Muscles of the Trunk Flashcards
Erector Spinae (Sacrospinalis) Origin
Slips of muscle arising from the sacrum. Iliac crest. Spinous and transverse processes of vertebrae. Ribs.
Erector Spinae (Sacrospinalis) Insertion
Ribs. Transvese and spinous processes of vertebrae. Occipital bone.
Erector Spinae (Sacrospinalis) Action
Extends and laterally flexes vertebral column (bending backwards, bending sideways). Helps maintain correct curvature of spine in the erect and sitting positions. Steadies the vertebral column on the pelvis during walking
Erector Spinae (Sacrospinalis) Nerve
Dorsal rami of cervical, thoracic, and lumbar spinal nerves
Erector Spinae (Sacrospinalis) Basic functional movement
Keeps back straight (with correct curvatures). maintains posture.
Erector Spinae (Sacrospinalis) Sports that heavily utilize this muscle
All sports, especially swimming, gymnastics, and wrestling
Erector Spinae (Sacrospinalis) Movements or injuries that may damage these muscles
Lifting without bending the knees or keeping the back erect, or holding the object too far in front of the body
Erector Spinae (Sacrospinalis) Strengthening exercises
Back extensions, Lat pull-downs, Squats, Side bends
Erector Spinae (Sacrospinalis) Self Stretches
- Move towel up back with each set of stretching
2. Pull knees into your chest and up towards you shoulders
Semispinalis capitis, cervicis, thoracis (neck/upper back) Origin
Transverse processes of cervical and thoracic vertebrae, (C1-T10)
Semispinalis capitis, cervicis, thoracis (neck/upper back) Insertion
Between nuchal lines of occipital bone and spibnous processes of the cervical vertebrae and upper four thoracic vertebrae, (C2-T4)
Semispinalis capitis, cervicis, thoracis (neck/upper back) Action
Capitis: Most powerful extensor of the head and assists in rotation.
Cervicis and thoracis: Extends thoracic and cervical parts of vertebral column. Assist in rotation of thoracic and cervical vertebrae.
Semispinalis capitis, cervicis, thoracis (neck/upper back) Nerve
Dorsal Rami of cervical and thoracic spinal nerves.
Semispinalis capitis, cervicis, thoracis (neck/upper back) Basic Functional Movement
Looking up, or turning the head to look behind
Semispinalis capitis, cervicis, thoracis (neck/upper back) Sports that heavily utilize these muscles
Rugby scrums. American football. Wrestling. Swimming
Semispinalis capitis, cervicis, thoracis (neck/upper back) Movements or injuries that may damage these muscles
Whiplash injuries
Semispinalis capitis, cervicis, thoracis (neck/upper back) Strengthening exercise
Back Extension
Semispinalis capitis, cervicis, thoracis (neck/upper back) Self Stretch
Arch your back as if being drawn up by a piece of string (cat/camel stretch)
Splenius capitis and Splenius cervicis (neck/upper back) Origin
Splenius Capitis: Lower part of ligamentum nuchae. Spinous processes of the seventh cervical vertebra, (C7) and upper three or four thoracic vertebrae, (T1-T4)
Spenius Cervicis: Spinous processes of the third to sixth thoracic vertebrae, (T3-T6)
Splenius capitis and Splenius Cervicis (neck/upper back) Insertion
Splenius capitis: Posterior aspect of mastoid process of temporal bone. Lateral part of superior nuchal line, deep to the attachment of the sternocleidomastoideus.
