Myofascial Meridians
Myofascial meridians are lines of pull based on western anatomy1. These myofascial meridians depict lines that transmit strain and elastic recoil which act to facilitate movement or create stability through the myofascial system1.
Main lines
There are many lines of pull that one can conceptualize. Anatomy Trains1 outlines 12 main myofascial meridian lines. These are a starting point, but as you become more experienced you should use these rules as a guide when making your own1.
- Superficial Back Line
- Superficial Front line (SFL)
- Lateral line
- Spiral Line
- Arm lines
- Deep Front Arm Line
- Superficial Front Arm Line
- Deep Back Arm Line
- Superficial Back Arm Line
- Functional lines
- Back Functional Line
- Front Functional Line
- Ipsilateral Functional Line
- Deep Front Line
Superficial Back Line
Superficial Front Line
Rules
These rules are important for conceptualizing lines other than the 12 main lines or making lines for “atypical” bodies such as those who experienced strokes, amputations, scoliosis, spinal cord injuries, etc1.
1 Lines have a consistent direction without interruption
The lines or “(train) tracks”1 made of myofascial or connective tissue units (muscles and ligaments) must demonstrate have continuity1. The fascial lines must have consistent direction, running fairly straight or turning gradually1. In passive positions the lines may not have consistent direction, but when tensioned, these lines must be straight1.
Drastic changes in direction, depth, or jumping contraindicate a proposed line.
Drastic changes in direction or depth is highly unlikely1. Any exceptions must have evidence that the line acts across multiple levels1.
‘Jumping’ refers to when a fascial line disconnects and starts somewhere else, which would break continuity1.
Direction
The coracobrachialis and pectoralis minor both insert on the coracoid process and form a myofascial line1. The direction between these two is not continuous when the arm is relaxed at one’s side, but the line becomes continuous with the arm overhead1.
A pulley is not considered a loss of continuity1. For example, the fibular longus muscle sharply curves around the lateral malleolus1. Although this appears that this sharp change in direction would disqualify it from being part of a myofascial line, pulleys are permitted by the rules as long as the fascia makes use of them1.
Depth
Depth is an important consideration when forming fascial lines. Anatomy Trains1 suggests that during embryological development, there is one fascial net which folds upon itself to create multiple fascial planes of varying depths1.
It is unlikely for a fascial line to jump from one depth to the next1. This is important to note, since when drawing a fascial line, some lines seem intuitive, until you analyze the depths of the two units you are trying to connect.
For example, when viewing the anterior torso, it appears that the rectus abdominis connects to the sternal fascia and can be followed superiorly through the infrahyoid muscles, but this is an error1.
The infrahyoid muscles insert on the posterior sternum and connect to the deeper ventral fascia and are part of the Deep Front Line1. Whereas the rectus abdominis and its sternal fascia exist in the superficial plane and continue superiorly through the superficial SCM1.
Intervening planes
An intervening plane refers to a plane of fascia that goes in a different direction1. Even if there are two consecutive lines of fascia running the same direction, if there is an intervening plane between them, then you cannot combine these two into a single myofascial line1.
2 Bones act as line anchors
The myofascial lines are anchored or “tacked down” at bony attachments (“train stations”)1.
The deeper/underlying fibers of the muscle attach to the bone while the superficial fibers of the muscle may connect to the myofascia and continue the myofascial line1.
3 Line interweaving and splitting
The myofascial lines interweave (“joining tracks”) and split (“track diverging”) at locations known as “track switches”1.
Interweaving
For example, the 3 main tracks of the abdomen all begin as one fascia posteriorly at the tranverse processes of the vertebra1. These divide at the lateral raphe into 3 distinct grained layers of the internal obliques, external obliques, and transverse abdominis1. Anteriorly, these 3 layers join as one at the linea alba1.
Switches
A switch occurs when line can diverge into different directions.
For example, the rhomboid line can be followed from the vertebra to the scapula. At the scapula, the fascial line can continue inferiorly and anteriorly through the serratus anterior or continue superolaterally through the infraspinatus and teres minor to the shoulder1.
Roundhouse
A roundhouse refers to when myofascial force vectors meet and/or cross1. The most notable examples are the pubic bone or anterior superior iliac spine (ASIS)1.
4 Poly and Monoarticular muscles
Polyarticular muscles are termed “train expresses” whereas monoarticular muscles are termed “locals”1.
The biceps femoris long head is a polyarticular muscle or an “express” and affects the hip and knee joints1. The adductor magnus and biceps femoris short head are both monoarticular “locals” which lie deep to the BFLH1. The adductor magnus only affects the hip while the BFSH only affects the knee1.
Anatomy trains propose that in normal functioning, monoarticular muscles are primarily used for posture1.
For example, anterior pelvic tilt would be achieved primarily through the release of monoarticular hip flexors (pectineus and iliacus) rather than polyarticular hip flexors (i.e. rectus femoris or sartorius)1.
With this philosophy, chronic elbow flexion is chronic and postural, and our focus should be placed on the monoarticular “locals” rather than the polyarticular “expresses”1. Thus, we would focus our attention on the monoarticular brachialis rather than the polyarticular biceps brachii1.
Summary
- Continuity of the grain of the connective tissue without jumping planes or crossing intervening planes1.
- Note the stations where these myofascial tracks tie down to the underlying tissues. • Note any other tracks that diverge or converge with the line. • Look for underlying single-joint muscles that may affect the working of the line.