Christopher Napier

Validation of the Fitbit One activity monitor device during treadmill walking

OBJECTIVES In order to quantify the effects of physical activity such as walking on chronic disease, accurate measurement of physical activity is needed. The objective of this study was to determine the validity and reliability of a new activity monitor, the Fitbit One, in a population of healthy adults. DESIGN Cross-sectional study. METHODS Thirty healthy adults ambulated at 5 different speeds (0.90, 1.12, 1.33, 1.54, 1.78 m/s) on a treadmill while wearing three Fitbit One activity monitors (two on the hips and one in the pocket). The order of each speed condition was randomized. Fitbit One step count output was compared to observer counts and distance output was compared to the calibrated treadmill output. Two-way repeated measures ANOVA, concordance correlation coefficients, and Bland and Altman plots were used to assess validity and intra-class correlation coefficients (ICC) were used to assess reliability. RESULTS No significant differences were noted between Fitbit One step count outputs and observer counts, and concordance was substantial (0.97-1.00). Inter-device reliability of the step count was high for all walking speeds (ICC ≥ 0.95). Percent relative error was less than 1.3%. The distance output of the Fitbit One activity monitors was significantly different from the criterion values for each monitor at all speeds (P<0.001) and exhibited poor concordance (0.0-0.05). Inter-device reliability was excellent for all treadmill speeds (ICC ≥ 0.90). Percent relative error was high (up to 39.6%). CONCLUSIONS The Fitbit One activity monitors are valid and reliable devices for measuring step counts in healthy young adults. The distance output of the monitors is inaccurate and should be noted with caution.

Gait modifications to change lower extremity gait biomechanics in runners: a systematic review

Background Abnormal biomechanics have been cited as a potential risk factor for running-related injury. Many modifiable biomechanical risk factors have also been proposed in the literature as interventions via gait retraining. Aim To determine which interventions have successfully modified biomechanical variables linked to running-related injury. Study design Systematic literature review. Methods MEDLINE, EMBASE, CINAHL, SportDiscus and PSYCINFO were searched using key terms related to running biomechanics and gait retraining. Quality of included studies was assessed using the modified Downs and Black Quality Index and a best evidence synthesis was performed. Results 27 studies investigating the effect of biomechanical interventions on kinetic, kinematic and spatiotemporal variables were included in this review. Foot strike manipulation had the greatest effect on kinematic measures (conflicting evidence for proximal joint angles; strong evidence for distal joint angles), real-time feedback had the greatest effect on kinetic measures (ranging from conflicting to strong evidence), and combined training protocols had the greatest effect on spatiotemporal measures (limited to moderate evidence). Conclusions Overall, this systematic review shows that many biomechanical parameters can be altered by running modification training programmes. These interventions result in short term small to large effects on kinetic, kinematic and spatiotemporal outcomes during running. In general, runners tend to employ a distal strategy of gait modification unless given specific cues. The most effective strategy for reducing high-risk factors for running-related injury—such as impact loading—was through real-time feedback of kinetics and/or kinematics.

Gait retraining: out of the lab and onto the streets with the benefit of wearables

Movement retraining can correct faulty movement patterns.1 However, as with any treatment, retraining needs to be activity specific—there are various types of ‘retraining’ and the treatment needs to match the movement fault.2 As experts at analysis and rehabilitation of movement, the concept of gait retraining fits well into a sport physiotherapist’s tool kit. The advent of readily accessible high-speed motion capture technology to assess and provide feedback on running patterns allows practitioners to incorporate gait retraining in their clinics. Furthermore, wearable technology makes it possible to measure many metrics ‘in the field’ that were previously only quantifiable in the lab. The purpose of this editorial is to discuss the potential of wearable technology to monitor and give feedback of gait outside of a lab and clinic setting. Traditionally, gait retraining using real-time biofeedback has been conducted in specialised lab settings with variable degrees of success depending on the targeted outcomes and the form of feedback.3 Sport physiotherapists have primarily applied it to treat injured runners, for instance, those with patellofemoral pain.1 4 …

Kinetic risk factors of running-related injuries in female recreational runners

Our objective was to prospectively investigate the association of kinetic variables with running‐related injury (RRI) risk. Seventy‐four healthy female recreational runners ran on an instrumented treadmill while 3D kinetic and kinematic data were collected. Kinetic outcomes were vertical impact transient, average vertical loading rate, instantaneous vertical loading rate, active peak, vertical impulse, and peak braking force (PBF). Participants followed a 15‐week half‐marathon training program. Exposure time (hours of running) was calculated from start of program until onset of injury, loss to follow‐up, or end of program. After converting kinetic variables from continuous to ordinal variables based on tertiles, Cox proportional hazard models with competing risks were fit for each variable independently, before analysis in a forward stepwise multivariable model. Sixty‐five participants were included in the final analysis, with a 33.8% injury rate. PBF was the only kinetic variable that was a significant predictor of RRI. Runners in the highest tertile (PBF < −0.27 BW) were injured at 5.08 times the rate of those in the middle tertile and 7.98 times the rate of those in the lowest tertile. When analyzed in the multivariable model, no kinetic variables made a significant contribution to predicting injury beyond what had already been accounted for by PBF alone. Findings from this study suggest PBF is associated with a significantly higher injury hazard ratio in female recreational runners and should be considered as a target for gait retraining interventions.

Logical fallacies in the running shoe debate: let the evidence guide prescription

For the past 40 years, running shoes have been prescribed on the basis of matching shoe features to foot morphology to prevent running-related injuries (RRI). Yet, traditional shoe prescription has not prevented RRIs—consider five quality randomised controlled trials (RCT) and observational cohort studies.1–5 In contrast, a recent investigation6 found that motion control shoes protected against injury in experienced runners who had pronated feet. There are likely important methodological reasons for the discrepancies between these studies, such as differing definitions of RRI and various experience levels among runners. Nonetheless, there remains a lack of conclusive evidence to support traditional shoe prescription to prevent RRIs.7 Alternative shoe prescription paradigms have emerged. While minimalist shoes have historically received the most attention from researchers, clinicians and runners, the more recent paradigms of maximalism, zero-drop shoes and choosing a shoe based on comfort appear to be gaining in popularity (see figure 1 for examples). Figure 1 Examples of various shoe paradigms. Clockwise from top left: traditional (Brooks Epinephrine 18), minimalist (New Balance Minimus Trail 10), zero-drop (Altra Torin …

Involving clinicians in sports medicine and physiotherapy research: ‘design thinking’ to help bridge gaps between practice and evidence

Bridging the gap between current practice and evidence is not easy in sports medicine. Research findings must be relevant to real-world clinical practice and effectively reach practitioners, who then must understand, interpret and apply them to their patients. Any change in practice requires clinically meaningful research to spark interest among clinicians. The ‘Ikea effect’—where novice builders value their own creations as highly as the work of experts1—provides some insight into a strategy which will help drive clinical research uptake. Specifically, engaging clinicians in the scientific process is key to ensuring effective translation of research to patient care. Sports medicine research needs a ‘design thinking’ approach that prioritises the needs of the end user.2 Design thinking would have clinicians guiding researchers in designing research questions based on experience and interaction with patients to solve practice-generated problems.3 As an example, patients are unlikely to engage in a treatment plan if their beliefs and expectations are not considered in the decision-making process4; increasingly funding organisations require input from patient partners in grant applications. Similarly, clinicians are unlikely to implement, or even read, research that they find irrelevant to their practice, yet it is rare for funding bodies to require clinician partners in grant applications. However, research teams should strongly value input from clinician partners from research conceptualisation …