Splenius cervicis: Posterior tubercles of transverse processes of the upper two or three cervical vertebrae, (C1-C3)
Splenius Capitis and Splenius Cervicis (neck/upper back) Action
Acting together: Extend the head and neck
Individually: Laterally flexes neck. Rotates the face to the same side as contracting muscle
Splenius Capitis and Splenius Cervicis (neck/upper back) Nerve
Dorsal rami of middle and lower cervical nerves
Splenius Capitis and Splenius Cervicis (neck/upper back) Basic Functional Movement
Looking up, or turning the head to look behind
Splenius Capitis and Splenius Cervicis (neck/upper back) Sports that heavily utilize these muscles
Rugby scrums. American football. Wrestling, Swimming
Splenius Capitis and Splenius Cervicis (neck/upper back) Movements or injuries that may damage these muscles
Whiplash injuries
Splenius Capitis and Splenius Cervicis (neck/upper back) Common problems when muscle is chronically tight / shortened
Headache and neck pain
Splenius Capitis and Splenius Cervicis (neck/upper back) Strengthening Exercise
Prone body neck extension from chin touch chest to straight neck position.
Splenius Capitis and Splenius Cervicis (neck/upper back) Self Stretch
Stand erect. Drop left shoulder. Tilt head to right side. Repeat on other side
Multifidis (spine) Origin
Posterior surface of sacrum, between the sacral foramina and posterior superior iliac spine. Mamillary processes (posterior borders of superior articular processes) of all lumbar vertebrae. Transverse processes of all thoracic vertebrae. Articular processes of lower four cervical vertebrae
Multifidis (spine) Insertion
Parts insert into spinous process two to four vertebrae superior to origin; overall including spinous processes of all the vertebrae from the fifth lumbar up to the axis (L5 to C2)
Multifidis (spine) Action
Protects vertebral joints from movements made by the more powerful superficial prime movers. Extension, lateral flexion and rotation of vertebral column
Multifidis (spine) Nerve
Dorsal rami of spinal nerves
Multifidis (spine) Basic Functional Movement
Helps maintain good posture and spinal stability during all movements
Multifidis (spine) Movements or injuries that may damage this muscle
Lifting without bending the knees or keeping the back erect, or holding the object too far in front of the body
Rotatores (spine) Origin
Transverse process of each vertebrae
Rotatores (spine) Insertion
Base of spinous process of adjoining vertebrae above
Rotatores (spine) Action
Rotate and assist in extension of vertebral column
Rotatores (spine) Nerve
Dorsal rami of spinal nerves
Rotatores (spine) Basic Functional Movement
Helps maintain good posture and spinal stability during standing, sitting and all movements
Rotatores (spine) Movements or injuries that may damage this muscle
Lifting without bending the knees or keeping the back erect, or holding the object too far in front of the body
External and Internal Intercostals (ribs) Origin
External intercostals: Lower border of a rib.
Internal intercostals: upper border of a rib and costal cartilage
External and Internal Intercostals (ribs) Insertion
External intercostals: Upper border of rib below (fibres run obliquely forwards and downwards
Internal intercostals: Lower border of rib above (fibres run obliquely forward and upwards towards the costal cartilage).
External and Internal Intercostals (ribs) Actions
Muscles contract to stabilize the ribcage during various movements of the trunk. Prevents the intercostal space from bulging out or sucking in during respiration
External and Internal Intercostals (ribs) Nerve
The corresponding intercostal nerves
External and Internal Intercostals (ribs) Sports that heavily utilize these muscles
All very active sports
External and Internal Intercostals (ribs) Common problems when muscles are chronically tight / shortened
Kyphosis (rounded back) and depressed chest.
External and Internal Intercostals (ribs) Strengthening Exercise
Twisting Sit ups
External and Internal Intercostals (ribs) Self Stretch
Lie on back on Stability ball with arms and legs outstretched. Take care if you have back problems. Check with your health professional first.
Diaphragm Origin
Back of xiphoid process (Lower tip of breastbone / sternum). Lower six ribs and their costal cartilages. Upper two or three lumbar vertebrae, (L1-L3).
Diaphragm Insertion
All fibres converge and attach onto a central tendon, i.e. this muscle inserts upon itself
Diaphragm Action
Forms floor of thoracic cavity. Pulls its central tendon downward during inhalation, thereby increasing volume of thoracic cavity.
