Blaise Dubois

Is combining gait retraining or an exercise programme with education better than education alone in treating runners with patellofemoral pain?A randomised clinical trial

Design Single-blind randomised clinical trial. Objective To compare the effects of three 8-week rehabilitation programmes on symptoms and functional limitations of runners with patellofemoral pain (PFP). Methods Sixty-nine runners with PFP were randomly assigned to one of three intervention groups: (1) education on symptoms management and training modifications (education); (2) exercise programme in addition to education (exercises); (3) gait retraining in addition to education (gait retraining). Symptoms and functional limitations were assessed at baseline (T0), and after 4, 8 and 20 weeks (T4, T8 and T20) using the Knee Outcome Survey of the Activities of Daily Living Scale (KOS-ADLS) and visual analogue scales (VASs) for usual pain, worst pain and pain during running. Lower limb kinematics and kinetics during running, and isometric strength were also evaluated at T0 and T8. The effects of rehabilitation programmes were assessed using two-way analysis of variance. Results No significant group × time interactions (p<0.447) were found for KOS-ADLS and VASs. All three groups showed similar improvements at T4, T8 and T20 compared with T0 (p<0.05). Only the exercises group increased knee extension strength following rehabilitation (group × time: p<0.001) and only the gait retraining group (group × time: p<0.001) increased step rate (+7.0%) and decreased average vertical loading rate (−25.4%). Conclusion Even though gait retraining and exercises improved their targeted mechanisms, their addition to education did not provide additional benefits on symptoms and functional limitations. Appropriate education on symptoms and management of training loads should be included as a primary component of treatment in runners with PFP. Trial registration number ClinicalTrials.gov (NCT02352909).

Predictors of clinical success in runners with patellofemoral pain: Secondary analyses of a randomized clinical trial

OBJECTIVES To identify predictors of outcome to a rehabilitation program focused on education and management of training loads in runners with patellofemoral pain (PFP). DESIGN Secondary analyses of a randomized clinical trial. METHODS Fifty-eight runners with PFP (62% female, aged 31.2±6.6years, running 20.3±5.6km/week) were included in analyses. Following baseline collection of demographics, anthropometry, symptomatology, isometric strength, running mechanics and radiological data, runners were randomized to one of the three 8-week intervention program: (1) Education on symptoms management and training modifications; (2) Education+Exercise program; (3) Education+Gait retraining. Clinical success was defined as an increase ≥13.6% on the Knee Outcome Survey - Activities of Daily Living Scale (KOS-ADLS) at 3 months following program completion. Potential predictors were entered into logistic regression analyses. RESULTS Forty-five runners (78%) were categorized as Success. Together, KOS-ADLS score (<70%), knee extension isometric strength (<70% bodyweight), presence of patellar tendinopathy (Grade >0) and level of usual pain (>2/10) at baseline predicted treatment outcome with 87.9% accuracy. The model provided sensitivity of 0.93 (95% C.I. 0.82-0.98), specificity of 0.69 (95% C.I. 0.42-0.87), positive likelihood ratio of 3.0 (95% C.I. 1.3-6.9), and negative likelihood ratio of 0.1 (95% C.I. 0-0.3). The best individual predictors were KOS-ADLS score and knee extension strength. CONCLUSIONS The combination of KOS-ADLS, knee extensors strength, patellar tendon integrity and usual pain best predicted clinical outcome of runners with PFP following an intervention that had a common education component. Further testing is needed before a clinical prediction rule can be recommended to clinicians.

Response to: ’Optimising the efficacy of gait retraining'

A recent editorial was published in BJSM 1 following a randomised clinical trial (RCT) conducted by our research team, which compared three rehabilitation programmes in runners with patellofemoral pain (PFP).2 In Dr Davis’ editorial, it was stated that our running intervention was not optimal due to a heterogeneous sample, unstandardised gait modifications and unstructured retraining schedule. While several interesting arguments were presented, readers must keep in mind that the current level of evidence on gait retraining for injured runners is far from conclusive. Previous studies on gait retraining for runners with PFP have addressed specific running mechanics such as rearfoot striking or excessive hip adduction.3 4 However, not all runners with PFP show ‘altered’ mechanics, and PFP is not specific to rearfoot strikers (non-rearfoot strikers also develop PFP). In fact, training errors are thought to contribute to running injuries even in those with ‘optimal’ mechanics.5 Aiming to maximise the external validity of our RCT, we included runners regardless of distal or proximal kinematics, and prescribed individualised …

Footwear characteristics are related to running mechanics in runners with patellofemoral pain

Running footwear is known to influence step rate, foot inclination at foot strike, average vertical loading rate (VLR) and peak patellofemoral joint (PFJ) force. However, the association between the level of minimalism of running shoes and running mechanics, especially with regards to these relevant variables for runners with patellofemoral pain (PFP), has yet to be investigated. The objective of this study was to explore the relationship between the level of minimalism of running shoes and habitual running kinematics and kinetics in runners with PFP. Running shoes of 69 runners with PFP (46 females, 23 males, 30.7±6.4years) were evaluated using the Minimalist Index (MI). Kinematic and kinetic data were collected during running on an instrumented treadmill. Principal component and correlation analyses were performed between the MI and its subscales and step rate, foot inclination at foot strike, average VLR, peak PFJ force and peak Achilles tendon force. Higher MI scores were moderately correlated with lower foot inclination (r=-0.410, P<0.001) and lower peak PFJ force (r=-0.412, P<0.001). Moderate correlations also showed that lower shoe mass is indicative of greater step rate (ρ=0.531, P<0.001) and lower peak PFJ force (ρ=-0.481, P<0.001). Greater shoe flexibility was moderately associated with lower foot inclination (ρ=-0.447, P<0.001). Results suggest that greater levels of minimalism are associated with lower inclination angle and lower peak PFJ force in runners with PFP. Thus, this population may potentially benefit from changes in running mechanics associated with the use of shoes with a higher level of minimalism.

Effects of minimalist and traditional running shoes on injury rates: a pilot randomised controlled trial

Despite recent advances in running shoe conception, injuries represent a major concern in the running community. The objective of this study was to gather the pilot data for a larger randomised controlled trial regarding the effects of traditional and minimalist shoes on the incidence of running-related injuries (RRI), as well as the rate of adherence to a running programme. Twenty-six recreational runners were recruited. They were randomly assigned to minimalist (MS) or traditional (TS) shoes and participated in a 16-week training programme. The information on previously reported risk factors for RRI was gathered. Participants reported pain and compliance using an online tool. Main outcome measures included the rates of recruitment, adherence to the programme and programme completion, RRI and the missed training days secondary to the running-related pain. The recruited runners represented 72.2% of potential participants, among which 20 (76.9%) completed the programme. Two subjects dropped out before randomisation, plus three in MS and one in TS during the programme. Rate of adherence was 82.4% in MS and 86.2% in TS. Three runners per group sustained an RRI (25%, 95% C.I. = 9.8%–46.7%). Results support the feasibility of a larger scale study. A total of 116 runners would be needed to detect a clinically significant difference of 20% in injury incidence between MS and TS.