Terminology bank

Glossary

Plain-English definitions of the clinical, rehab and strength-and-conditioning terms and acronyms behind the research. A growing bank — new terms are added as they appear in each week's appraisals.

CI95% Confidence IntervalA range likely to contain the true effect if the study were repeated many times.Absence of Evidence vs Evidence of AbsenceA study finding no effect isn't proof the effect doesn't exist.ACWRAcute:Chronic Workload RatioThis week's training load compared with the recent average.AFTAdvanced Footwear TechnologyRacing shoes with curved carbon plates and lightweight resilient foam that improve running economy.ACLAnterior Cruciate LigamentA key stabilising ligament inside the knee, commonly injured in sport.Anterior drawer testA knee-at-90-degrees test of anterior cruciate laxity.AUCArea Under the CurveA single number summarising how well a test or model discriminates between outcomes.RCRArthroscopic Rotator Cuff RepairKeyhole surgery to reattach torn rotator cuff tendons to the humerus.Ascertainment BiasDistortion from how cases are detected or reported, not their true occurrenceAthlete-ExposureStandardised denominator unit (one athlete in one game/practice) for injury ratesAttrition BiasSystematic error from unequal dropout between study groups.AutoregulationAdjusting training load session-to-session based on the athlete's current readiness.Bankart RepairArthroscopic soft-tissue repair of a torn anteroinferior labrumβBeta CoefficientA number showing how much an outcome changes per one-unit change in a predictor.BFlhBiceps femoris long headThe longer, hip-crossing head of the hamstring muscle biceps femoris.Blinded Outcome AssessmentOutcome measured by an assessor unaware of which treatment the participant received.BlindingKeeping people in a study unaware of who got which treatment.BFRBlood Flow Restriction trainingLight-load training with a cuff partially limiting blood flow to build strength.BFRTBlood Flow Restriction TrainingExercising with a limb cuff that partially restricts blood flow to boost strength/hypertrophy gains at low loads.BMIBody Mass IndexA weight-to-height ratio used as a rough proxy for body fatness.Bodyweight MultiplierLoad lifted expressed as a multiple of the athlete's bodyweight.Case-control studyA study comparing people with a condition to similar people without it, looking backward for exposures.CHNICatastrophic Head and Neck InjurySport-related head/spine injury causing death, permanent disability, or severe transient impairmentCODChange of DirectionA planned, pre-cued shift in running direction, typically tested by cutting or shuttle drills.CPHPChronic Plantar Heel PainPersistent heel pain, often plantar-fasciitis-related, used as a broader diagnostic label.Clinical SignificanceWhether a result is large enough to matter for a patient, not just statistically real.KappaCohen's KappaA statistic that measures agreement between two raters beyond what chance alone would produce.Cohort studyAn observational study tracking a group over time to see who develops an outcome.Comparator armThe group in a trial that the intervention is measured against.CIConfidence IntervalThe plausible range around a study's result.COIConflict of InterestA financial or personal interest that could bias a study's conduct or reporting.ConfounderA third variable that distorts the apparent link between exposure and outcome.ConfoundersOutside factors that muddy whether the studied intervention really caused the result.Confounding by IndicationBias where treatment choice correlates with underlying patient riskControl armThe comparison group in a trial that doesn't receive the intervention being tested.CMJCountermovement JumpA standard vertical jump test of lower-body power and readiness.Cox Proportional Hazards RegressionStatistical model estimating time-to-event risk between groupsCross-sectional studyA study that measures exposure and outcome in a group at one single point in time.DOMSDelayed-Onset Muscle SorenessThe muscle soreness that peaks a day or two after unfamiliar exercise.Descriptive Epidemiological StudyA study that reports the pattern of a health outcome without testing a cause.Detection biasSystematic difference in how outcomes are measured or verified between comparison groups.Diagnostic accuracyHow well a test correctly distinguishes people with a condition from those without it.Diagnostic accuracy studyA study testing how well a test correctly identifies who does or doesn't have a condition.Donor-site morbidityUnwanted after-effects at the site tissue was harvested from for a graft.Dose-responseHow the size or amount of an intervention