Commonly referred to as a muscle knot, a trigger point is a tight, painful area within the body’s myofascia (the muscle tissue and connective tissues in and around it).
Trigger points form due to stress or injury. Examples include over training, improper training, sustained weight loading (heavy lifting, carrying babies, etc), poor posture, living a sedentary lifestyle, and emotional stress. They can also form as a side effect of other health conditions like fibromyalgia and plantar fasciitis.
Sometimes trigger points can create aches and pain in another part of the body (called referred pain). For example, a trigger point in side of the shoulder could refer pain up the neck and cause headaches.
Common treatment of trigger points is trigger point therapy (also called myofascial release) in the form of massage or acupuncture aimed at the musculoskeletal system. Massage includes cycles of isolated pressure on the knots followed by release, while trigger point acupuncture involves needling that prompts the affected muscle to involuntarily twitch and release its tension.
Believe it or not, many cases of foot pain are caused by trigger points located in the legs and foot. Things like plantar fasciitis can both cause trigger points as well as irritate trigger points that were already there. Meanwhile, trigger points in the calf muscle could refer pain to the plantar and heel area of the foot.