Connective Tissue & Muscles
Connective Tissue
To help us get a better understanding of joint movement, we can look at how they are connected, through three different types of connective tissue…
Ligaments
These connect the bones together. Their tightness can determine each individual’s range of movement.
Tendons
These connect muscles to bones and create movement by transferring forces created by muscle contractions to the bone that it is connected to. This, in turn, causes that bone to move using the nearest joints to that bone.
Cartilage
Essentially this is a cushion between the bones. This is often a cause of pain when it gets worn down through overuse or age.
Muscles
Muscles are bands of soft tissue fibres that contract or relax. They are attached to bones through tendons and are responsible for moving those bones through one’s joints.
Generally speaking, muscles make three different types of contractions, based on muscles working with and against one another as they contract or relax.
Concentric Muscle Contraction
This is where the muscle shortens when contracting. A snowboarding example of this is when pulling up the toes (dorsiflexion), moving through the ankle joint. Here we make a concentric muscle contraction in the tibialis anterior (the muscle beside the shin), reducing the length of it as it tenses.
Eccentric Muscle Contraction
This is where the muscle lengthens when contracting. For concentric contraction to work, the muscle must be paired with another muscle that works in the opposite way. In the example of dorsiflexion in the ankle, it is the gastrocnemius (the calf muscle) that works eccentrically, increasing in length as it stretches.
Isometric Muscle Contraction
This is where the muscle does not change in length when contracting. This happens when two opposing muscles contract at the same time. An example of this would be holding a static position where the body is tense but has limited movement, like a stance used in martial arts.
Another example is when tensing the abdominal muscles (stomach) before being punched in the belly. Isometric muscle contraction is used much more regularly in snowboarding than most other sports. Even the basic stance requires a degree of isometric muscle contraction.