Biomechanics of thorax
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The document provides details about the biomechanics of the thorax, including its general structures, bones, joints, ligaments, and muscles involved in ventilation. The key structures discussed are the ribs, sternum, thoracic vertebrae, and their articulations. The document describes the types of joints between these structures, including the costovertebral, costotransverse, costochondral, and sternocostal joints. It also summarizes the primary muscles that promote inspiration, such as the diaphragm, intercostals, and scalenes.
Biomechanics of thorax
- 1. BIOMECHANICS OF THORAX PRESENTED BY- RAMANDEEP KAUR SAINI(MPT1)
- 2. THORAX-GENERAL STRUCTURES • THE RIBS-laterally • THORACIC VERTEBRE-posteriorly • STERNUM-anteriorly • Provides a stable base for the muscles attachments of UL,head,neck,Vertebral column and pelvis. • Protection of lungs, heart, viscera • Ventilation
- 3. • The rib cage is a closed chain that involves many joints and muscles. • Superior border-Jugular notch ,1st costocartilages,1st rib and 1st thoracic vertebra. • Inferior border-xiphoid process,costocartilages of 7 -10ribs,inferior portion of 11th and 12th ribs and 12th thoracic vertebra.
- 4. Manubrium • Jugular (suprasternal) notch • Articulation with rib 1 & 2 • Clavicular Articular facets • Sternal Angle – 2 nd rib Body of sternum • Articulates w/ribs 2-7 • Xiphisternal joint Xiphoid process • Cartilage-calcifies through time. • Partial attachment of many muscles THE STERNUM-
- 5. THE RIBS- 12 pairs • 7 True ribs-direct attachment to sternum • 5 False ribs-indirect or no attachment to sternum • Floating ribs- 11th and 12th no ventral attachment. Typical Ribs • Ribs # 2-9 Atypical Ribs • Ribs #1, 10,11,12 Ribs are placed obliquely, upper less oblique than lower. Length increases from Ist to 7th and gradually decreases from 8th to 12th . Reinforce thoracic cage
- 8. ARTICULATIONS OF THE RIB CAGE- The articulations that join the bones of the rib cage are: Manubriosternal (MS), Xiphisternal (XS), Costovertebral (CV), Costotransverse (CT), Costochondral (CC), Chondrosternal (CS), and the Interchondral.
- 9. Manubriosternal and Xiphisternal Joint- • The manubrium and the body of the sternum articulate at MS joint. Also known as the sternal angle or the angle of Louis. Synchondrosis type joint. • Ossification of the MS joint occurs in elderly persons. • The xiphoid process joins the inferior aspect of the sternal body at the XS joint. • The XS joint is also a synchondrosis that tends to ossify by 40 to 50 years of age.
- 10. Costovertebral joint- • The typical CV joint is a synovial joint, 2 through 9. • Formed by head of the rib, two adjacent vertebral bodies, and the interposed intervertebral disk. • Ribs 2 to 9 have typical CV joints, as heads of these ribs have 2 articular facets, or so-called demifacets. • The demifacets are separated by ridge called crest. • Small, oval, and slightly convex demifacets of the ribs are called the superior and inferior costovertebral facets. • Adjacent thoracic vertebrae have facets corresponding to those of the heads of 2-9 ribs that articulates with them.
- 11. LIGAMENTS OF CV JOINT- • Typical CV joint is divided into two cavities by the interosseous or intra- articular ligament. • The radiate ligament has three bands: • superior band, attached to the superior vertebra • intermediate band, attached to the intervertebral disc; and the • inferior band, attached to the inferior vertebra.
- 12. • The atypical CV joints of ribs 1 and 10,11 & 12 are more mobile because the rib head articulates with only one vertebra. • Interosseous ligament is absent in these joints; therefore, have only one cavity. • The radiate ligament is present in these joints, with the superior band still attaching to the superior vertebra. • Both rotation and gliding motions occur at all of the CV joints
- 13. Costotransverse Joint- • The CT joint is a synovial joint. formed by costal tubercle of rib with costal facet on transverse process of the corresponding vertebra. • 10 pairs of CT joints articulates T1 through T10 with the rib of same number. • CT joints on T1-T6 have slightly concave costal facets on the transverse processes and slightly convex costal tubercles on the corresponding ribs. This allows slight rotation movements. • At the CT joints of T7 through T10, both articular surfaces are flat and gliding motions predominate. • Ribs 11 and 12 do not articulate with their respective transverse processes of T11 or T12
- 14. LIGAMENTS- • The CT joint is surrounded by a thin, fibrous capsule. • Three major ligaments support the CT joint capsule . • Lateral costotransverse ligament-a short, stout band located between the lateral portion of the costal tubercle and the tip of the corresponding transverse process. • costotransverse ligament- composed of short fibers that run with in the costotransverse foramen between the neck of the rib posteriorly and the transverse process at the same level. • superior costotransverse ligament-runs from the crest of the neck of the rib to the inferior border of the cranial transverse process.
