1.
- Site: Anterolateral thigh
- Target Muscle: Vastus lateralis
- Origin: Greater trochanter and the lateral lip of linea aspera of the femur
- Insertion: Patella via the quadriceps femoris tendon
- Action: Extension; helps straighten the knee joint
- How to locate? To locate the vastus lateralis in a baby, first, gently place the baby on their back or side. Locate their knee and trace upwards along the outer side of the thigh. Gently press the thigh and there should be firm and slightly raised muscle, which is the vastus lateralis.
2.
- Site: Upper arm
- Target Muscle: Deltoid
- Origin: Clavicle (anterior fibers), acromion of scapula (lateral fibers), spine of scapula (posterior fibers)
- Insertion: Deltoid tuberosity of humerus
- Action: Flex and medially rotate arm at shoulder joint (anterior fibers), abduct arm at shoulder joint (lateral fibers), extend and laterally rotate arm at shoulder joint (posterior fibers)
- How to locate? To locate an elderly's deltoid, palpate the acromion, it is the bony projection at the top of the shoulder blade. From there, trace downwards along the lateral side of the shoulder and feel the muscle. The muscle, which is the deltoid, should feel large and firm.