Links: [Loyola University Medical Education] [UW Online Muscle Atlas for leg muscles]
| Muscles of the head | |
| Synergists in closing the jaw:
masseter - closes jaw temporalis - closes jaw |
Antagonist to those at left:
platysma - opens jaw |
| Synergists in flexing head and neck:
sternocleidomastoid - working as pair flex head and neck |
Antagonists in rotation of head:
sternocleidomastoid - working independently rotate in opposite directions |
| Synergists in extension of head and neck:
splenius capitus - working as a pair extend and rotate head trapezius - upper portion extends head and neck semispinalis capitus - longissimus capitus - |
Antagonists in rotation of head:
splenius capitus - working independently rotate head in opposite directions sternocleidomastoid muscles acting in unison flex the head and neck |
| Synergists in adduction of scapula :
rhomboid major and rhomboid minor - adduct (retract) and fixate scapula trapezius - retracts and fixates scapula levator scapulae - raises and fixates scapula |
Antagonist to those at left:
serratus anterior - abducts (protracts) scapula |
| Synergists in abduction of arm:
supraspinatus - abducts and fixates humerus, stabilizes shoulder as part of rotator cuff. deltoid - abducts humerus |
Antagonists to those at left:
(synergists in adduction and lateral rotation of arm)) infraspinatus - adducts and laterally rotates humerus stabilizes shoulder as part of rotator cuff. teres minor - adducts and laterally rotates humerus stabilizes shoulder as part of rotator cuff. (synergists in adduction and medial rotation of arm) teres major - adducts and medially rotates humerus latissimus dorsi - adducts and medially rotates humerus pectoralis major - adducts and medially rotates humerus subscapularis - adducts and medially rotates humerus stabilizes shoulder as part of rotator cuff. coracobrachialis - weakly flexes and adducts arm |
|
Synergists in flexion of elbow: biceps brachii - flexion of elbow brachialis - flexion of elbow brachioradialis - fixates arm in flexed position for lifting |
Antagonist to those at left:
triceps brachii - extension of elbow |
| Synergists in flexion of wrist:
flexor carpi radialis - flex the wrist on the lateral side flexor carpi ulnaris - flex the wrist on the medial side palmaris longus - flexes wrist |
Antagonists to those at left:
(synergists in extension and abduction of wrist extensor carpi radialis longus - extends and abducts wrist extensor carpi radialis brevis - extends and abducts wrist
|
| extensor digitorum - extends the fingers | Antagonists to that at left:
(synergists in flexion of fingers) |
| Synergists in forced inspiration:
(They expand the ribcage and thorax) |
Antagonist to those at left:
(compresses the thorax) |
| Abdominal Muscles
Synergists in forced expiration: rectus abdominus - flexes trunk internal oblique - rotates trunk, supports abdominal wall external oblique - rotates trunk, supports abdominal wall transverse abdominus - supports abdominal wall Synergists: in flexion of torso: iliopsoas - the psoas major and iliacus- flexes the torso on the thigh or the thigh on the torso. rectus abdominus - flexes trunk |
Back Muscles:
erector spinae - extends trunk, antagonist to rectus abdominus and trunk flexors. quadratus lumborum - unilaterally abducts (laterally flexes) trunk, together extend trunk on hip, stabilizes rib in forced expiration |
| Synergists in flexion of thigh:
iliopsoas - the psoas major and iliacus- flexes the torso on the thigh or the thigh on the torson, as in situps. |
Extensor of Thigh The gluteus maximus - extends and abducts the thigh. Important stabilizer of femur in the abducted position. Important muscle in climbing and running, but not walking Synergists with above in abduction of thigh: gluteus medius - abduction of thigh, important in walking to stabilize leg which is planted gluteus minimus - abduction of thigh piriformis - aids in abduction and stabilization of femur in acetabulum. Synergist in abduction of thigh: tensor fascia latae - also stabilizes knee and thigh Synergists in extension of thigh: See hamstrings below |
| Synergists in adduction of thigh:
adductor magnus - greatest thigh adductor adductor brevis - adducts and flexes the thigh adductor longus - adducts and flexes the thigh gracilis - flexes the knee and adducts the thigh |
|
| Synergists in extension of knee:
Quadriceps |
Antagonists to those at left:
(Synergists in flexion of knee and extension of thigh) Hamstrings flex and laterally rotate the knee, extend hip on thigh semitendinosus -flexes the knee and extends the thigh semimembraneosus - flexes the knee and extends the thigh |
| Anterior Leg: (antagonist of those to right)
tibialis anterior - dorsiflexion and inversion of foot |
Synergists in plantar flexion:
peroneus longus and brevis - everts and plantar flexes foot gastrocnemius -most important plantar flexor soleus - plantar flexes and fixates ankle plantaris - plantar flexes ankle and flexes knee tibialis posterior - plantar flexes and inverts foot. |