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Activity levels as a risk factor to lower limb stress fractures

Three Part Question

In [patients with below knee bony pain] are [current levels of activity or previous levels of
activity] a [greater risk factor for lower limb stress fractures]

Clinical Scenario

A 24 year old female presents to the emergency department with atraumatic bony pain in her left foot. She tells you that she is a keen runner and is in the process of training for a marathon. You wonder if her previous activity levels or current increase in activity are a greater risk factor for a stress fracture.

Search Strategy

Ovid MEDLINE(R) 1946 to July Week 1 2015

(exp Tibia/ OR exp Fibula/ OR lower OR exp Lower extremity/ OR exp Foot/ OR exp Foot Bones/) AND (exp Fractures, Stress/ OR exp Athletics Injuries/ OR fatigue OR stress ) AND (exp Exercise/ OR exp Physical Fitness/ OR physical AND (exp Risk Factors/) Limit (English language AND humans AND all adults (19 plus))

Search Outcome

24 Hits and 11 Relevancies

Relevant Paper(s)

Author, date and country Patient group Study type (level of evidence) Outcomes Key results Study Weaknesses
200 Recreational runnersProspective cohort study to determine two factors, What is the incidence of running related injuries and what factors contribute towards this.Level of activity relevant risk factorMinimal impact 1.01 probabilityLow follow up levels Only 12 weeks of review Simple methodology.
High impact training1.46 probability of stress fracture
35 Dutch Male military recruits Case-control study to assess risk factors for MTSS and prognostic factorsRisk factor for stress fractureBMI significant riskPoor description of methodology Small population group Assessed MTSS not stress fractures Aimed to assess risk factors but very specific measurements/only measured physical internal risk factors not external risk factors. No intervention
New Zealand
199 masters level football players ages 40-49 yearsDescriptive cross-sectional study in order to profile training habits and related injuries in football playersActivity acted as a risk factor1-4 hours of training per week risk factorNot related to running Didn’t define what the injuries were Didn’t have a follow up Poor methodology
Number of lower limb stress fractures64 injuries/100 players 67.3% occurred during games
146 healthy collegiate athletesDescriptive cross-sectional study to assess risk factors for MTSSActivity levels relevant risk factorControl = 8.8 years/ 26.5 miles per week MTSS = 5.3 years/ 27.1 miles per weekFocused on intrinsic factors not extrinsic factors in methodology yet mentioned in results No focus on athletics activity Poor follow up
Van middelkoop
1500 recreational runners 694 responded to questionnaire Questionnaire based descriptive cross-sectional study to identify risk factors for lower extremity injuries in runnersActivity levels relevant risk factorRunning less than 40km per week was protective >60 km per week = 21.3% Number of races participated in 0-3 = 0.39 p-value/ >11 = 0.08 p-valueLarge study design may limit specifics of study
Van Gent
Review articleTo present an overview of published reports describing the incidence of various running injuries of the lower extremitiesActivity levels relevant risk factorTraining frequency was a significant risk factor of overall injury RR=3.68 Increase of training of 1d/w also had OR = 1.19 Distance had an increased risk of lower limb injuries between OR= 1.6- 7.4No clear focus aims of study Looked at overall injuries not specific injuries and did not clarify these
49 Runners 25 control and 24 who had injuries Controlled Trial with 3 aims 1. To compare kinetic symmetry in healthy runners 2. compare kinetic SI values between runners who have 1 injury 3. Compare affected to unaffected leg kinetic values Activity levels relevant risk factor104 monthly miles in control group 115 monthly miles in group with Tibial Stress Fracture Speed relevant 3.7m/s in control group 3.8m/s in TSF groupRunning not relevant to subject aims
2962 female Marine Corps recruits Cohort Study to identify risk factors for stress fractures at boot camps.Activity levels relevant risk factorLow aerobic fitness and no menses in past year significantly increased risk factors Slowest time AOR = 3.54%Didn’t explain times of aerobic fitness Not accurate measurements
40 runners- 16 female and 24 male divided into 2 groups Cohort study to identify biomechanical and anthropometric variables that contribute to overuse injuries in runnersRisk factor for stress fractureBiomechanical factors more significant than external factorsSmall population size Not much follow up
Activity levels relevant risk factorNo
136 male military recruitsCohort study to examine the effects of pre-induction strength and fitness levels on the incidence of lower extremity overuse injuriesActivity levels relevant risk factor58.8% participated in no physical conditioning prior to training in this group 11% received stress fractures Compared with the physical active group only 7% suffered stress fractures Those who had competitive sports background suffered no fracturesUnable to access tables of data Good study design Poor follow up Relatively small sample size No clear definition of aerobic fitness
127 female soldiers: 78 control/ 49 confirmed stress fracture Case control study to identify characteristic and factors associated with increased risk for stress fractures in military womenActivity levels relevant risk factorLeisure activity energy expenditure (kcal/day) tended toward association with lower stress fracture risk as expenditure level increased (p=0.06)Full text not available Self-reporting may not be accurate


10 Studies discussed the link between exercise and an increased risk of lower limb stress fractures Of these 10 2 stated that exercise activity was of no or little statistical significance 4 suggested that increased exercise was protective 4 suggested that consistent low levels of exercise were protective All suggested that acute short term increases in exercise were likely to increase risk All suggested that previous injury to the lower limb was a significant risk factor 2 studies suggested that BMI was the current most dangerous risk factor.

Clinical Bottom Line

Acute episodes of increased activity, such as training for upcoming races or major competitions produce the most significant risk factor for potential lower limb stress fractures.


  1. Hespanhol Junior LC Previous injuries and some training characteristics predict running-related injuries in recreational runners: a prospective cohort study. Journal of Physiotherapy 2013 Dec; 263-9,
  2. Moen MH Risk factors and prognostic indicators for medial tibial stress syndrome. Scandinavian Journal of Medicine & Science in Sports 2012 Feb; 34-9:
  3. Newsham-West R Training habits and injuries of masters' level football players: a preliminary report. Physical Therapy in Sport 2009 May; 63-6:
  4. Hubbard TJ Contributing factors to medial tibial stress syndrome: a prospective investigation. Medicine & Science in Sports & Exercise. 2009 Mar; 490-6:
  5. Marienke Van Middelkoop Risk factors for lower extremity injuries among male marathon runners Scandinavian Journal of Medicine & Science in Sports 2008 Dec; 691-7:
  6. Bobbie RN van Gent Incidence and determinants of lower extremity running injuries in long distance runners: a systematic review British journal of sports medicine 2007 Aug; 469-80:
  7. Rebecca Avrin Zifchock Kinetic asymmetry in female runners with and without retrospective tibial stress fractures Journal of biomechanics 2006; 2792-7:
  8. Richard A. Shaffer Predictors of Stress Fracture Susceptibility in Young Female Recruits American Journal of Sports Medicine 2006 Jan; 108-15:
  9. ALAN Hreljac Evaluation of lower extremity overuse injury potential in runners Medicine and science in sports and exercise 2000 Sep; 1635-41:
  10. Jay R Hoffman The effect of leg strength on the incidence of lower extremity overuse injuries during military training Military medicine 1999 Feb; 153-6:
  11. Alana D Cline Stress fractures in female army recruits: implications of bone density, calcium intake, and exercise Journal of the American College of Nutrition 1998 Apr; 128-35,