By Nick Mazzone PT, DPT, CSCS
What is the thoracic spine?
The thoracic spine is the middle portion of the spinal column that connects the neck to the lower back region. It consists of 12 separate segments that serve as connections for the ribs, which protect many vital organs including the heart and lungs.
Why is mobility here so important?
It is vital that you have adequate mobility in this region because of the interdependent relationship it has with the cervical and lumbar spine. If you do not have enough motion in the mid back, the nervous system depends more heavily on the upper and lower spine to make up for that motion. This lack of thoracic mobility can then be a contributor to neck or low back pain.
We need adequate thoracic mobility in order to move our shoulder joints into their natural end ranges of motion. If we do not have enough mobility here, more strain is then placed on the glenohumeral joint (shoulder ball-and-socket joint). In this case, we usually see a compensatory increase in motion at the shoulder joint that may lead to increased pressure or strain on the soft tissue in this region. This may increase the chance of injury over time. It is also important to note that we need enough thoracic mobility when we perform overhead presses at the gym. If we cannot keep our thoracic spine extended to neutral (straight spine; not hunched over), we would have to compensate by extending the lumbar spine (bending low back in backward direction). This could lead to increased pressure on the discs of the lumbar region, especially when we load the exercise with too much weight.
Breathing and rib expansion
We just discussed how each thoracic segment is a connection point for the ribs. This means that adequate thoracic mobility is essential for normal expansion of the ribcage while we breathe. When we take a large inhalation, the thoracic spine extends (segment rotates backwards). This allows the ribs to create more space for the lungs to expand. When we exhale, the thoracic spine flexes in order to return to its resting position (flexion would be rotating forward). If we cannot extend the thoracic spine adequately, it limits the amount of air that can fill the lungs. This is important for regulation of the parasympathetic nervous system as well as the cardiovascular system.
Relationship to legs and lumbar spine during squat
You need normal thoracic extension in order to properly perform loaded lower body movements such as the squat. If you are starting to pick up on the theme of interdependence, you are on the right track here. When you perform a squat with resistance from a barbell at the gym, you are resting the bar on your shoulders. When you do not have adequate thoracic mobility, your center of mass shifts forward. This alters the biomechanics of the entire exercise form the floor to the head and neck. This makes it harder to keep your heels down and keep your buttocks back, which ensures that the load is properly handled by the hips and spine. The lumbar spine would then have to compensate by overextending itself, forcing it to handle more of the load than it normally would have to.
Check out this video that shows 3 simple exercises you can perform to help improve thoracic mobility:
Nick Mazzone received his Doctorate in Physical Therapy from Stony Brook University. He has a strong background in strength and conditioning and aims to bridge the gap between strength training and physical therapy. Nick believes that a lifestyle centered around physical fitness and mental well-being are vital to one’s successes and happiness. For this reason, he educates his patients on pain science and helps empower them and motivate them to reach their goals every day. You can find him at Evolve Physical Therapy in Mill Basin, Brooklyn, NY. To view some of his other content, visit drnickmazzonedpt.wordpress.com.
Main photo retrieved from https://www.t-nation.com/training/tip-improve-thoracic-spine-mobility
Photo of ribs and vital organs retrieved from https://www.britannica.com/science/thoracic-cavity
Photo of neck and low back pain retrieved from http://posturedirect.com/17-exercises-to-improve-your-thoracic-spine/
Photo of overhead mobility retrieved from https://fitnesspainfree.com/the-correct-way-to-mobilize-your-thoracic-spine-with-a-foam-roller/
Photo of squat and thoracic spine position retrieved from https://www.ensomovementculture.com/blog-1/movement-training-for-sports-people-mobility/18/4/2017
Photo of rib expansion during breathing retrieved from https://newgradphysicaltherapy.com/role-breathing-physical-therapy/