relates to the size of its effect.Dose-response thresholdThe minimum amount of an intervention needed before a measurable effect appears.Eccentric contractionA muscle producing force while it lengthens — like lowering a weight.EffusionAn abnormal build-up of fluid within or around a joint.EMGElectromyographyA measure of the electrical activity a muscle produces when it works.ExergameVideo game requiring physical movement to play, used as an activity intervention.ER/IRExternal Rotation/Internal RotationRotation of a limb segment away from (ER) or toward (IR) the body's midline.External ValidationTesting whether a study's findings hold up in different people, places, or settings.FWCIField-Weighted Citation ImpactHow often a paper is cited compared with similar papers in its field.FIFA 11+A structured warm-up programme designed to reduce injury risk in footballers.Force plateA device that measures the forces a person exerts as they push against the ground.FMSFundamental Movement SkillsBasic movement patterns like running, jumping, catching, and balancing that underlie sport skill.FMSFundamental Movement SkillsBasic locomotor, object-control, and stability skills underlying children's motor development.GeneralisabilityHow well study findings apply to people or settings beyond the one studied.GeneralizabilityHow well a study's findings apply beyond the sample studied.Glenoid Bone LossErosion or fracture of the anteroinferior glenoid rim after dislocationGPSGPSSatellite tracking units that measure how far and fast athletes move.GRADEA standardised system for rating the certainty of evidence and strength of clinical recommendations.GRFGround Reaction ForceThe force the ground pushes back with when you move on it.HVHallux valgusA deformity where the big toe angles inward toward the second toe.HRHazard RatioRelative rate of an event occurring in one group versus another over timeHeterogeneityHow much results differ across studies in a meta-analysis beyond chance.HSRHigh-Speed RunningDistance covered above a set speed threshold, a key training-load marker.Hop testSingle-leg hop tests used to judge limb symmetry and return-to-sport readiness.Hypothesis-generatingA study designed to suggest ideas for future testing, not to confirm a treatment effect.Hypothesis-generating studyA study designed to suggest ideas for future testing, not to confirm them.IRRIncidence Rate RatioCompares how often an event happens per unit time between two groups.Incorporation biasA diagnostic study is biased when the test being evaluated is also used to help define the diagnosis it's tested against.IMUInertial measurement unitA wearable sensor that measures body movement, acceleration, and orientation.ISISInstability Severity Index ScorePre-operative score predicting recurrence risk after shoulder stabilizationInter-rater reliabilityHow consistently different assessors get the same result when rating the same thing.Interaction effectWhen one variable's effect on the outcome depends on the level of another variable.IKDCInternational Knee Documentation Committee Subjective Knee FormPatient-reported and clinician-rated knee function scoring system.ICCIntraclass Correlation CoefficientA statistic showing how consistent repeated measurements are for the same subject.GLIPF GL PointsIPF's current bodyweight-normalisation formula, successor to the Wilks coefficient.I²I² StatisticPercentage of between-study variability in a meta-analysis due to true heterogeneity.KOOSKnee injury and Osteoarthritis Outcome ScoreMultidimensional patient-reported outcome measure for knee injury/OA.KT-1000 ArthrometerHandheld device quantifying anterior tibial translation in millimetres.Lachman testThe most sensitive manual test for an ACL tear.Latarjet ProcedureCoracoid bone-block transfer for anterior shoulder instabilityLETLateral Extra-Articular TenodesisA soft-tissue procedure added to ACL reconstruction to reduce rotational knee laxity.Lemaire ProcedureNamed lateral extra-articular tenodesis technique using an iliotibial band strip.Leukocyte-Rich vs Leukocyte-Poor PRPPRP subtypes classified by white-cell content, thought to alter clinical effect.Level IV EvidenceA study-quality rating meaning evidence from case series, not controlled comparisons.Level of EvidenceHierarchical grading of study design rigor used to weight clinical evidenceLOPLimb Occlusion PressureThe minimum cuff pressure needed to fully stop arterial blood flow into a limb.LSILimb Symmetry IndexHow the injured limb compares with the uninjured one, as a percentage.Long-Term Athletic DevelopmentA multi-year framework for progressively developing physical capacity and sports