Skeletal System

3 functions of the skeleton

 

•Movement – joints

•Shape/Support – keep us upright

•Protection e.g. the skull and other organs.

JointsThe Hinge Joint This includes the Elbow and the Knee Joint.

It is Capable of Bending (Flexion) and Straightening (Extension) E.g.

•the elbow flexes on a bicep curl, and extends to straighten the arm.

•The knee joint, flexes when a footballer prepares to kick the ball and then extends to strike the ball.

The joint is connected by 2 smooth shallow surfaces and held in place by strong Ligaments

Joints

The Ball and Socket Joint This includes the Hip Joint and the Shoulder Joint.

It is capable of flexion, extension, adduction, abduction and rotation.  •It is called a ball and socket joint as one bone such as the Humerous (arm) is a long bone with a ball like end and the other is a cub shaped socket (shoulder) in which the femur fits in to. These are covered in cartilage and held in place by ligaments.

Examples include•Bowling in cricket (forward rotation), swimming back crawl (backward rotation) •Abduction occurs as the arm is brought behind the body in preparation to throw a ball or javelin.

Movements

Your Turn:

• Name the type of joint labelled A-D

• Which joints can only cause flexion and extension.

• What ranges of movement are joints A-D in

• What ranges of movement are B-C in.

Skeletal System

Learning Objectives: by the end of the lesson you will have the• knowledge of the different sports injuries that can happen to the skeletal system

•Knowledge of exercise and the effects it has on the skeletal system

•Knowledge of diet and the effects it has on the skeletal system

Nasty Sporting injuries

Types of fractures • Compound: Broken bone that comes through

the skin

• Greenstick: Break only part way across the bone

• Simple: Fracture in one line, no displacement

• Stress: Overuse injuries usually in weight bearing areas such as lower leg (shin splints)

A Fracture is a break or crack in the bone. Fractures occur due to direct or indirect force and this mostly happens in contact sports.

Direct Force = Being Kicked

Indirect Force = Falling awkwardly from taking a header.

Symptoms: Difficulty moving the limb, Localised pain, Distortion of shape, Swelling, Bruising.

Guess the Fracture

Types of Joint injuriesDISLOCATION Tennis elbow Golfer’s elbow Cartilage Tear

Where the bone is moved out of normal position.Located at joints particularly shoulder, thumb and fingerSymptoms: pain and distortion of natural shape.

Wear and tear of the muscle and tendons in the forearm caused by poor technique or the wrong size grip.Symptoms: Pain on the outside of the arm and elbow. Stiffness at the elbow joint.

This affects the muscles and tendons responsible for flexing the wrist and is caused through overuse.Symptoms: Pain around the elbow joint, normally on the inside of the joint.

Cartilage at the end of bones can be damaged or can deteriorate with age. A torn piece of cartilage can wedge itself between the bones. Symptoms: Pain around the joint, swollen Knee and difficulty moving

The effects of regular exercise on the skeletal system

• The long-term effects of exercise and physical activity on the skeletal system are increased bone density and strengthening of ligaments and tendons thus making the joints stronger and supple.

• Only weight-bearing exercise performed regularly over a prolonged period of time such as weight lifting, walking, running, tennis and aerobics are very important as they prevent osteoporosis in later life (the weakening of the bones). This is a disease which is associated with the elderly whereby bones fracture much easier

Test your knowledge• What type of injury is a dislocation? (1)

• What is the cause of tennis elbow? (1)

• Which physical activity would you choose if you wanted to improve your bone strength(1) cycling

swimming

running

• Explain why you chose the activity. (3)

Diet and the Skeletal system

Explain in your own words how the items on the previous slide help the skeletal system

Diet (effect of calcium and vitamin D on bones)

• Calcium is a mineral that is found in dairy products. Calcium helps to build strong bones, increases bone density and stop the onset of osteoporosis. Vitamin D helps to maintain healthy bones by helping the body to absorb the calcium. Calcium is found in milk, cheese and yoghurt. Vitamin D is made by the body when the skin is exposed to sunlight