The skeletal system forms the structural framework of the human body. Composed of 206 bones in adulthood, it plays a central role in enabling movement, supporting soft tissues, protecting internal organs, producing blood cells, and storing essential minerals such as calcium and phosphorus. The bones of the skeleton are classified by shape—long, short, flat, irregular, and sesamoid—each adapted to specific structural and functional roles within the body.

Bones do not function in isolation. They are joined by joints and moved by muscles, making the skeletal system essential for biomechanical performance. Bones act as levers, and joints act as pivot points, allowing for complex, coordinated movement. The type of joint—fibrous, cartilaginous, or synovial—determines the degree of mobility. Synovial joints, in particular, are central to most sporting and functional movements due to their high range of motion. These joints are characterised by features such as articular cartilage, a joint capsule, synovial membrane, and synovial fluid, all of which reduce friction and support efficient movement.

The axial skeleton includes the skull, vertebral column, ribs, and sternum. It provides protection for the brain, spinal cord, and vital thoracic organs, and it supports the upright posture of the human body. The vertebral column is divided into five regions—cervical, thoracic, lumbar, sacral, and coccygeal—each with specific roles in flexibility, protection, and load-bearing.

The appendicular skeleton consists of the shoulder girdle, pelvic girdle, and the upper and lower limbs. It facilitates locomotion and manipulation of the environment, making it crucial in both daily function and athletic performance. The shoulder and pelvic girdles act as anchors for limb movement while enabling a broad range of motion.

Bone tissue is dynamic. It continually remodels in response to mechanical stress and physiological demands, a process influenced by hormones, physical activity, and nutrition. The outer layer of bone, known as compact bone, provides strength and rigidity, while the inner spongy bone contains red marrow responsible for haematopoiesis—the production of blood cells.

In movement and exercise, the skeletal system interacts closely with the muscular and nervous systems. It provides the sites for muscle attachment and acts as a system of levers which, when acted upon by muscle force, produce coordinated movement. Strong, healthy bones are critical for absorbing impact, maintaining posture, and transmitting forces efficiently through the body.

Understanding the skeletal system is essential for appreciating how the body moves, adapts, and performs under different physical demands. It is a foundation for further exploration into biomechanics, exercise physiology, and injury prevention, and it provides the structural basis for all human performance.

Overview