A brief discussion on the arm line of the anatomical train
As a whole-body tension network, fascia supports the structural and functional continuity between soft and hard tissues of the body. It participates in, supports, separates, connects, divides, and wraps other tissues. It plays an important role in the transmission of mechanical force between structures. effect.
No matter how the muscle works, it will always have an impact on the overall continuity through the fascial network [1]. Fascia is a previously forgotten element in flexibility and stability. Whether it is central nervous system injury, sports injury, or peripheral nerve injury, flexibility and stability problems may occur. Understand the characteristics of fascia and its impact on injuries and stability. Physiological responses to training and manual interventions are important for lasting and substantial changes in therapeutic effects.
In the theoretical system of fascia, Thomas W. Myers summarized the traceable myofascial "meridians" in the films and lines that run vertically and horizontally through the connective tissue of the body, and summarized the myofascial "meridians" used in manual and movement therapy. warp.
Extend your arms with your palms down and your olecranon toward your back. A. The deep anterobrachial line lines the anterior side - thenar, radius, biceps brachii, and pectoralis minor. D. The deep posterior arm line runs along the back of the arm - the hypothenar, ulna, triceps brachii, rotator cuff muscles, as well as the rhomboids and levator scapulae muscles.
Abduct the arm, with the palm facing forward and the olecranon facing the ground. B. The front line of the arm is arranged along the front of the arm - the palmar muscle group, the forearm flexor muscle group, the intermuscular septum and the pectoralis major muscle. C. The posterior surface line of the arm is arranged along the back of the arm - the trapezius, deltoid, lateral intermuscular space and extensor muscle groups.
Here we focus on the deep line in front of the arm. The deep line in front of the arm mainly controls the angle and grasping ability of the hand through the thumb during open chain movements. The thumb accounts for 40% of hand functions and is used frequently. In daily life, the arm moves forward much more than backward and upward. This fascia line is relatively easy to shorten.
The proximal end of the deep anterior arm line starts from the pectoralis minor complex in front of the 3rd, 4th, and 5th ribs, including the pectoralis minor and subclavian muscles, and is connected to the neurovascular bundle and lymphoid tissue there. The pectoralis minor is the primary contractile tissue that provides support to the scapula, while the smaller subclavius also stabilizes the clavicle. Then distally are the coracoid process, the short head of the biceps brachii starting from the coracoid process, and the coracobrachialis muscle. There are clear myofascial connections between the pectoralis minor and these distal muscles as shown in the image below. When the arm is abducted horizontally or in a higher position, especially in the hanging position, these myofascial units are connected in a line. When the arm droops, the proximal pectoralis minor muscle in the deep line in front of the arm is prone to shortening.
Functional shortening of the pectoralis minor muscle has three characteristics: ① The movement of the upper ribs is restricted during inhalation, ② The patient has difficulty bending the arms and raising the shoulders to reach objects upwards, and ③ the scapula is tilted forward or rounded.
If the shoulders are rounded (excessive internal rotation or excessive protraction of the scapula), one of the important factors is that the shortened pectoralis minor pulls the coracoid process inward and tilts the scapula. The key point of the relaxation technique for the shortened pectoralis minor is that it is easier to start from the armpits and slide along the ribs than through the pectoralis major.
When self-stretching, the patient can interlace his fingers on the lower back and stretch in the direction of the lower limbs. At this time, the shoulder blades will be pulled downwards and the chest will be closer to the spine at the same time. This action will stretch the pectoralis minor and other surrounding tissues, but be careful when doing this. Don't arch your lower back during the movement, otherwise it will change the angle of the chest and offset the stretching effect.
You can also choose to stretch one side against the wall, bend your elbow 90°-120° against the wall, and move your body slightly forward to feel the stretch of the pectoralis minor.
