The human skeleton consists of 206 bones, many of which move or hinge at joints and which, enable the body to achieve a variety of actions, such as running, throwing, striking, pulling and pushing. The human skeleton was created by evolution to perform six functions:
I. To provide a lever system against which muscles can pull
II. To provide a large surface area for the attachment of muscles
III. To protect delicate organs (i.e the cranium protects the brain)
IV. To give shape to the body
V. To give support to the body (i.e the firm construction of the thorax that permits breathing)
VI. To manufacture red blood cells and store fat, calcium and phosphate
The Muscular System
One of the important functions of the human body is to enable movement. Physical activity is achieved as a result of over 600 muscles that contract or shorten, thereby facilitating the movement of the skeleton across its joints. Muscles are the converters of energy.
3. Name the insertion, origin and state the functions of the following muscles.
Muscle
Function
Insertion
Origin
Pectoralis major
Flexes upper arm and adducts upper arm
Humerous
Sternum
Clavicle
Rib cage
Latissimus Dorsi
Extends upper arm
Adducts upper arm
Humerous
Vertebra (T6-L5)
Deltoid
Flexes upper arm
Adducts upper arm
Extends upper arm
Humerous
Clavicle
Scapula
Acromion
Biceps Brachi
Flexes lower arm
Radius
Scapula
Triceps
Extends lower arm
Oclearanon
Humerus
Scapula
Gluteus Maximus
Extension of the thigh
Femur
Illium
Sacrum
Coccyx
Gluteus Meduis & Mnimus
Abduction of the thigh
Femur
Illium
Hamstring Group
Flexes to lower your legs
Extension of the lower legs
Tibia, Fibula, Head of fibula and lateral of the Londyloid
Ischium
Long Head
Short Head
Quadricep Group
Flexes the thigh
Extends the lower leg
Tibia (VIA Patella tendon)
Illium
Femur
Satorius
Flexes the hip and the knee
Anterior superior
Illiac Spine
Tibia
4. Movement actions and their functions
Action
Joint Used
Movement Pattern
Agonist Muscle
Type of Muscular Contraction
Lever Class
Leg Action in sprinting
Hip
Flexion + Extension
Gluteus Maximus / Hamstrings
Concentric
3
Knee
Flexion + Extension
Quadriceps
Eccentric / Concentric
3
Ankle
Plantar Flexion
Gastrocenemius + Satorius
Eccentric / Concentric
2
Overarm Throw
Shoulder
Flexion
Deltoid / Pectorals
Concentric
3
Elbow
Extension + Adduction
Triceps
Concentric
1
Leg in Squat
Hip
Flexion + Extension
Gluteus Maximus
Eccentric / Concentric
3
Knee
Flexion + Extension
Quadriceps
Eccentric / Concentric
3
Anle
Dorsi Flexion + Plantar Flexion
Solius / Gastrocenemius
Eccentric / Concentric
2
Arm Action in Pushup
Shoulder
Extension + Flexion
Deltoids / Pectorals
Eccentric / Concentric
3
Elbow
Flexion + Extension
Triceps
Eccentric / Concentric
1
Leg action in Kick
Hip
Flexion
Quadriceps rectus, Abdominals
Concentric
3
Knee
Extension
Quadriceps
Concentric
3
Ankle
Plantar Flexion
Tibialis Anterior
Eccentric
3
5. Explaining joints their actions and their plane movements.
Joint
Action
Plane
Hip
Flexion
Median
Extension
Median
Abduction
Frontal
Adduction
Frontal
Lateral Rotation
Horizontal
Medial Rotation
Horizontal
Knee
Flexion
Median
Extension
Median
Medial Rotation (When Fixed)
Horizontal
Lateral Rotation (When Fixed)
Horizontal
Ankle
Dorsi Flexion
Median
Plantar Flexion
Median
Inversion
Frontal
Eversion
Frontal
Shoulder
Flexion
Median
Extension
Median
Adduction
Frontal
Abduction
Frontal
Horizontal Abduction
Horizontal
Medial Rotation
Horizontal
Lateral Rotation
Horizontal
Elbow
Flexion
Median
Extension
Median
Pronation
Horizontal
Supination
Horizontal
Wrist
Flexion
Median
Extension
Median
6. What lever system operates when we nod our head?
The First Class Lever system operates when we nod our head, in the First Class Lever system the Fulcrum lies between the effort and the resistive force.
7. What lever system is operating when we rise to out our toes prior to a dive?
The Second Class Lever system is operating when we raise our toes prior to a dive.
In the second-class lever system the resistance lies between the Fulcrum and the Effort.
8. What lever system is operating when we perform a bicep curl?
The Third Lever Class Lever System is operating when we perform a bicep curl.
In the Third Class Lever System the effort is between the Fulcrum and the Weight.
9. Write a paragraph explaining how levers can affect performance in sport.
The skeleton provides us with a lever system that allows us to move. A lever is a rigid structure (I. E Bone) that rotates around a fixed joint (Falcrum) and is used to apply a force (Effort) against a resistance. The levers provide a larger range of movement, like the extension of an arm in a tennis shot, which is provided by the movement of a lever. The lever decreases resistance and makes a strike in sport.