GENERAL INFORMATION
The innermost intercostal muscles, along with the external and internal intercostal muscles, are found between the ribs and assist in breathing. They are the deepest layer of the intercostal muscles, and consequently, they play a crucial role in the respiratory process.
ORIGIN
The innermost intercostal muscles originate from the internal surface of the ribs. Therefore, their origin points are well-positioned to support their function in rib movement and stabilisation.
INSERTION POINT
They insert onto the superior surface of the rib below. Thus, their insertion points are essential for facilitating rib movement during breathing.
MAJOR ARTERIES
Like the other intercostal muscles, the innermost intercostals are supplied by the intercostal arteries. Consequently, these arteries ensure that the muscles receive adequate blood flow to perform their functions effectively.
NEURAL INNERVATION
The intercostal nerves, which are the anterior rami of the thoracic spinal nerves, innervate these muscles. Therefore, proper nerve function is crucial for the activation and control of the innermost intercostal muscles.
TRIGGER POINT
Similar to the other intercostal muscles, trigger points for these muscles are located between the ribs. Addressing these trigger points through massage or other therapies can alleviate discomfort and improve muscle function.
CONCENTRIC FUNCTION
The concentric function of these muscles is to depress the ribs during forced expiration. Thus, they are essential for adequate exhalation, particularly during strenuous activities.
ECCENTRIC FUNCTION
The eccentric function includes controlling the recoil of the rib cage during inhalation. Consequently, they play a critical role in maintaining stability and control during the inhalation process.
ISOMETRIC FUNCTION
The isometric function of the innermost intercostal muscles is to help maintain the integrity and alignment of the rib cage. Therefore, they provide essential support during various physical activities.
RELATED MUSCLES (SCIENTIFIC NAMES)
- External Intercostal Muscles: Primarily responsible for elevating the ribs during inspiration, these muscles work synergistically with the innermost intercostals to manage rib cage movements effectively.
- Internal Intercostal Muscles: Assist in the active process of expiration by helping to depress the ribs, complementing the contraction of the innermost intercostals for precise respiratory control.
- Diaphragm: Serves as the major muscle of respiration, contracting to expand the thoracic cavity and facilitate air intake, which is critical for effective breathing in conjunction with the innermost intercostals.
- Transversus Thoracis: This muscle plays a supportive role in reducing the thoracic cavity’s volume during forced expiration, aiding the innermost intercostals in managing the rib cage’s internal stability.
- Subcostal Muscles: These muscles have similar functions to the innermost intercostals, supporting deeper rib movements and enhancing the overall mechanics of breathing.
ANTAGONIST MUSCLES
- External Intercostal Muscles: These muscles naturally oppose the innermost intercostals by facilitating rib elevation during inhalation, contrasting with the innermost intercostals’ role in expiration.
COMMON INJURIES
- Intercostal Muscle Strain: This injury can arise from overstretching or sudden stress. It leads to severe pain and restricted movement, which is often exacerbated by deep breathing or coughing.
- Thoracic Outlet Syndrome: This syndrome involves compression of the nerves or blood vessels between the collarbone and the first rib, which can include the intercostal muscles and lead to pain, numbness, or tingling in the shoulders and arms.
EXERCISES
- Deep Breathing maximises lung capacity and activates the innermost intercostal muscles, which are essential for strengthening breathing mechanics.
- Thoracic Expansion Exercises: Specifically designed to increase the elasticity and flexibility of the rib cage, thereby enhancing the respiratory volume and efficiency.
- Rib Mobility Exercises: These exercises target the mobility and stability of the ribs, which are crucial for maintaining healthy respiratory function and preventing injuries.
- Pilates for Breathing: This exercise integrates controlled breathing with movements, focusing on the coordination and strengthening of respiratory and core muscles.
- Resistance Band Exercises: Employ resistance bands to add an external challenge during rib expansion exercises, further strengthening the intercostal muscles.
STRETCHES
- Side Stretches: Effectively elongate the intercostal spaces, allowing for greater rib movement and facilitating easier breathing.
- Chest Stretches: These stretches are vital for opening the anterior thoracic wall, improving the flexibility of the rib cage, and promoting better lung expansion.
- Breathing Exercises with Extended Inhalation: Concentrate on slow, controlled inhalations to stretch the lungs and intercostal muscles, increasing both flexibility and respiratory capacity.
- Yoga Poses for Rib Expansion: Such poses enhance thoracic mobility, which is vital for deep breathing and improving overall respiratory health.
- Foam Roller Thoracic Stretches: Roll along the back while lying on the foam roller to deeply massage the thoracic spine and stretch the rib cage, enhancing flexibility and relieving tension in the intercostal muscles.
These detailed exercises and stretches help significantly improve the function and health of the innermost intercostal muscles. They also promote efficient breathing, enhance thoracic mobility, and prevent respiratory muscle injuries.