Charlie Horse Anatomy
To better understand muscle cramps, it helps to understand the anatomy of the muscles.
Muscles make up about 40% of total body weight. The human body contains over 300 muscles that provide movement for the entire body.
Examples of major muscles include the:
- de Carvalho M, Swash M. Cramps, muscle pain, and fasciculations: not always benign? Neurology. 2004 Aug 24;63(4):721-3. 
- Diener HC, Dethlefsen U, Dethlefsen-Gruber S, Verbeek P. Effectiveness of quinine in treating muscle cramps: a double-blind, placebo-controlled, parallel-group, multicentre trial. Int J Clin Pract. 2002 May;56(4):243-6. 
- Jansen PH, Veenhuizen KC, Wesseling AI, de Boo T, Verbeek AL. Randomised controlled trial of hydroquinine in muscle cramps. Lancet. 1997 Feb 22;349(9051):528-32.