"Why Does My Body Have Particularly Soft Flesh?"

Our bones are covered with a significant amount of muscle and vascular tissue, accompanied by some fat. Numerous individuals observe that their flesh feels particularly soft, primarily attributed to a lack of muscle exercise. Moreover, a high body fat percentage further contributes to this softness. To address this, engaging in regular exercise can effectively enhance muscle training.

Muscle Movement

Muscle movement entails the contraction of muscles or specific positional changes derived from it. Nearly all metazoan movements can be classified under muscle movements, encompassing three primary forms:

1. Tissue Movement of Muscular Entities

This includes the bodies of flatworms, mollusk feet, and mammalian tongues, which consist of intricate muscle fiber networks. Movements initiated by muscular entities enable the free alteration of body shapes through flexion, extension, flattening, and other mechanisms.

2. Tubular Muscle Movement

It refers to the actions performed by hollowly arranged tubular muscles. Examples include the pumping action of the heart and the swimming movements of jellyfish and octopuses, resulting from rapid contraction and relaxation. The podial movement exhibited by echinoderms also falls into this category.

3. Skeletal Muscle Movement

This occurs within the exoskeleton or on the exterior of the endoskeleton, facilitated by muscles spanning movable joints. It encompasses diverse local and mobile movements leveraging the trunk and appendages.

Muscle Function

Muscle contraction pulls on bones, generating joint movements akin to a lever with three fundamental forms:

1. Balanced Lever Movement

The fulcrum lies between the effort and force points, exemplified by the atlanto-occipital joint's仰头 and 低头 movements.

2. Force-Saving Lever Movement

The effort point is positioned between the fulcrum and force point, as seen in ankle joint movements when lifting the heel during walking.

3. Speed Lever Movement

The force point is situated between the effort point and fulcrum, such as elbow joint movements when lifting heavy objects.

Muscles assist us in combating gravity. Muscle fibers regulate every movement, from gentle blinking to smiling. Thousands of minute fibers coalesce into muscle bundles, collectively forming a comprehensive muscular system. For instance, rock climbers rely on the relaxation and contraction of muscles for every upward step. Muscles primarily pull rather than push, with most belonging to skeletal muscles. They attach to bones via tendons, and these tightly bound tendon fibers function similarly to rubber bands.