Muscles-action and location

We will now examine the major muscles in the body. As a fitness leader you will be expected to know these names of these muscles, their location and their action as they move different joints in the body. You will need this knowledge to explain exercises to clients. You will also need to know the names of muscles as you communicate with other health professionals.

1. Major muscles of the anterior chest Pectoralis Major Pectoralis minor Serratus anterior

Where are these muscles?

Summary of actions and location MuscleActionLocation Pectoralis majorFlexes adducts and medially rotates the arm Anterior chest wall Pectoralis MinorAdducts and medially rotates the arm Anterior chest deep to pectoralis major Serratus anteriorHolds scapula against ribs rotates scapula upwards an laterally Lies beneath and inferior to pectoralis major and has a serrated appearance.

Summary of muscles and joints MuscleJoints which move Pectoralis majorThe shoulder joint Pectoralis MinorThe shoulder joint Serratus anteriorThe scapulo-thoracic region ( no specific joint)

Learning Tools Find the muscles you have just learnt on a fellow student or friend. As you identify them review the names, actions of these muscles and joints which move as these muscles contract. List the actions of these muscles What exercises can you think of that would strengthen these muscles?

2. Major Muscles of the posterior trunk and back Latissimus dorsi Trapezius (lower fibres) Rhomboid major and minor Quadratus lumborum Erector spinae

Where are these muscles?

Summary of actions and location MuscleActionLocation Latissimus DorsiExtends, adducts and medial rotates the arm Lower trunk extending up to the arm Trapezius (lower fibres) Retracts and depresses the scapula The posterior trunk from the tip of the shoulder down to the lumbar spine RhomboidsRetracts the scapula Medial border of the scapula to the spine

Summary of actions and location cont… MuscleActionLocation Quadratus Lumborum Side bending of the trunk Hitching of the pelvis Between the lowest rib and iliac crest Erector Spinae- (made up of three muscles) Iliocostalis, Longissimus, Spinales, Trunk extension and some trunk side flexion On either side of the spine, with some extensions out onto the ribs

Summary of muscles and joints MusclesJoint action Latissimus DorsiThe shoulder joint Trapezius (lower fibres) The scapulo-thoracic region ( no specific joint) Quadratus Lumborum The lumbar spine intervertebral/facet joints and the sacro-liac joint Erector SpinaeSpine intervertebral/facet joints RhomboidsThe scapulo-thoracic region ( no specific joint)

Learning Tools Find the muscles you have just learnt on a fellow student or friend. As you identify them review the names, actions of these muscles and joints which move as these muscles contract. List the actions of these muscles. How would you strengthen these muscles?

3. Major muscles of the neck Sternocleidomastoid Trapezius

Where are these muscles?

Summary of actions and location MuscleActionLocation Sternocleido- mastoid Head flexion, rotation and lateral flexion Front of neck TrapeziusHead and neck side flexion Hitching scapula and shoulder Side of neck down to the tip of the shoulder

Muscles and Joint Action MuscleJoint Action Sternocleido -mastoid Cervical intervertebral/ facets joints TrapeziusCervical intervertebral/ facets joints

Learning Tools Find the muscles you have just learnt on a fellow student or friend. As you identify them review the names, actions of these muscles and joints which move as these muscles contract. List the actions of these muscles How would you strengthen these muscles?

4. Major muscles of the upper limb Deltoid Biceps brachii Triceps brachii Forearm flexors Forearm extensors

Where are these muscles?

Summary of actions and location MuscleActionLocation DeltoidAbduction of the arm Tip of the shoulder Biceps brachiiFlexion of the elbow and shoulder Front of the arm between shoulder and elbow Triceps brachiiExtension of the elbow and shoulder Back of the arm between the shoulder and elbow

Summary of actions and location MuscleActionLocation Forearm flexors ( The major ones are - Flexor carpi radialis, flexor carpi ulnaris, flexor digitorum, palmaris longus) Flexing the wrist and fingers From the medial epicondyle down the anterior or palmar side of the forearm Forearm extensors (The major ones are- Extensor carpi radialis longus &brevis, extensor carpi ulnaris, extensor digitorum) Extending the wrist and fingers From the lateral epicondyle down the posterior or dorsal side of the forearm.

Muscles and joint action MusclesJoint Action DeltoidThe shoulder joint Biceps brachii The elbow and shoulder joint Triceps brachii The elbow and the shoulder joint Forearm flexors The wrist joint and some move the finder joints Forearm extensors The wrist joints and some move the finder joint

Learning Tools Find the muscles you have just learnt on a fellow student or friend. As you identify them review the names, actions of these muscles and joints which move as these muscles contract. List the actions of these muscles

5. Major muscles of the abdominal region Rectus abdominis External and Internal oblique Transverse abdominis

Where are these muscles?

