superficial masseter operates at long lengths during biting
Hey, we have placed the reservation for you!
By the way, why not check out events that you can attend while you pick your title.
Oops! Something went wrong.
Looks like we were not able to place the reservation. Kindly try again later.
Are you sure you want to remove the book from the shelf?
Rat superficial masseter operates at long lengths during biting
Do you wish to request the book?
Rat superficial masseter operates at long lengths during biting
Please be aware that the book you have requested cannot be checked out. If you would like to checkout this book, you can reserve another copy
We have requested the book for you!
Your request is successful and it will be processed during the Library working hours. Please check the status of your request in My Requests.
Oops! Something went wrong.
Looks like we were not able to place your request. Kindly try again later.
Journal Article
Rat superficial masseter operates at long lengths during biting
2025
Overview
The operating length ranges of mammalian jaw muscles have been estimated using twitch contractions or force measurements at the bite point, prompting a consensus that jaw muscles operate at short lengths on their force-length (FL) curve. However, since activation intensity truncates muscle optimal length (
L
O
), we hypothesized that
L
O
of rat superficial masseter (SM) would decrease with activation intensity, with high-force biting involving muscle shortening from long lengths on the FL curve. We measured muscle activation, strain, and force
in vivo
during biting on food with varying hardness and mapped the
in vivo
data from each muscle (
N
= 6) onto its FL relationship, measured
in situ
. Submaximal
L
O
was approx. 12% shorter than twitch
L
O
, and SM bite forces averaged 4.1 ± 3.9 N/cm
2
(mean ± S.D.) and reached 10.6 N/cm
2
, corresponding to muscle activation and food hardness. Length operation ranged from 7% below
L
O
(ascending FL plateau), to 27% beyond (descending limb). The finding that jaw muscles operate at long, potentially unstable lengths, particularly during hard food biting significantly expands our understanding of skeletal muscle function, with broad implications for craniofacial evolution, muscle mechanics and control, and healthy as well as pathological function of the jaw musculoskeletal system.
Publisher
Nature Publishing Group UK,Nature Publishing Group,Nature Portfolio
Subject
/ 631/443
/ Animals
/ Biting
/ Food
/ Force
/ Hardness
/ Humanities and Social Sciences
/ Jaw
/ Male
/ Masseter Muscle - physiology
/ Muscle Contraction - physiology
/ Muscles
/ Rats
/ Science
