Anatomy: Planes of Movement and Directional Terms

Anatomical Plane Movements & Directions

• Sagittal plane: flexion
• Frontal plane: abduction, scapular elevation, lateral flexion
• Transverse plane: internal rotation, horizontal abduction, pronation, spinal rotation
• Medial direction: toward the mid-line
• Lateral direction: toward the side
• Superior direction: above
• Inferior direction: below
• Anterior (ventral) direction: front
• Posterior (dorsal) direction: back
• Proximal direction: toward trunk/near origin
• Distal direction: away from trunk/far from origin
• Superficial direction: closer to surface
• Deep direction: away from surface
• Unilateral movement: one side of the body
• Bilateral movement: both sides of the body
• Ipsilateral movement: same side of the body
• Contralateral movement: opposite side of the body

Core Muscle Groups

Triceps Brachii

• Origin: scapula (long head), humerus (medial and lateral head)
• Insertion: ulna, elbow joint
• Action: elbow extension

Biceps Brachii

• Origin: scapula (supraglenoid tubercle-long head, coracoid process-short head)
• Insertion: radial tuberosity
• Action: flexion and supination of the forearm, abduction, adduction, and internal rotation of the arm

Brachialis

• Origin: humerus
• Insertion: ulnar tuberosity
• Action: major elbow flexor, can be isolated with pronation

Pectoralis Major

• Origin: clavicle (clavicular part), sternum, first 7 costal cartilages, sixth rib, aponeurosis of the external oblique
• Insertion: humerus
• Action: shoulder adduction, internal rotation, flexion (via clavicular part), extension (via sternocostal part)

Deltoid

• Origin: clavicle (anterior aspect), acromion process (medial), spine of scapula (posterior)
• Insertion: humerus (deltoid tuberosity)
• Action: shoulder flexion and internal rotation (anterior aspect), abduction (medial), extension and external rotation (posterior)

Latissimus Dorsi

• Origin: spinous processes of T7-T12 vertebrae, lower 3-4 ribs, thoracolumbal fascia, iliac crest
• Insertion: humerus
• Action: shoulder extension, adduction, internal rotation, secondary respiratory muscle, anterior rotation of pelvis

Trapezius

• Origin: occipital bone, nuchal ligament (superior part), spinous processes of T1-T4 (middle), T5-T12 (inferior)
• Insertion: clavicle (superior), acromion (middle), scapular spine (inferior)
• Action: stabilization of scapula, moves scapula medially, rotates externally, scapular/shoulder elevation, depression, stabilization and movement of the head

Gluteus Maximus

• Origin: iliac crest, sacrum, coccyx, thoracolumbal fascia, sacrotuberous ligament
• Insertion: femur (gluteal tuberosity), iliotibial tract
• Action: hip extension, external rotation, abduction (superior fibers), adduction (inferior fibers)

Gluteus Medius and Minimus

• Origin: ilium (lateral surface)
• Insertion: femur (greater trochanter)
• Action: hip abduction, extension, external rotation (dorsal fibers), flexion, internal rotation (ventral fibers), stabilization of the pelvis

Tensor Fascia Latae

• Origin: ilium (iliac spine, iliac crest)
• Insertion: IT band
• Action: hip flexion, abduction, internal rotation, stabilization of the pelvis, assisting in knee flexion and external rotation

Hip Adductors

• Origin: pubis, ischium
• Insertion: femur
• Action: hip adduction, internal and external rotation, extension, flexion

Hamstrings

• Origin: ischial tuberosity
• Insertion: tibia, fibula
• Action: hip extension, knee flexion, assists in internal and external rotation of the femur and lower leg

Quadriceps

• Origin: ilium, femur
• Insertion: tibia
• Action: knee extension, hip flexion, assists in internal and external rotation of the knee

Calves

• Origin: femur
• Insertion: back of the heel via Achilles tendon
• Action: plantar flexion of the foot and ankle

Abdominals

• Origin: pelvis
• Insertion: ribcage (thorax)
• Action: support the trunk, move the trunk, protect the spine, hold organs in place

Erector Spinae

• Origin: thoracic vertebrae (T9-T12), ilium (iliac crest)
• Insertion: T1-T2, cervical vertebrae
• Action: movement of the vertebral column (extension, lateral flexion)