Muscles of the Core. PSK 4U Mr. S. Kelly North Grenville DHS

Transcription

1 Muscles of the Core PSK 4U Mr. S. Kelly North Grenville DHS

2 Intercostal Muscles Run between the ribs Provide shape and movement for chest wall External intercostals: aid in both quiet (passive) and forced inhalation Internal intercostals: aid in forced expiration Fibres of internal and external intercostals run in opposite directions

3 Thoracic Cage

4 Serratus Posterior Superior OR: nuchal ligament, spinous processes C7-T3 INS: 2-5 rib (upper border) ACT: elevation of ribs to aid in respiration INN: ventral rami T1-T5

5 Serratus Posterior Inferior Links thoracic and lumbar regions (from a muscular standpoint) Origin: T11-L2, supraspinal ligament Insertion: ribs 9-12 Action: aids in trunk extension and rotation by pulling lower ribs backward and downward; aids forced exhalation Innervation: intercostal T9-T12

6 Quadratus Lumborum Origin: iliolumbar ligament and internal iliac crest Insertion: lower border of last rib, via tendons to transverse processes L1- L4 Innervation: ventral rami T12-L4 Posterior core muscle often referred to as a back muscle

7 QL: function and significance 5 functions/actions: 1. Lateral flexion of vertebral column 2. Extension of L-spine 3. Fixes 12 th rib during forced exhalation 4. Aids diaphragm in inhalation 5. Elevates ilium Common source of low back pain When erector spinae are inhibited/weak as in chronic computer use while seated, QL becomes main support muscle, contracts for longer, weakens, spasms

8 More QL significance When hip adductors become weak or inhibited as part of gait, QL compensates and becomes prime mover. During gait when QL is prime mover, it lifts the ilium (hips) more than is economical/ideal lateral lower back pain Since this is such a consistently used muscle and such a common site for back pain, muscle imbalances, gait issues as diagnosed by physiotherapists can help solve the problem. Other temporary solutions: ice, heat, massage

9 Abdominal Muscles Rectus Abdominis: paired muscles on anterior abdominal wall separated by linea alba (white line) of connective tissue Functions to aid in posture, help respiration, keeps internal organs in place, creates intra-abdominal pressure (ex: when lifting) External oblique: largest, most superficial muscle of lateral anterior abdomen Aids in control of intra-abdominal pressure

10 Core Muscles

11 Superficial Inguinal Ring Forms the superficial opening of the inguinal canal (different contents in men vs. women) In athletic pubalgia (sports hernia) conditions, the ring dilates This can be problematic particularly if contents of the abdominal cavity protrude through the inguinal ring Various muscles of the abdomen and upper leg can be involved in sports hernia to be discussed in injuries unit. At times hernias can be palpated Some require specific treatment or diagnosis by a physician

12 Groin Pain Indicators

13 More abdominal muscles Internal oblique: supports the abdominal wall, aids in forced respiration, increases pressure in abdominal cavity, weak rotator of the trunk (assists this movement) Transversus Abdominis: compresses ribs, compresses internal organs, stabilizes thoracic and pelvic regions Important for back health and stability, core health and stability Nicknamed the corset muscle, braces core during heavy lifts, helps pregnant women deliver children Stabilizes spine when contracted, works with spine stabilizers to allow functional movements

14 Transversus Thoracis Originates on costal cartilage, body of sternum, xiphoid process Inserts on ribs and costal cartilage of ribs 2-6. ALMOST without function BUT: Separates ribs from parietal pleura (lining of chest wall, covers diaphragm), depresses ribs and helps forced expiration by decreasing transverse diameter of thoracic cage

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16 The (Thoracic) Diaphragm Sheet of tissue comprised of muscle and tendon Separates thorax from abdomen When contracting, thoracic cavity volume increases, lungs fill Inn: Phrenic (C3-C5) 3 openings: (Vena Cava (8 letters, T8) Oesophagus (10, T10) Aortic Hiatus (12, T12)