muscle review

Quadriceps (Knee Extensors)

Group of muscles responsible for knee extension. Includes the Rectus Femoris (also flexes the hip), Vastus Lateralis, Vastus Medialis, and Vastus Intermedius.

Rectus Femoris

The only biarticular quad muscle that crosses both the hip and knee; it functions to extend the knee and flex the hip.

Hamstrings (Knee Flexors & Hip Extensors)

Muscles that facilitate knee flexion and hip extension, including Biceps Femoris, Semimembranosus, and Semitendinosus.

Biceps Femoris

Muscle with long and short heads; it assists in knee flexion, lateral rotation of the knee, and hip extension (long head only).

Gluteus Maximus

Primary hip extensor, aiding in external rotation and hip abduction; crucial for movements like squats and sprinting.

Iliopsoas

Composed of the Iliacus and Psoas Major; it serves as the primary hip flexor.

Gastrocnemius

Biarticular muscle involved in ankle plantarflexion and knee flexion.

Soleus

Monoarticular muscle responsible exclusively for ankle plantarflexion.

Pectoralis Major

Muscle involved in shoulder horizontal adduction, internal rotation, and flexion, prominent in exercises like the bench press.

Rotator Cuff Muscles

Includes Supraspinatus (initiates shoulder abduction), Infraspinatus and Teres Minor (external rotation), Subscapularis (internal rotation).

Latissimus Dorsi

Muscle contributing to shoulder extension, adduction, and internal rotation; important for pull-ups and lat pulldowns.

Erector Spinae

Muscle group that extends the trunk and facilitates lateral flexion, maintaining spinal posture during lifts.

Biceps Brachii

Muscle for elbow flexion, forearm supination, and weak shoulder flexion.

Triceps Brachii

Responsible for elbow extension; long head also assists in shoulder extension.