The Musculo-Skeletal Systems
The Musculo-Skeletal systems include specific systems such as the skeletal system and the muscular system. These two systems combine to produce movement. To understand how these two systems combine, we need to also understand: - types of muscular contractions - how muscles work in pairs (agonist and antagonist) - the different types of joints - and the types of movements produced (anatomical movements). The Skeletal System The skeletal system consists of over 200 bones, joint, cartilage and ligaments. It is our main support structure in all physical activities and is responsible for; - Providing stability during movement - Providing the internal frame for our muscles and joints to work together to perform voluntary movement - Enabling our bodies to move efficiently, by providing support and leverage so that well-balanced movement can occur Muscular System The muscular system consists of over 650 muscles and it’s role is to allow the body to move in order to participate in day-to-day activities and to perform sports and physical activity. Muscles provide support to enable good posture, initiate movement and maintain essential bodily functions. Skeletal muscle is a voluntary muscle – this means that you have control over its movement and function. Muscular Contraction: There are different types of muscular contractions. Following are the most common types of muscular contraction in physical activity/sport. Isotonic concentric: all lifting exercises will require isotonic contractions. The muscle shortens as it contracts. For example – flexing your bicep when performing a bicep curl. Isotonic eccentric: instead of the muscle shortening as it contracts, it lengthens. For example if you lower yourself down a climbing rope, your bicep will lengthen. Isometric: you are creating tension in this muscle without it changing shape. For example the tension required to grip a tennis racquet or hold a cricket bat. Agonist/Antagonist: muscles work in pairs when contracting. One muscle in the pair contracts (agonist), the opposite muscle relaxes (antagonist). For example: your biceps are the (agonist) during a bicep curl and your triceps are the (antagonist). Types of Synovial Joints Joints – When two bones join they form what is called a joint. There are different types of joints in the body and they are characterised by the type and amount of movement they allow. In physical activity, the most common type of joint is a synovial joint which allows that joint to move freely in at least one direction. There are several types of synovial joints. Following is four classifications of synovial joints and examples of these in the body. Hinge: acts like a door hinge, only allowing flexion and extension in one direction. Eg: elbow, knee Ball and socket: allows for a wide range of movement, for example the shoulder and hip Saddle: provide stability to the bones while providing more flexibility than a hinge or gliding joint. Eg: thumb Pivot: is where one bone rotates around another, for example the first two cervical vertebrae (the atlas and the axis) Anatomical Movements Muscles act across joints to produce different movements. These movements are called 'anatomical movements'. The basic anatomical movements include those shown below: |
|