Dry needling involves the use of fine acupuncture needles to deactivate myofascial trigger points (TPs) in muscles. TPs are focal, hyper-irritable spots located in a taut band of skeletal muscle.
A trigger point is not considered a muscle spasm as only part of the muscle fibres are contracted, a muscle spasm involves the entire muscle. The spots are painful on compression and can produce referred pain, referred tenderness. As far as Podiatry is concerned the TP’s can occur in the lower leg and refer to the foot or be within the foot.
The exact mechanisms of dry needling are not known, but there are mechanical and biochemical effects. Compared to normal tissue, a higher concentration of chemicals which cause pain can be found in trigger points. When the needle is inserted into a trigger point, it helps to normalize these chemical levels. During this response neurochemicals are released, eg endorphins (reduces our perception of pain) and corticosteroids (regulate the body’s immune response and anti-inflammatory reactions and help the healing process).This helps to release muscle tension and results in decreased pain.
Sometimes the foot or leg will jump or quiver on its own when the needle hits the spot. It’s important to obtain a “ local twitch response” (simply reflexes of the spinal cord) with dry needling as it helps the muscle to relax, relieves the pain and removes muscle inhibition in the lower leg that might have been affecting foot function and can help improve foot flexibility/range of movement. It can be helpful in conditions such as heel pain, plantar fasciosis and shin splints.
It is a generally painless procedure. The bottom of the foot is more sensitive than when needling is used on the legs. Most patients do not feel the insertion of the needle, however the local twitch response can elicit a very brief (less than a second) uncomfortable response. Some patients describe this sensation as a pin-prick or a little electrical shock or feels discomfort similar to an ache or small cramp. These sensations are normal and needed to achieve good results.