Kinesiology 2241A/B Lecture Notes - Lecture 7: Plantaris Muscle, Soleus Muscle, Flexor Digitorum Longus Muscle

• School: Western University
• Department: Kinesiology
• Course: Kinesiology 2241A/B
• Professor: Thomas Richard Jenkyn

Document Summary

Without the upwards rotation of the scapula, the humerus would be limited in it"s range of motion to only what the glenoid fossa allows it to do. Rotating the scapula upwards allows muscles of the rotator cuff to support and pull the humerus upwards, while abducting the scapula ensures the motion occurs along the frontal plane. This way, the humerus can maintain its range of motion in the glenoid fossa, while in different anatomical positions: upward rotation of the scapula causes the glenoid fossa to also rotate upwards. This ultimately enhances the joint"s ability to move, and allows the arm to fully rotate upward. During these movements, there are multiple two-joint muscles involved. The anterior rectus femoris crosses both the hip and knee joints, and allows for hip flexion, as well as knee extension. The posterior semimembranosus and semitendinosus act in these movements to extend the hip while flexing the knee.