Sep
5
2023
The taut band and other mysteries of the trigger point: An examination of the mechanisms relevant to the development and maintenance of the trigger point
Author(s): Gerwin RD (Gerwin, Robert D.)1,2
Source: JOURNAL OF MUSCULOSKELETAL PAIN Volume: 16 Issue: 1-2 Pages: 115-121 Published: 2008
Objective: To examine the mechanisms that underlie the development of the myofascial trigger point [TrP].
Results: The TrP represents chronically dysfunctional muscle, but initiation and persistence of the TrP taut band have not been fully explained. Studies suggest that the initiating factors are excessive mechanical forces generated by muscle. Supramaximal muscle contraction, overloaded eccentric contraction, or repetitive activity are consistent with Simons’ hypothesis of an energy crisis as a critical event. Ischemia, hypoxia, and cell damage occur, leading to the release of cytokines, bradykinin, substance P, and calcitonin-gene-related peptide, all of which activate peripheral nociceptors. The taut band, chronically contracted, displays a sympathetic nervous system [SNS] modulated, localized, excessive endplate potential activity that produces a localized, nonpropagated contraction. The net effect is an excess of acetylcholine [ACh] at the motor end plate. This results from a combination of excess spontaneous release of ACh modulated by calcitonin-gene-related peptide and the SNS, inhibition of acetylcholinesterase, and upregulation of ACh receptors in the endplate zone. Postsynaptic events in the muscle cell that promote prolonged contraction are those that increase the concentration of calcium in the cytosol. Excessive release of calcium from the sarcoplasmic reticulum through a dysfunctional Ryanidine Receptor calcium channel, by a second messenger system mediated by the SNS, or by mitochondria. could result in persistent muscle fiber contraction.
Conclusion: Pre- and postsynaptic modulation of ACh release and intracellular Ca2+ can explain many of the features of the TrP.
Sep
5
2023
Podiatrist Emily Splichal talks about posture and stiletto.
According to Mayo Clinic these are the conditions that can be casued by wearing high heels shoes:
- Corns and calluses. Thick, hardened layers of skin develop in areas of friction between your shoe and your foot. Painful rubbing can occur from wearing a high heel that slides your foot forward in your shoe or from a too-narrow toe box that creates uncomfortable pressure points on your foot.
- Toenail problems. Constant pressure on your toes and nail beds from being forced against the front of your shoe by a high heel can lead to nail fungus and ingrown toenails.
- Hammertoe. When your toes are forced against the front of your shoe, an unnatural bending of your toes results. This can lead to hammertoe — a deformity in which the toe curls at the middle joint. Your toes may press against the top of the toe box of your shoe, causing pain and pressure.
- Bunions. Tightfitting shoes may worsen bunions — bony bumps that form on the joint at the base of your big toe. Bunions can also occur on the joint of your little toe (bunionettes). Experts disagree on whether tightfitting, pointy-toed, high-heeled shoes cause bunions or bunionettes, but such shoes can exacerbate an already existing problem.
- Tight heel cords. If you wear high heels all the time, you risk tightening and shortening your Achilles tendon — the strong, fibrous cord that connects your calf muscle to your heel bone. Your Achilles tendon helps you point your foot downward, rise on your toes and push off as you walk. Wearing high heels prevents your heel bones from regularly coming in contact with the ground, which in turn keeps your Achilles tendon from fully stretching. Over time, your Achilles tendons contract to the point that you no longer feel comfortable wearing flat shoes.
- Pump bump. Also known as Haglund’s deformity, this bony enlargement on the back of your heel can become aggravated by the rigid backs or straps of high heels. Redness, pain and inflammation of the soft tissues surrounding the pump bump result. Heredity may play a role in developing Haglund’s deformity, but wearing high heels can worsen the condition.
- Neuromas. A growth of nerve tissue — known as Morton’s neuroma or plantar neuroma — can occur in your foot, most commonly between your third and fourth toes, as a result of wearing tightfitting shoes. A neuroma causes sharp, burning pain in the ball of your foot accompanied by stinging or numbness in your toes.
- Joint pain in the ball of the foot (metatarsalgia). High heels cause you to shift more weight to the ball of your foot, rather than distributing your weight over the entire foot. This causes increased pressure, strain and pain in your forefoot. Shoes with tightfitting toe boxes can lead to similar discomfort.
- Stress fractures. Tiny cracks in one of the bones of your foot — stress fractures — may result from the pressure high heels place on your forefoot.
http://www.mayoclinic.com/health/foot-problems/WO00114