- 15. COSTOCHONDRAL JOINT AND CHONDROSTERNAL JOINT- • CC joints are formed by articulation of the 1st through 10th ribs anterolaterally with the costal cartilages. • Synchondroses type. • The CC joints have no ligamentous support. • CS joints are formed by the articulation of costal cartilages of ribs 1 to 7 anteriorly with the sternum. • Rib 1 attaches to the lateral facet of the manubrium. • Rib 2 is attached via two demifacets at the manubriosternal junction, • Ribs 3 through 7 articulate with the lateral facets of the sternal body. The CS joints of the 1st, 6th, and 7th ribs are synchondroses. • The CS joints of ribs 2 to 5 are synovial joints.
- 17. LIGAMENTS OF CS JOINT- • Ligamentous support for the capsule includes • anterior and posterior radiate costosternal ligaments. • The sternocostal ligament is an intraarticular ligament, that divides the two demifacets of the 2 nd CS joint. • The CS joints may ossify with aging. • The costoxiphoid ligament connects the anterior and posterior surfaces of the seventh costal cartilage to the front and back of the xiphoid process.
- 18. Interchondral joint- • The 7th to 10th costal cartilages articulate with cartilage above them to form interchondral joints. • For 8th through 10th ribs,articulation is indirectly with sternum. • Interchondral joints are synovial joints and are supported by a capsule and interchondral ligaments. • The interchondral articulations,tend to become fibrous and fuse with age.
- 19. KINEMATICS- Movement of rib cage is a combination of geometry governed by- • Angle of the articulation • Movement of Manubriosternum • Elasticity of the Costal Cartilage
- 20. • There is a single axis of motion for the 1st to 10th ribs through the center of the CV and CT joints. • For upper ribs axis lies close to frontal plane(frontal axis) allowing motion predominantly in sagittal plane. • For lower ribs axis is nearly in sagittal plane(sagittal axis) allowing motion predominantly in the frontal plane. • The axis of motion for the 11th and 12th ribs lies close to frontal plane.
- 21. • During inspiration, the ribs elevate. • In upper ribs, most of movement occurs at anterior aspect of the rib,nearly frontal axis at the vertebrae. • The movement of ribs pushes the sternum ventrally and superiorly. • Less movement occurs at manubrium because first rib is shortest and less mobile. • The motion of upper ribs and sternum has greatest effect by increasing anteroposterior (A-P) diameter of thorax. • This combined rib and sternal motion has been termed as “pumphandle” motion.
- 22. • Elevation of the lower ribs occurs nearly at sagittal axis. • Lower ribs have more angled shape and an indirect attachment anteriorly to sternum. • These factors allow the lower ribs more motion at the lateral aspect of the rib cage. • Elevation of the lower ribs has greater effect to increase the transverse diameter of the lower thorax. • This motion has been termed the “bucket handle” motion of the thorax. • The orientation of the axes of motion from cephalad to caudal is shifting gradually therefore, the intermediate ribs perform both types of motion. • The 11th and 12th ribs do not participate in closed- chain motion of the thorax
- 23. MUSCLES OF VENTILATION- • Primary muscles are recruited for quite ventilation- • Diaphragm • Intercostals (Parasternals) • Scalene • These muscle promote inspiration • There is no muscle for expiration as it is a passive process.
- 24. • Diaphragm- • Accounts for 70-80% of inspiration during quite breathing • Circular set of muscles arises from: Sternum, Costal cartilage, Ribs and Vertebral bodies. • Inserts into central tendon. • Diaphragm muscular portions-dorsal segments arise from vertebral bodies(crural fibers) • Ventral segments arise from sternum and ribs (costal fibres)
- 25. • During tidal breathing,the costal fibres contract ,causing a descent in the dome of diaphragm.The abdominal contents are compressed and increase intra abdominal pressure. • Futher deep inhalation,the abdomen compressed acts to stabilize the central tendon. • With continued contraction of costal fibres,the lower ribs are lifted and rotated outwardly in bucket handle motion. • There is increase in thoracic szie and resultant decreased intrapulmonary pressure. • When active muscle contraction ceases, the domes of diaphragm returns to resting position.The thoracic volume decreases and intrapulmonary pressure increases and exhalation occurs.
