The Navy SEAL Physical Fitness Guide - Uniformed Services ...

Figure 12-3. Examples for Treating Painful MuscleCramps in the Calf and Quadricep MusclesCalfQuadricepFracturesA true fracture involves a break or chip in the hard outer surface of the bone. Withfew exceptions, true fractures of the lower extremity require a period of immobilization ina cast and supervised care by a medical officer.Stress fractures differ from true fractures and are most commonly seen in the loadbearingbones of the lower extremities, i.e. pelvis, femur, tibia, fibula and bones of the foot.They are caused by excessive strain on the bone. Bone constantly undergoes remodellingand repair in response to the stress of weight bearing. The repair process is accelerated byrest, and is slowed in times of heavy exercise as with runs, hikes, marches and prolongedtraining. When the breakdown process exceeds the bone's ability to repair itself, a stressfracture may result. As the lower extremity bone becomes weakened, weight bearingactivity, such as running, may cause a vague, achy pain at or near the weakened site. Thefirst symptoms of stress fractures are initially poorly localized and often ignored. Later, asthe process continues, the bone will become tender in a very localized area and will oftenache at night or at rest. Ultimately, if left untreated, continued weight bearing may cause atrue fracture within the weakened area of bone. Physical training factors which increase therisk for stress fractures include:" A change in training surface (grass to asphalt, dirt to concrete).The Navy SEAL Physical Fitness Guide 209