Greater lower extremity joint stiffness may be related to the development of tibial stress fractures in runners. Musculotendinous stiffness is the largest contributor to joint stiffness, but it is unclear what factors contribute to musculotendinous stiffness. The purpose of this study was to compare plantar flexor musculotendinous stiffness, architecture, geometry, and Achilles tendon stiffness between male runners with and without a history of tibial stress fracture. Nineteen healthy runners (age = 21 ± 2.7 years; mass = 68.2 ± 9.3 kg; height = 177.3 ± 6.0 cm) and 19 runners with a history of tibial stress fracture (age = 21 ± 2.9 years; mass = 65.3 ± 6.0 kg; height = 177.2 ± 5.2 cm) were recruited from community running groups and the university’s varsity and club cross-country teams. Plantar flexor musculotendinous stiffness was estimated from the damped frequency of oscillatory motion about the ankle follow perturbation. Ultrasound imaging was used to measure architecture and geometry of the medial gastrocnemius. Dependent variables were compared between groups via one-way ANOVAs. Previously injured runners had greater plantar flexor musculotendinous stiffness (P < .001), greater Achilles tendon stiffness (P = .004), and lesser Achilles tendon elongation (P = .003) during maximal isometric contraction compared with healthy runners. No differences were found in muscle thickness, pennation angle, or fascicle length.
Derek N. Pamukoff and J. Troy Blackburn
Sonia DelBusso and Michael Matheny
fractures were first recognized in the literature in 1970. 1 At that time, navicular stress fractures were thought to be extremely rare, accounting for only 0.7–2.4% of all stress fractures. However, as awareness increased, so did the number of reported incidences of navicular stress fractures. 1 Still
Susan K. Grimston, Jack R. Engsberg, Reinhard Kloiber and David A. Hanley
Increased incidence of stress fracture has been reported for amenorrheic runners, while some studies have reported decreased spinal bone mass in amenorrheic runners. Based on results from these studies, one tends to associate decreased spinal bone mass with an increased risk of stress fracture. The present study compared regional bone mass and external loads during running between six female runners reporting a history of stress fracture (seven tibial and three femoral neck) and eight female runners with no history of stress fracture. Dual photon absorptiometry measures indicated significantly greater spinal (L2-L4) and femoral neck bone mineral density in stress fracture subjects (p<0.05) but no differences between groups for tibial bone density. Normalized forces recorded from Kistler force plates indicated significantly greater vertical propulsive, maximal medial, lateral, and posterior forces for stress fracture subjects during running (p<0.05).
Laurel Wentz, Pei-Yang Liu, Jasminka Z. Ilich and Emily M. Haymes
To compare female runners with and without a history of stress fractures to determine possible predictors of such fractures.
27 female runners (age 18–40 yr) who had had at least 1 stress fracture were matched to a control sample of 32 female runners without a history of stress fractures. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry (iDXA). Subjects answered questionnaires on stress-fracture history, training, menstrual status, and diet.
No significant differences were found in menstrual characteristics, diet and dairy intake, or bone measurements. Weekly servings of milk during middle school significantly predicted BMD at the femur (p = .010), femoral neck (p = .002), Ward’s triangle (p = .014), and femoral shaft (p = .005). Number of menstrual cycles in the previous year predicted femoral-neck BMD (p = .004). Caffeine intake was negatively associated with BMD of the femur (p = .010), femoral neck (p = .003), trochanter (p = .038), and femoral shaft (p = .035). Weekly hours of training were negatively associated with total-body BMD (p = .021), total-body bone mineral content (p = .028), and lumbar-spine BMD (p = .011). Predictors for stress fractures included the number of years running, predominantly running on hard ground, irregular menstrual history, low total-body BMD, and low current dietary calcium intake when controlling for body-mass index (Nagelkerke R 2 = .364).
Servings of milk during middle-school years were positively correlated with hip BMD, although current calcium intake, low BMD, irregular menstrual history, hard training surface, and long history of training duration were the most important predictors of stress fractures.
Susan K. Verscheure and Marc R. Hoefelein
Stress fractures are a common overuse injury among athletes. Repetitive loading during weight bearing causes a broad range of stress reactions, from increased bone remodeling to painful fractures. The literature indicates that such injuries are usually treated conservatively with rest or immobilization, but a more aggressive, surgical approach to treatment of stress fractures has also been reported. This study was designed to identify the factors that influence the decision to treat an athlete surgically or conservatively. An analysis of 28 articles was performed. A cross-tabulation design was used to compare 4 categories with the treatment chosen. The categories included severity, anatomical location, and type of stress fracture, as well as the athletic motivation of the individual. All 4 factors were found to influence the treatment of choice, although it was remarkable that only athletes who demonstrated high athletic motivation were treated surgically.
Nanci S. Guest and Susan I. Barr
High levels of cognitive dietary restraint (CDR) have been associated with subclinical menstrual cycle irregularities and increased cortisol levels, both of which can affect bone mineral density (BMD). Low BMD has been implicated in stress fracture risk. We assessed CDR in female runners (≥ 20 km/wk) with a recent stress fracture (SF) and with no stress fracture history (NSF). A sample of 79 runners (n = 38 SF, 29 ± 5 y; n = 41 NSF, 29 ± 6 y) completed a 3-d food record and questionnaire assessing physical activity, menstrual cycle history, and perceived stress. SF and NSF runners had similar body mass index (21.2 ± 1.8 vs. 22.0 ± 2.5 kg/m2), physical activity (35.7 ± 13.5 vs. 33.4 ± 1.34 km/wk), perceived stress, and dietary intakes. CDR, however, was higher in SF runners (11.0 ± 5.4 vs. 8.4 ± 4.3, P < 0.05). Subclinical menstrual cycle disturbances and increased cortisol levels that are associated with high CDR, might in turn contribute to lowered BMD and increased stress fracture risk.
Michelle A. Sandrey, Yu-Jen Chang and Jean L. McCrory
Lower-extremity stress fractures (SFx) are a common occurrence in both athletes and in the general active population. Of the bones that could be involved, the tibia is most frequently affected. 1 Factors associated with tibial SFx have been reported, 2 – 4 but results have been questionable based
Jennifer J. Mancuso, Kevin M. Guskiewicz and Meredith A. Petschauer
Stress fractures, particularly those in the lower extremity, are disabling and time-consuming injuries commonly seen in athletes. A stress fracture of the posterior talus is rare and presents with signs and symptoms similar to those of soft-tissue injuries in the rear foot. This case study involves a Division-I collegiate female field-hockey athlete who developed a stress reaction in her posterior talus approximately 6 weeks after sustaining a mild eversion ankle sprain. Her chief complaint was pain with forceful plantar flexion during running and cutting. Clinicians must be cautious when an athlete presents with posterior foot pain, being sure to properly assess and rule out differential diagnoses such as tendinitis, os trigonal fracture, and muscle strains. This athlete was able to remain weight bearing during healing, so her rehabilitation protocol allowed for a variety of exercise options.