(こっかくきん)

こっかくきん
noun
skeletal muscle
1. skeletal muscle
One of the three main types of muscle tissue in the body. Skeletal muscles are attached to bones by tendons and, unlike smooth or cardiac muscle, are under voluntary control — they contract when we choose to move. They make up roughly 40% of body weight in healthy adults.
骨格筋(こっかくきん)(きた)える。
To train the skeletal muscles.
運動(うんどう)不足(ぶそく)骨格筋(こっかくきん)(おとろ)えた。
Due to lack of exercise, my skeletal muscles have weakened.
骨格筋(こっかくきん)自分(じぶん)意思(いし)(うご)かすことができる。
Skeletal muscles can be moved by one's own will.
加齢(かれい)とともに骨格筋(こっかくきん)(りょう)()ると、転倒(てんとう)()たきりのリスクが(たか)まる。
When skeletal muscle mass decreases with age, the risks of falling and becoming bedridden rise.

Composed of 骨格(こっかく) (skeleton; body frame) and (きん) (muscle). A formal, medical-sounding term used in anatomy, sports science, health writing, and nutrition articles. Emphasizes the muscles that move the skeleton, in contrast with the involuntary muscles of the internal organs and the heart.

USAGE:
Very common in fitness, rehabilitation, and aging-related health contexts, especially around topics such as sarcopenia (サルコペニア}) and strength training for older adults. Body composition scales and medical reports often display {骨格筋(こっかくきん)(りょう) (skeletal muscle mass) as a separate figure from total muscle mass and body-fat percentage.

COMMON COLLOCATIONS:

  • 骨格筋(こっかくきん)(きた)える: to train the skeletal muscles
  • 骨格筋(こっかくきん)(りょう): skeletal muscle mass
  • 骨格筋(こっかくきん)(おとろ)え: deterioration of skeletal muscles
  • 骨格筋(こっかくきん)収縮(しゅうしゅく): contraction of skeletal muscle
  • 骨格筋(こっかくきん)(りつ): skeletal muscle percentage (of body weight)

SIMILAR WORDS:

  • 心筋(しんきん): cardiac muscle — the muscle tissue of the heart, involuntary
  • 平滑筋(へいかつきん): smooth muscle — the involuntary muscle of internal organs and blood vessels
  • 筋肉(きんにく): muscle — the everyday word for muscle in general
  • (すじ): sinew; muscle fiber — a more informal and less technical term
  • 骨格(こっかく): skeleton; (body) frame — the bony framework of the body