Diaphragm Nerve
Phrenic nerve (ventral rami), C3, 4, 5
Diaphragm Basic Functional Movement
Produces about 60% of your breathing capacity
Diaphragm Sports that heavily utilize this muscle
All physically demanding sports.
Cremaster (pelvic girdle) Origin
Inguinal ligament
Cremaster (pelvic girdle) Insertion
Public tubercle. Crest of pubis. Sheath of rectus abdominis
Cremaster (pelvic girdle) Action
Pulls testes up from the scrotum towards the body (mainly to regulate the temperature of the testes)
Cremaster (pelvic girdle) Nerve
Genital branch of the genitofemoral nerve, L1, L2
External and Internal Obliques Origin
External oblique: Lower eight ribs.
Internal oblique: Iliac crest. Lateral two-thirds of inguinal ligament. Thoracolumbar fascia (i.e. sheet of connective tissue in lower back)
External and Internal Obliques Insertion
External oblique: Anterior half of iliac crest, and into an abdominal aponeurosis that terminates in the linea alba (a tendinous band extending downwards from the sternum)
Internal oblique: Bottom three or four ribs, and linea alba via aponeurosis
External and Internal Obliques Action
- Spine Flexion
- Spine Rotation
External rotates to the opposite side
Internal rotates to the same side - Abdominal Compression
- External only: Spine Lateral Flexion (slight)
Compresses abdomen, helping to support the abdominal viscera against the pull of gravity. Contraction of one side alone bends the trunk laterally to that side and rotates it to the opposite side
External and Internal Obliques Nerve
External oblique: Ventral rami of thoracic nerves, T5-T12
Internal oblique: Ventral rami of thoracic nerves, T7-T12, ilioinguinal and iliohypogastric nerves
External and Internal Obliques Basic Functional Movement
Ex: Digging with a shovel, raking
External and Internal Obliques Sports that heavily utilize these muscles
External oblique: Gymnastics, Rowing, Rugby
Internal oblique: Golf. Javelin. Pole vault
External and Internal Obliques Common problems when muscles are weak
Injury to lumbar spine because abdominal muscle tone contributes to stability of lumbar spine
External and Internal Obliques Strengthening Exercises
Twisting sit ups Abdominal machine crunch Hanging leg raise Reverse trunk twist Side bends
External and Internal Obliques Self Stretches
- Seated twist in chair
2. Suppine back extension on stability board. Use caution if you have back problems. Check with physician
Transverse Abdominis Origin
Anterior two thirds of iliac crest. Lateral third of inguinal ligament. Costal cartilages of lower six ribs. Thoracolumbar fascia.
Transverse Abdominis Insertion
Linea alba via an abdominal aponeuroses (tendinous band extending between the sternum and pubis). Superior ramus of the pubis
Transverse Abdominis Action
Compresses Abdomen, helping to support the abdominal viscera against the pull of gravity
Transverse Abdominis Nerve
Ventral Rami of Thoracic nerves T7-T12, iliolingual and iliohpogastric nerves
Transverse Abdominis Basic Functional Movement
Important during forced expiration, sneezing and coughing. Helps maintain good posture.
Transverse Abdominis Sports that heavily utilize this muscle
Gymnastics. Seated rowing. Javelin. Pole Vault
Transverse Abdominis Common problems when muscle is weak
Injury to lumbar spine, because abdominal muscle tone contributes to stability of lumbar spine
Transverse Abdominis Strengthening Exercise
Twisting sit ups
Transverse Abdominis Self Stretches
- Suppine back extension on stability ball. Use caution if you have back problems.
