1. More moveable part moves towards the less moveable part. 2. The distal bone/part moves towards the proximal bone/part
Origin: Proximal attachment. ( Where the muscle starts) Muscle contracts towards the origin Less movable OR stationary part Insertion: Distal attachment More movable part
1. What aspect/view am I looking at? 2. How many joints does it cross? 3. Where is the more movable or distal attachment going to move?
Using the skeletons….. 1. Put one end of rubber band on distal insertion ( green dot ). Hold on to rubber band. 2. Pull towards the proximal origin ( red dot ). Hold on to rubber band at the insertion. 3. Feel the body part spring into motion!
Triceps Brachii Location – Back of the arm Movement – Elbow Extension Extras Origin – LH: Infraglenoid tubercle of scapula LTH: Posterior shaft of humerus MH: Posterior humeral shaft distal to radial groove. Insertion – By common tendon into olecranon process of ulna.
Biceps Brachii Location- Anterior upper arm Movement – Elbow Flexion Forearm Supination Extra Has 2 origins (bi) Short head - coracoid process Long head – tubercle above glenoid cavity Insertion Radial Tuberosity
Rectus Femoris Location- Middle, Front Thigh Movement – Knee Extension Hip Flexion Extra Origin Anterior Inferior Illiac Spine Insertion Patella and Tibial Tuberosity via Patellar Ligament
Adductor Brevis Location – Inside of thigh Movement – Adducts hip. Extras Origin – Anterior surface of inferior pubic ramus, inferior to origin of adductor longus. Insertion – Pectineal line and superior part of medial lip of linea aspera.
Gastrocnemius Location – Posterior lower leg Movement – Plantarflexes foot when knee extended Knee flexion when ankle dorsiflexed Extra Origin – By two heads from medial and lateral condyles of femur. Insertion – Posterior calcaneus via calcaneal tendon.