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Logo of brjsmedBritish Journal of Sports MedicineVisit this articleSubmit a manuscriptReceive email alertsContact usBMJ
Br J Sports Med. 2007 May; 41(5): 341–342.
PMCID: PMC2659075


A comparison between clinical assessment and magnetic resonance imaging of acute hamstring injuries

Schneider‐Kolsky ME, Hoving JL, Warren P, et al. Am J Sports Med 2006;34:1008–15

Professor Martin P Schwellnus, University of Cape Town, South Africa

BackgroundMagnetic resonance imaging (MRI) is used by clinicians to confirm the clinical diagnosis and to plan management of the injury. Little information is available to assess how MRI compares with clinical assessment.

Research question/sAre MRI findings useful in determining the duration of rehabilitation following acute hamstring strains?

MethodologySubjects: 58 professional football players with an acute hamstring injury.

Experimental procedure: All subjects underwent a clinical evaluation by an independent physical therapist (<3 days after injury) followed by an MRI. The presence, type and location of injury were recorded in each examination. Time to return to competition was estimated by the physical therapist, and rehabilitation duration was estimated by the radiologist using the length of the injury (coronal view).

Measures of outcome: Relationship between clinical findings and radiological findings.

Main finding/s:

  • Clinical examination (Clin) and MRI findings were strongly correlated with the actual time required to competition (Clin: r  = 0.69, p<0.001; MRI: r  = 0.58, p<0.001).
  • Significant predictors of recovery time were longitudinal length of the injury (p<0.001), cross‐sectional size of the injury (p<0.01), site of injury in biceps femoris (p<0.04) and clinical grading (p<0.001).

Conclusion/sCareful clinical examination can significantly predict duration of rehabilitation in acute mild‐to‐moderate hamstring strains. MRI is not required to estimate the duration of rehabilitation.

Evidence based rating7/10

Clinical interest rating8/10

Type of studyProspective cohort study

Methodological considerationsNo standardisation of rehabilitation treatment

Keywordshamstring injuries, magnetic resonance imaging (MRI), physical therapy, rehabilitation

Cardiorespiratory fitness, macronutrient intake, and the metabolic syndrome: the aerobics center longitudinal study

Finley CE, LaMonte MJ, Waslien CI. J Am Diet Assoc 2006;106:673–9

BackgroundThere is accumulating evidence that increased cardiorespiratory fitness is inversely related to the prevalence of the metabolic syndrome.

Research question/sIs increased cardiorespiratory fitness related to decreased prevalence of the metabolic syndrome when macronutrient intake is adjusted for?

MethodologySubjects: 9007 males and 2826 females who underwent comprehensive medical examination (including a symptom‐limited maximal treadmill exercise test and completed 3‐day dietary records).

Experimental procedure: All subjects were divided into fitness tertiles based on their exercise test results. Metabolic syndrome was defined by the NCEP Adult Treatment Panel III criteria (meeting three or more criteria: abdominal obesity, high triglycerides, low HDL, hypertension, high blood glucose, self‐reported diabetes).

Measures of outcome: Adjusted odds ratio of metabolic syndrome in different fitness tertiles.

Main finding/s:

Adjustment for macronutrient intake and other potential confounding variables did not alter the association between cardiorespiratory fitness and prevalent metabolic syndrome.


  • Increased cardiorespiratory fitness is associated with a decreased prevalence of metabolic syndrome.
  • Advice to patients should be to increase their physical activity to reduce their risk for metabolic syndrome and coronary heart disease.

Evidence based rating 7/10

Clinical interest rating 8/10

Type of study Cross‐sectional study

Methodological considerations Well conducted study, large sample size, no cause effect can be determined

Keywords metabolic syndrome, cardiorespiratory fitness, prevalence, macronutrient intake

The 10‐s maximal sprint. A novel approach to counter an exercise‐mediated fall in glycemia in individuals with type 1 diabetes

Bussau VA, Ferreira LD, Jones TW. Diabetes Care 2006;29:601–6

BackgroundIn patients with type 1 diabetes, exercise of moderate intensity increases the risk of hypoglycaemia during and after exercise. However, 10–15 min of high‐intensity exercise (>80% VO2 max) causes an increase in post‐exercise blood glucose levels, irrespective of their level of glycaemic control.

Research question/sDoes a short maximal sprint counter the rapid fall in blood glucose that is associated with moderate‐intensity exercise in individuals with type 1 diabetes, thereby decreasing the risk of early post‐exercise hypoglycaemia?

MethodologySubjects: 7 males suffering from type 1 (insulin dependent) diabetes mellitus (IDDM).

Experimental procedure: All the subjects injected their normal insulin dose, ate their usual breakfast, and when postprandial blood glucose decreased to ~11 mmol/1, they pedalled at 40% VO2peak for 20 min on a cycle ergometer. Subjects then either rested (control (CON)) or engaged in a maximal 10‐s cycling sprint (sprint trial (SPRINT)) in a counterbalanced order.

Measures of outcome: Blood glucose and free fatty acid concentration, hormones (insulin, catecholamines, growth hormone, cortisol).

Main finding/s:

  • There was a decrease in blood glucose following moderate‐intensity exercise (p<0.05) in both trials.
  • Hormones: in the SPRINT trial, the stabilisation of blood glucose was associated with elevated levels of catecholamines, growth hormone and cortisol.
  • Insulin and free fatty acid responses were similar in the SPRINT and CON trials.

Conclusion/sIn patients with IDDM, moderate‐intensity exercise reduces blood glucose concentration, but if this is immediately followed by a high‐intensity 10‐s maximal sprint, a further fall in blood glucose concentration is attenuated, thereby preventing the risk of post‐exercise hypoglycaemia.

Evidence based rating8/10

Clinical interest rating7/10

Type of studyRandomised controlled clinical trial (laboratory study)

Methodological considerationsWell conducted study

Keywordsdiabetes mellitus, insulin dependent, exercise, hypoglycaemia

Aerosolised hyaluronic acid prevents exercise‐induced bronchoconstriction, suggesting novel hypotheses on the correction of matrix defects in asthma

Petrigni G, Allegra L. Pulm Pharm Ther 2006;19:166–71

BackgroundHyaluronic acid (HA) is a member of the glycosaminoglicans (GAGs), and GAGs have been proven to have anti‐asthmatic properties.

Research question/sDoes pre‐administered aerosol of HA prevent bronchoconstriction following an exercise challenge test in asthmatic patients?

MethodologySubjects: 14 patients with mild bronchial asthma (13–36 yrs, 11 males, 3 females, 12 allergic and 2 non‐allergic).

Experimental procedure: All the subjects underwent two exercise challenge tests (10 min free running) on 2 non‐consecutive days. Saline (placebo (P)) or HA were administered by aerosol, 30 min prior to the beginning of the challenge in a randomised fashion. Lung function tests were performed before and after the challenge.challenge.

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figure sm2007SMU5.f2
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Measures of outcome: FEV1 (% change).

Main finding/s:

There was no significant difference observed in the level of HA protection in subgroups (teenagers, young adults).


  • Hyaluronic acid administered by aerosol prior to an exercise challenge in asthmatic patients significantly reduced the fall in FEV1 post‐exercise, thereby reducing the bronchial hyper‐reactivity following exercise.
  • The possible mechanism of HA could be the prevention of water loss of the airways, but this is speculative.

Evidence based rating 7.5/10

Clinical interest rating 8/10

Type of study Randomised, cross‐over, single‐blind study

Methodological considerations Well conducted study, small sample size

Keywords hyaluronic acid, aerosol, asthma, exercise, bronchoconstriction

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