[trustist-reviewer widget=”TR”]

Muscles have 5 main functions:

• Motion
• Movement of substances in the body
• Posture
• Heat production
• Organ volume regulation

Tendons connect muscles to bones; ligaments connect
bones to bones.

Like adults babies have 3 kinds of muscles:

1. Striated muscles: the voluntary muscles that operate the movements of the limbs, neck and face. They are all attached to the skeleton and are sometimes referred to as ‘skeletal muscles’. As babies grow, they develop more and more precise control over the actions of these muscles.
2. Smooth muscles: these are involuntary muscles as there is no voluntary control over them and their activities go unnoticed until something is wrong. Smooth muscles control  the movement of digested food through the intestines, the circular ones squeezing the gut and the longitudinal ones widening it.
3. Cardiac muscles: Cardiac muscles are striped muscles but they are also involuntary. A baby’s cardiac (heart) and respiratory muscles are well developed from birth as they are essential for breathing. Cardiac muscles respond to stimuli that cause babies to respond emotionally, modifying their heartbeat up or down. All 3 types of muscles can contract actively but can only expand passively. They work in muscle pairs with one muscle forcibly contracting while the other relaxes and allows itself to be stretched. (e.g. if biceps muscles in the arm contact, the arm bends but if triceps contract, the arm straightens itself again: the arm moves through these opposing contractions).Contraction occurs by a sliding filament mechanism.

A baby can move quite vigorously at birth and in utero. Although the muscle fibres are almost all present at birth, they are not yet fully developed; the fibres are small and watery and will only develop as the baby grows. The growth is rapid up to eighteen months but the fibres do not increase in number only but also in length and thickness, developing from the head down as with the
skeleton. They also increase in size from the inside out. Good muscle development requires physical activity, diet and hormonal balance within the body. As a baby become more active, the muscle development increases, but initially muscle power is essential for breathing, making the respiratory muscles larger than others muscles in the body.

Development of muscle control:

• Begins with the neck enabling a baby to lift its head.
•  By three months they are able to raise the chest and head.
•  By six to eight months the baby is usually capable of sitting unsupported for a limited time.
• Development of the legs muscles enables walking and standing.

How this relates to us…

Physical activity helps to develop muscle strength and co-ordination, which in turn enables motor development. Working to babies’ resistance is important to avoid over working the still forming muscles.