skills as young athletes mature.Loss to Follow-upParticipants who drop out of a study before it ends, before outcomes can be measured.LEFSLower Extremity Functional ScaleGeneric patient-reported questionnaire scoring lower-limb function in daily activities.Lysholm Knee Scoring Scale100-point patient-reported knee function questionnaire.MacIntosh ProcedureNamed lateral extra-articular tenodesis technique routing IT band over the LCL.Matched controlsComparison subjects deliberately paired to the study group on key traits.HRmaxMaximal Heart RateThe highest heart rate you can reach during all-out effort.VO2maxMaximal Oxygen UptakeThe most oxygen your body can use during hard exercise.Measurement errorThe gap between a recorded value and the true value it's meant to represent.Mechanical symptomsJoint symptoms like locking, catching, or giving way suggesting a physical structural block.Meta-analysisA statistical pooling of results from multiple similar studies into one combined estimate.MCIDMinimal Clinically Important DifferenceThe smallest change a patient would actually notice or value.Misclassification BiasErrors in categorising exposure, outcome, or diagnosis distort a study's results.Multiple Comparisons CorrectionA statistical adjustment that reduces false-positive findings when many tests are run at once.Narrative reviewAn expert-written summary of a topic without a fixed, reproducible search method.NCCSIRNational Center for Catastrophic Sport Injury ResearchUS registry tracking catastrophic sport injuries since the early 1980sNatural HistoryHow a health condition progresses over time without treatment.Neuromuscular controlHow the nervous system coordinates muscles to produce controlled, efficient movement.NMESNeuromuscular Electrical StimulationElectrical current used to make a muscle contract, often in rehab.Observational studyA study that watches what happens naturally, without the researcher assigning treatments.OROdds ratioA ratio comparing the odds of an outcome between two groups.1RMOne-Repetition MaximumThe most weight you can lift once with good form.OCAOsteochondral Allograft TransplantationTransplantation of donor cartilage-bone graft to repair focal joint defectsOCDOsteochondritis DissecansA joint condition where a piece of bone and cartilage loses blood supply and can separate.OverfittingWhen a statistical model fits its training data's noise, not just its true pattern.P-valueThe probability of seeing a result this extreme if there's really no effect.PROMPatient-Reported Outcome MeasureA questionnaire capturing the patient's own view of their health.PROPatient-Reported OutcomesHealth status or symptom data reported directly by the patient, not measured by a clinician.Peak-Selection FilterUsing each athlete's single best-ever performance rather than one time-point measurement.Performance BiasSystematic differences in care between groups caused by lack of blinding, not the treatment itself.PeriodisationPlanning training in phases to peak at the right time and manage fatigue.PHATPerth Hamstring Assessment ToolPatient-reported outcome measure specific to hamstring injury and function.Pivot shiftA test for the rotational knee instability a torn ACL leaves behind.PRPPlatelet-Rich PlasmaAutologous blood product concentrated for growth factors, used therapeutically.Point EstimateThe single best-guess value for an effect from a study's data.Power calculationA pre-study estimate of how many participants are needed to reliably detect an effect.Propensity MatchingA statistical method that pairs treated and untreated subjects with similar baseline characteristics to mimic randomisation.Prospective cohort studyA study that follows a group forward in time to see who develops an outcome.Prospective studyA study that follows participants forward in time from the start.Proximal Hamstring AvulsionComplete or severe tear of the proximal hamstring tendon(s) off the ischial tuberosity.Psychological readinessA patient's mental preparedness, confidence and fear of re-injury, when returning to sport.Publication BiasStudies with positive or notable results are more likely to get published than null ones.QTQuadriceps Tendon AutograftA knee ligament graft harvested from the patient's own quadriceps tendon.Quantile RegressionRegression modelling relationships at chosen percentiles, not just the mean.RandomisationAssigning participants to study groups purely by chance to avoid bias.RCTRandomised Controlled TrialA study that randomly assigns people to treatments to test cause and effect.ROMRange of MotionHow far a joint can move.RPERate of Perceived ExertionA person's self-rated sense of how hard they