Summary of actions and location MuscleActionLocation Rectus abdominis (The six pack) Trunk flexionStraight up and down from the ribs to the pelvis External and Internal oblique Trunk flexion, rotation and side flexion Diagonal muscles on the side of the trunk Transverse abdominis Trunk and lumbar spine core stability Circular muscle deep to other abdominal muscles.

Muscles and Joint Action MuscleJoint Action Rectus abdominis Thoracic and lumbar spine intervertebral / facets joints Sacro-iliac joint External and Internal oblique Thoracic and lumbar spine intervertebral / facets joints Transverse abdominis Lumbar spine intervertebral / facets joints

Learning Tools Find the muscles you have just learnt on a fellow student or friend. As you identify them review the names, actions of these muscles and joints which move as these muscles contract. List the actions of these muscles. How would you strengthen these muscles?

6. Major muscles of the lower limb Gluteals- maximus, medius and minimus Quadriceps- vastus medialis, lateralis, intermedialis rectus femoris Hamstrings- biceps femoris, semitendinosus, semimembranosus Calf- Gastrocnemius, soleus Tibialis anterior

Where are these muscles?

Summary of actions and location MuscleActionLocation Gluteus maximusHip extensionMajor muscle base of trunk covering the pelvis Gluteus mediusHip abduction medial rotation and stabilisation of the hip Lateral posterior pelvis, slightly lateral to the glut.max. Gluteus minimusHip abduction medial rotation and stabilisation of the hip Sits deep to the glut max.

Muscles and joint action MuscleJoint Action Gluteus maximus Hip joint Gluteus medius Hip joint Gluteus minimus Hip joint

Learning Tools Find the muscles you have just learnt on a fellow student or friend. As you identify them review the names, actions of these muscles and joints which move as these muscles contract. List the actions of these muscles What exercises can you think of that would strengthen these muscles?

Where are these muscles?

Summary of actions and location MuscleActionLocation Biceps femorisExtends the hip and flexes the knee The back of the thigh, the lateral side SemitendinosusExtends the hip and flexes the knee The back of the thigh, the medial side SemimembranosusExtends the hip and flexes the knee The back of the thigh, the medial side

Muscles and joint action Muscle Joint Action Biceps femoris Hip joint and knee joint Semitendinosus Hip joint and knee joint Semimembranosus Hip and knee joint

Learning Tools Find the muscles you have just learnt on a fellow student or friend. As you identify them review the names, actions of these muscles and joints which move as these muscles contract. List the actions of these muscles What exercises can you think of that would strengthen these muscles?

Where are these muscles?

Summary of actions and location MuscleActionLocation Rectus femorisFlexes the hip and extends the knee Main muscle in the front of the thigh Vasti lateralisExtends the kneeMajor muscle sitting slightly lateral to rectus femoris Vasti medialisExtends the kneeMajor muscle sitting slightly medial to rectus femoris Vasti intermedialisExtends the kneeSits under the rectus femoris

Muscles and joint action MuscleJoint Action Rectus femoris Hip and knee joint Vasti lateralis Knee joint Vasti medialis Knee joint Vasti intermedialis Knee joint

Learning Tools Find the muscles you have just learnt on a fellow student or friend. As you identify them review the names, actions of these muscles and joints which move as these muscles contract. List the actions of these muscles What exercises can you think of that would strengthen these muscles?

Where are these muscles?

Summary of actions and location MuscleActionLocation GastrocnemiusFlexes the knee and plantaflexes (extends) the ankle The major muscle in the calf SoleusPlantaflexes the ankle Sits deep to gastrconemius

Muscles and Joint Action MuscleJoint Action GastrocnemiusKnee joint and ankle joint SoleusAnkle joint

Learning Tools Find the muscles you have just learnt on a fellow student or friend. As you identify them review the names, actions of these muscles and joints which move as these muscles contract. List the actions of these muscles What exercises can you think of that would strengthen these muscles?

Where are these muscles?

Summary of actions and location MuscleActionLocation Tibialis AnteriorAnkle dorsiflexion Below the knee, the just lateral to the shin.

Muscle and Joint Action MuscleJoint Action Tibialis AnteriorAnkle joint

Learning Tools Find the muscles you have just learnt on a fellow student or friend. As you identify them review the names, actions of these muscles and joints which move as these muscles contract. List the actions of these muscles What exercises can you think of that would strengthen these muscles?