GENERAL INFORMATION
The internal intercostal muscles are one of the three layers of muscles in the intercostal spaces, located between the ribs, deep into the external intercostals. They aid in the mechanical aspect of breathing, specifically in forced expiration. Consequently, these muscles play a crucial role in the respiratory process.
ORIGIN
The internal intercostal muscles originate from the lateral edge of the costal groove of the rib above. Therefore, their origin points are well-positioned to support their function in rib movement and stabilisation.
INSERTION POINT
They are inserted into the superior border of the rib below. Thus, their insertion points are essential for facilitating rib movement during breathing.
MAJOR ARTERIES
The intercostal arteries supply these muscles. They are a group of arteries running along the costal groove of the rib below the respective intercostal space. Consequently, these arteries ensure that the muscles receive adequate blood flow to perform their functions effectively.
NEURAL INNERVATION
These muscles are innervated by the intercostal nerves, which are the anterior rami of the thoracic spinal nerves. Therefore, proper nerve function is crucial for the activation and control of the internal intercostal muscles.
TRIGGER POINT
Trigger points for these muscles can generally be found along the spaces between the ribs. Pain can often be felt in the chest and upper back region. 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, aiding in the process of breathing. Thus, they are essential for adequate exhalation, particularly during strenuous activities.
ECCENTRIC FUNCTION
These muscles control the return of the rib cage to its resting state during inhalation. Consequently, they play a critical role in maintaining stability and control during the inhalation process.
ISOMETRIC FUNCTION
The isometric function of the internal intercostal muscles is to maintain the spacing and alignment of the ribs. Therefore, they provide essential support during various physical activities.
RELATED MUSCLES (SCIENTIFIC NAMES)
- External Intercostal Muscles: These work in conjunction with the internal intercostals to assist in elevating the ribs during inhalation.
- Innermost Intercostal Muscles: Located just deep into the internal intercostals, these muscles also assist in forced exhalation.
- Diaphragm: The primary muscle for inhalation, closely interacting with the intercostals to control the pressure within the thoracic cavity.
- Transversus Thoracis: Helps depress the ribs during exhalation, supporting the actions of the internal intercostals.
- Subcostal Muscles: Similar in function to the intercostals, located on the lower ribs, aiding in rib movement and thoracic stability.
ANTAGONIST MUSCLES
- External Intercostal Muscles: Functionally antagonistic to the internal intercostals during the respiratory cycle by facilitating rib elevation during inspiration.
COMMON INJURIES
- Intercostal Muscle Strain: This is often caused by repetitive motion or sudden exertion and leads to pain and restricted movement.
- Thoracic Outlet Syndrome: Compression of nerves or blood vessels near the chest, often involving the muscles of the thoracic outlet, including the internal intercostals.
EXERCISES
- Deep Breathing: This exercise targets the expansion of the lungs and strengthens the intercostal muscles by encouraging a fuller range of rib motion.
- Thoracic Expansion Exercises: Focus on increasing the elasticity and flexibility of the rib cage, thereby enhancing the respiratory volume and efficiency.
- Rib Mobility Exercises: These are designed to improve the mobility and flexibility of the ribs, which are crucial for maintaining healthy respiratory function.
- Controlled Breathing Techniques: Utilize specific patterns to challenge and strengthen the respiratory system, including the internal intercostals.
- Pilates for the Core and Chest: This exercise incorporates movements that enhance core stability while also focusing on expanding and contracting the chest cavity.
STRETCHES
- Side Stretches: Effectively elongate the intercostal spaces, allowing for greater rib movement and facilitating easier breathing.
- Chest Stretching: This opens up the anterior thoracic wall, improving the flexibility of the rib cage and promoting better lung expansion.
- Breathing Exercises with Extended Inhalation: Focus on slow, controlled inhalations to stretch the thoracic cavity and strengthen respiratory muscles.
- Yoga Poses for Rib Expansion: Use poses designed to enhance thoracic mobility, which is vital for deep breathing and improving overall respiratory health.
- Foam Roller Thoracic Stretches: Rolling the back and sides along a foam roller stimulates the muscles between the ribs, promoting elasticity and reducing soreness.
These exercises and stretches help significantly improve the function and health of the internal intercostal muscles, promoting efficient breathing, enhanced thoracic mobility, and preventing respiratory muscle injuries. Incorporating these practices into a daily routine can lead to better respiratory health and improved physical performance.