3 Movements of the Trunk Flexion Rotation Extension

TRUNK FLEXION

TRUNK FLEXION: Rectus Abdominalis O: Crest of Pubis & ligaments covering front of symphysis pubis. I: By «3 portions into cartilages of 5th, 6th & 7th ribs. N: Lower intercostal nerves. Accessory Ms.: Internal Obliques & external obliques (reverse action).

TRUNK FLEXION: ROM In backlying: flex. of thorax on pelvis is possible until scapulae are raised from the table. Motion is mainly at the thoracic spine. Fixation: 1)Reverse action of hip flexor muscles. 2)Weight of legs and pelvis.

TRUNK FLEXION: Rectus Abdominalis Limited ROM if: Tension of the posterior longitudinal ligament, ligamenta flava & interspinal & infraspinal ligaments. Tension of the spinal extensor muscles. Apposition of lower lips of vertebral bodies anteriorly with surfaces of subjacent vertebrae. Compression of intervertebral fibocartilages in front. Contact of lower ribs with abdomen.

Each vertebra is made up of

TRUNK FLEXION: Testing Grade 1-0 Note: observe deviation of umbilicus. Upward movement indicates stronger contraction of upper section muscle, & downward movement, stronger contraction of lower section.

Trunk Rotation: Internal & External Oblique External Oblique: O: 8 digitations from external surfaces & inf. borders of lower 8 ribs. I: Ant. ½ of iliac crest & aponeurosis to pubic tubercle. N: Lower intercostals.

Trunk Rotation: Internal & External Oblique Internal Oblique O: lateral half of upper surface of inguinal ligament, anterior 2/3 of iliac crest. I: Crest of pubis, linea alba, inf. bordres of cartilages of 3 last ribs. N: Lower intercostals.

Trunk Rotation: Int. & Ext. Oblique: ROM ROM in backlying: until scapula on side of forward shoulder is raised from table. Limited by: Tension of annulus fibrosus between vertebrae. Tension of oblique abdominal muscles on side opposite to those being tested. In thoracic area, tension of the costovertebral ligaments. In Lumbar area, interlocking of articular facets. Fixation: Reverse action of hip flexors. Accessory muscles: –Lattissimus Dorsi. –Semispinalis. –Multifidus. –Rotatores –Rectus abdominis (combined trunk rotation & flexion).

Facet joints:

Inter-vertebral disc (IVD):

Trunk Rotation: Int. & Ext. Oblique: Gr. 1 & 0 Note: Observe deviation of umbilicus, which will move towards the strongest quadrant if there is a difference in strength of opposing oblique muscles.

Trunk Extension 5 muscles: Iliocostalis Dorsalis Longissimus dorsi Spinalis dorsi Iliocostalis lumborum Quadratus lumborum Sacrospinalis

Trunk Extension Accessory muscles: Semispinales Rotatores Multifidus. ROM: Thoracic spine extends only to approximately a straight line. Lumbar spine extends freely. Fixation: Contraction of gluteus max. & hamstring muscles. Weight of pelvis & legs. Limitation of ROM: Tension of anterior Longitudinal ligament of spine. Tension of ant. Abdominal Muscles Contact of spinous processes. Contact of inf. articular margins with laminae.

Thoracic Spine