are working during exercise.RPERating of Perceived ExertionA self-reported score of how hard exercise feels.Recall biasDistorted study results because participants misremember or selectively report past exposures.Reference standardThe best available test used as the benchmark to judge a new test's accuracy.Regression to the MeanExtreme measurements tend to be followed by less extreme ones on retest, even without any real change.Repeated-measures designA study design where the same participants are measured multiple times under different conditions.Residual confoundingBias remaining after adjustment because confounders were mismeasured, unmeasured, or imperfectly controlled.Retear RateThe proportion of repaired tendons or ligaments that tear again after surgery.Retrospective case seriesA backward-looking review of outcomes in a group of patients who already received the same treatment or diagnosis.Retrospective cohort studyA study that looks back at existing data to compare outcomes between exposed and unexposed groups.Retrospective studyA study that looks back at existing data to examine past exposures and outcomes.RTSReturn to SportThe staged process of getting an athlete back to competition after injury.Return-to-Sport CriteriaBenchmarks an athlete must meet before resuming competitive sport after injury.RTSReturn-to-sport testingTests used to judge whether an athlete is ready to safely resume competitive sport after injury.rCFIReverse Continuous Fragility IndexA fragility-style stability metric computed by removing events instead of adding them.Risk of BiasHow likely a study's design flaws are to have distorted its result.Risk-of-Bias AssessmentA structured check for flaws in a study's design that could distort its results.Risk-of-bias GradingRating how likely a study's methods are to have distorted its results.Risk-of-bias toolsStructured checklists that assess how likely a study's design flaws are to distort its results.Scoping reviewA review that maps the size and scope of existing literature on a topic.Search StrategyThe planned method used to find relevant studies for a review.Selection biasA systematic error from how participants were chosen, not from the intervention itself.Selection on the Outcome VariableAnalysis bias from restricting a dataset using the very outcome being studied.SensitivityThe proportion of people with a condition that a test correctly identifies as positive.Sensitivity AnalysisA check of whether a study's conclusions hold up under different analytic assumptions.sRPESession RPESession load estimated by multiplying perceived effort by duration.SF-36Short Form-36 Health SurveyGeneric health-related quality-of-life questionnaire with physical and mental summary scores.Single Leg ExtensionA unilateral knee-extension exercise or test performed one leg at a time.Single Leg PressA leg press performed one leg at a time to isolate and load each limb independently.SDStandard DeviationA measure of how spread out individual values are around the mean.SMDStandardised Mean DifferenceA way to express how big an effect is, on a common scale.Statistical powerThe probability a study will detect a real effect if one truly exists.Statistical significanceA result unlikely to be due to chance alone, per a chosen probability threshold.S&CStrength and ConditioningTraining designed to build strength, power, and physical capacity for sport or daily function.Subgroup analysisExamining whether treatment effects differ across predefined patient subsets within a study.SBFSuture Button FixationA flexible implant technique that fixes ligament or joint injuries using button-and-suture constructs instead of rigid hardware.Sway Balance SystemSmartphone accelerometer-based balance and cognitive screening tool for concussionSystematic reviewA structured summary of all available studies on a specific question.Tegner Activity ScaleSingle-item 0–10 scale rating sport/work activity level.TendinopathyA persistent, load-related tendon pain and dysfunction.UnderpoweredA study too small to reliably detect the effect it's looking for.Underpowered studyA study too small to reliably detect a real effect if one exists.Velocity LossThe percentage drop in barbell speed during a set, used to gauge fatigue and set effort.VASVisual Analog ScaleA 100mm line patients mark to rate pain or symptom intensity.Vote CountingInvalid meta-analytic shortcut tallying studies as significant vs. not, instead of pooling effects.Wilks CoefficientFormula normalising powerlifting totals for bodyweight to compare lifters.XanthomaLipid-laden skin/tendon nodule classically linked to hypercholesterolemia and tendon pathology.