- 26. Intercostal muscles-(External & internal) • INTERNAL INTERCOSTAL- arise from a ridge on the inner surfaces of ribs 1-11 • Inserts-sup. Border of the rib below. • Lies deep to the external intercostal muscles and runs caudally & posteriorly to the angle of the ribs(posterior intercostal membrane). • Active during exhalation. • EXTERNAL INTERCOSTAL -arise from inferior orders of ribs 1-11 • Inserts-superior border of the rib below. • Runs caudally and anteriorly at an oblique angle to the internal intercostal muscles.(anterior intercostal membrane) • Active during inspiration
- 27. Scalene muscles- • Arises from transverse process of C3 to C7 and descends to the upper borders of 1st rib(SA,SM) and 2nd rib (SP). • Lifts the first 2 ribs and sternum in pump handle movement of upper rib cage. • Activity begins at onset of inspiration and increases as gets closer to Total lung capacity. • Stabilizer of the rib cage
- 28. ACCESSORY MUSCLES- • Attaches the rib cage to shoulder girdle, head, verterbral column, or pelvis. • Assist with inspiration or expiration in situation of stress. • Accessory muscles of inspiration-increases thoracic diameter moving ribcage upward and outward. • Expiration-moves diaphragm upwards and thorax downward and inward. • Sternocleidomastoid and trapezius -pulls rib cage superiorly expanding in pump handle motion during end of a maximal inspiration. • Pectoralis major, minor and subclavius -helps to raise the upper chest for inspiration • Levatores costarum -runs from transverse process of C7-T11 to posterior external surface of the next lower rib.Assist with elevation of upper ribs.
- 29. • Abdominal muscles-(Transversus abdominis, internal and external oblique abdominis,rectus abdominis)- • Assist with forced expiration but during periods of increased ventilator needs assists in both. • Significant role during inspiration-the increased abdominal pressure created by lowering the diaphragm is countered by tension in abdominal muscles by effectively stabilizing central tendon for expanding lateral chest wall • Also prepares respiratory system for next inspiration by optimizing the length tension relationship of the diaphragm muscle fibres by pushing it cranially during forced exhalation.
- 30. • Transverses thoracis -runs deep to the parasternal muscles originating from the the posterior surface of the caudal half of the sternum • Insert-inner surface of the costal cartilages of rib 3-7 • Recruited along with abdominal muscles to pull the rib cage caudally • Primarily expiratory muscle when it is active as in talking,coughing or laughing or in forced exhalation into functional residual capacity.
- 31. PATHOLOGICAL CHANGES IN COPD- • Damage to airway and destruction of alveolar walls • elastic recoil property diminished • air trapping and hyperinflation • alters lung volumes and capacities leading barrel shape chest with flattening of diaphragm at rest • shortening ,decreased available range of contraction • pull the lower rib cage inward
- 32. RECENT ADVANCES- • A narrative review-Thoracic ultrasound: Potential new tool for physiotherapists in respiratory management. • AUTHORS-Aymeric Le Neindre ,Silvia Mongodi, François Philippart, Bélaïd Bouhemad. • PUBLISHED-Journal of critical care,2016
- 33. • Physiotherapists currently lack accurate, reliable, sensitive, and valid measurements for patient monitoring and assessments of the indications and effectiveness of chest physiotherapy. • Basics of lung US-simple machine with a micro-convex probe of frequency 2-4Mhz. • Longitudinal and transverse view • Modes- B mode(brightness, real time)2D,M mode (motion)
- 34. EFFECT OF MULLIGAN’S MOBILIZATION WITH MOVEMENT ON THORACIC EXPANSION IN COPD PATIENTS- • PUBLISED-Original Research Paper- Physiotherapy of GLOBAL JOURNAL FOR RESEARCH Analysis,April 2018 • AUTHORS-Dr.Poonam Patil, Viraj Dighe • The sample design- 30 subjects with age group 50 to 70 years male and female included diagnosed with COPD were treated by using mulligans MWM. • The study was concluded by pre and post assessment where the subjects were treated for 3 days a week.
- 35. • Pre treatment assessment- incentive spirometer and inch tape measurement of chest expansion. The treatment procedure of Mulligan’s mobilization with movement was performed for intercostal spaces and costochondral joints. • Post treatment assessment was done respectively. The statistical analysis was done by using instat by paired t-test using pre and post interventional data and the results were compared.
- 36. Conclusion: From the above conducted study it concluded that a subject with mulligan’s mobilization with movement on COPD patients has significant improvement clinically and statistically which improved chest expansion and spirometry score. Further studies can be done in order to determine the long term effect of this program and evaluate this COPD Rehabilitation regimen.