- Hanging back extension
- Flat suppine stretch
Rectus Abdominis Origin
Pubic crest and symphysis (front of pubic bone)
Rectus Abdominis Insertion
Xiphoid process (base of sternum). Fifth, sixth, and seventh costal cartilages
Rectus Abdominis Action
Flexes lumbar spine. Depresses ribcage. Stabilizes the pelvis during walking
Rectus Abdominis Nerve
Ventral rami of thoracic nerves, T5-T12
Rectus Abdominis Basic Functional Movement
Initiating getting out of a low chair
Rectus Abdominis Sports that heavily utilize this muscle
All sports
Rectus Abdominis Common problems when muscle is weak
Injury to lumbar spine, because abdominal muscle tone contributes to stability of lumbar spine
Rectus Abdominis Strengthening Exercises
- Sit ups
- Abdominal Machine Crunch
- Reverse Sit-ups
- Hanging leg raises
Rectus Abdominis Self Stretches
Suppine stretch on stability ball. Use caution if you have back problems.
Hanging back extension
Quadratus Lumborum (trunk) Origin
Iliac crest. Iliolumbar ligament (the ligament from the 5th lumbar vertebra to the ilium)
Quadratus Lumborum (trunk) Insertion
Twelfth rib. Transverse processes of upper four lumbar vertebrae. L1-L4
Quadratus Lumborum (trunk) Action
- Spine extension (both)
- Spine hyperextension
- Spine lateral flexion
Laterally flexes vertebral column. Fixes the 12th rib during deep respiration (e.g. helps stabilize the diaphragm for singers exercising voice control). Helps extend lumbar part of vertebral column, and gives it lateral stability.
Quadratus Lumborum (trunk) Nerve
Ventral rami of the subcostal nerve and upper three or four lumbar nerves, T12, L1, L2, L3
Quadratus Lumborum (trunk) Basic Functional Movement
Bending sideways from sitting to pick up an object from the floor.
Quadratus Lumborum (trunk) Sports that heavily utilize this muscle
Gymnastics (pommel horse). Javelin. Tennis serve.
Quadratus Lumborum (trunk) Movements or injuries that may damage this muscle
Bending sideways or lifting from sideways position too quickly
Quadratus Lumborum (trunk) Common problems when muscle is chronically tight / shortened
Referred pain to hip and gluteal area, low back
Quadratus Lumborum (trunk) Strengthening Exercise
Side bends
Quadratus Lumborum (trunk) Self Streches
- Sit in chair. Place towel under left foot. Side bend to left, progressively taking up any slack in towel.
Iliopsoas (psoas major and iliacus) Origin
Psoas Major: Transverse processes of all lumbar vertebrae (L1-L5). Bodies of the twelfth thoracic and all lumbar vertebrae (T12-L5). Intervertebral discs above each lumbar vertebra.
Iliacus: Superior two-thirds of iliac fossa. Anterior ligaments of the lumbosacral and sacroiliac joints.
Iliopsoas (psoas and iliacus) Insertion
Lesser trochanter of femur
Iliopsoas (psoas and iliacus) Action
Main flexor of hip joint (flexes and laterally rotates thigh, as in kicking a football). Acting from its insertion, flexes the trunk, as in sitting up from the supine position
Iliopsoas (psoas and iliacus) Nerve
Psoas Major: Ventral rami of lumbar nerves, L1-L4
Iliacus: Femoral nerve, L(1), 2, 3, 4
Iliopsoas (psoas and iliacus) Basic Functional Movement
Going up a step or walking up an incline
Iliopsoas (psoas and iliacus) Sports that heavily utilize these muscles
Rock-face climbing. Sprinting (maximize stride length). Kicking sports (e.g. soccer to maximize kicking force)
Iliopsoas (psoas and iliacus) Common problems when muscles are chronically tight / shortened
Low back pain due to increase in lumbar curve (lordosis)
Iliopsoas (psoas and iliacus) Strengthening Exercises
Incline sit ups. Hanging leg raises. Multi-hip machine (hip joint flexion)
Iliopsoas (psoas and iliacus) Self Stretch
Left leg forward lunge stance; push right hip forward to stretch right iliopsoas. Keep low back flat and maintain upright posture
Pyramidalis origin
Anterior surface of pubis
Pyramidalis Insertion
Lower portion of the line alba
Pyramidalis Action
Pulls on the line alba
Pyramidalis Nerve
Branch of the subcostal nerve T12