Functional anatomy of pectoralis minor muscle
Pectoralis minor?
From: the front surface of 2 or 3-5 ribs
Stop at: coracoid process of scapula
Dominant nerve
Lateral thoracic nerve, medial thoracic nerve and C5-T 1 nerve.
The role of pectoralis minor muscle
→ Close gaze
Protrusion, downward rotation and downward pressure of scapula
(In the neutral position, the range of the hem and push-down functions is very small. )
→ distal fixation
Lift your ribs to help you exhale.
The source of tension in pectoralis minor muscle
In life and work, many people sit in front of the computer every day. Lazy sitting posture makes our body in a bad posture of hunchback in the chest for a long time, which makes the pectoralis minor muscle passively shortened and pulls the scapula forward and downward, resulting in a round shoulder phenomenon.
An important function of pectoralis minor muscle is to lift the ribs to help inhalation (normal inhalation is rarely involved, and strong inhalation is more involved). Due to incorrect posture, the diaphragm drops when inhaling, but the chest cannot be opened and closed outward. In order to ensure the inspiratory volume, only by lifting the ribs upwards can the chest volume become larger, so that more air can enter the lungs and ensure normal inhalation. At this time, pectoralis minor muscles need to participate in rib lifting to help inhale. In the long run, the pectoralis minor becomes extremely nervous. The more nervous you are, the more you will affect your posture.
So pectoralis minor is regarded as a "scapegoat" here, and the real culprit is our bad posture.
Pectoralis minor and scapula
The stability of scapula plays a key role in most movements of thoracic vertebra, thorax, cervical vertebra, shoulder joint, clavicle and upper limbs. Among them, it is important to stabilize the scapula with the four muscles of pectoralis minor-trapezius inferior bundle and rhomboid-serratus muscle. Four muscles bind the scapula to the chest like a "cross" (see the last article "The Ultimate Secret of Eliminating Shoulder Pain"). Among them, due to the extremely unbalanced tension between the pectoralis minor muscle and the lower trapezius muscle bundle (the pectoralis minor muscle is tense, short and strong, and the lower trapezius muscle bundle is elongated and weak), the scapula is easy to be unstable.
Another function of pectoralis minor muscle is to make it rotate downward, but due to tension and shortening, it will limit the upward rotation of scapula, leading to acromioclavicular rhythm disorder and acromion impact.
Pectoralis minor muscle and training effect
The training effect of many fitness coaches is not ideal, which may also be related to the tension of pectoralis minor muscle. In the training process, due to the tension of pectoralis minor, the scapula stretches forward, and the loss of neutral and stable scapula will greatly reduce the training movements involving upper limbs, such as pushing chest, shoulders and pulling back. Please refer to the ultimate secret of shoulder pain. )
Pectoralis minor and aesthetics
As mentioned above, the interaction between bad posture and pectoralis minor makes the round shoulder hunchback posture more and more serious. This posture not only has a great influence on aesthetics, but also greatly reduces temperament, makes people look wretched, and the success rate of falling in love will also be greatly reduced.
Pectoralis minor and brachial plexus
The brachial plexus passes through the deep surface of the pectoralis minor muscle, and the extremely tense pectoralis minor muscle will compress the brachial plexus, resulting in numbness, tingling and muscle weakness in the arm.
solution
1. Stretch the pectoralis minor muscle
2. Manual relaxation of pectoralis minor (three points)
3. Strengthen the training of antagonistic muscles
Improve breathing patterns
Develop a good posture