General

The “Weakly” Muscle – The Transversus Abdomens (TVA)

ORIGIN: Inner surface of the 7th-12th cartilages of the ribs, the deep layers of the thoracolumbar fascia, the anterior two-thirds of the iliac crest and the lateral one-third of the inguinal ligament. INSERTION: Linea alba, the pubic crest, and the pectinous pubis. ACTION: Rotation, flexion and lateral flexion of the trunk. Most importantly, to increase … Read more

The “Weakly” Muscle – THE TFL

ORIGIN: ASIS (Anterior Superior Iliac Spine) and the anterior part of the iliac crest. If you feel your hip bone in the front, this muscle sits just inferior and lateral to the bony structure. INSERTION: ITB (Iliotibial Band) – Since this muscle does not specifically attach to a bone it is of great interest. This … Read more

The “Weakly” Muscle – The SCM

ORIGIN: The base of the skull near the ear (mastoid process) INSERTION: The collar bone (clavicle) and the breast bone (sternum) ACTION: You have one on both sides of the neck. When acting individually, they will cause rotation of the head to the opposite side and side bending to the same side. When acting together … Read more

The “Weakly” Muscle – The Soleus

ORIGIN: Posterior surface of the proximal fibula and the soleal line of the tibia. INSERTION: Dorsum (front) of the calcaneus via the calcaneal tendon or Achilles Tendon. ACTION: Plantar flexion of the talocrural joint and plantar flexion of the foot. (Toes pointed position) REFERRED PAIN: Interestingly enough, this muscle has a referral point in the … Read more

The “Weakly” Muscle – The Gluteus Maximus

ORIGIN: Fascia of the gluteus medius, the external surface of the ilium behind the posterior gluteal line, the fascia of the erector spinae, the dorsal surface of the sacrum, the lateral margin of the coccyx, and the sacrotuberous ligament. INSERTION: The upper fibers attach to the posterior part of the ITB and the fascia lata. … Read more

The “Weakly” Muscle – The Pronator Teres

ORIGIN: Medial epicondyle of the humerus, coronoid process of the ulna, and the common flexor tendon. INSERTION: Lateral radius distal to the insertion of the supinator muscle. ACTION: Weak flexion of the elbow joint, pronation of the forearm. Pronation is a rotation movement where if your right elbow is bent to 90 degrees with elbow … Read more

The “Weakly” Muscle – The ITB (Iliotibial Band)

ORIGIN: A muscular origin where 25% comes from the TFL and 75% comes from the Glute Max. It courses down the lateral aspect of the thigh and also originates on the ilium (hip crest) INSERTION: The lateral condyle of the tibia. This is the bony projection just inferior to the knee. ACTION: This is a … Read more

The “Weakly” Muscle – The Rhomboid

ORIGIN: Spinous process of the vertebrae T1-T5. (Dead center in your spine just below your neck) INSERTION: Medial margin of the scapula inferior to the scapular spine. (The inside border of your chicken bone) ACTION: Stabilization, retraction, elevation and internal rotation of the scapula. REFERRED PAIN: In the one picture you can see the “X’s.” … Read more

The “Weakly” Muscle – The Gluteus Medius

ORIGIN: External surface of the ilium between the anterior and posterior gluteal lines. If you feel your hip crest and go just inferiorly, you should feel the Glute Med. INSERTION: Lateral surface of the greater trochanter of the femur. The widest part of you hips, where the bone proturdes is your greater trochanter. ACTION: Abduction … Read more