Effects of rehabilitation approaches for runners with patellofemoral pain: protocol of a randomised clinical trial addressing specific underlying mechanisms

Evidence based treatment options for common knee injuries in runners

The purpose of this paper is to review the current literature regarding conservative treatment options for the three most common knee injuries in runners including patellofemoral pain syndrome (PFPS), iliotibial band friction syndrome (ITBFS), and patellar tendinopathy (PT). Each diagnosis is discussed using current research to describe the pathophysiology, evaluation process, and evidence based effective treatment strategies including therapeutic exercise, manual therapy, neuromuscular re-education, and modalities. The result is a comprehensive overview of each diagnosis and a research-based approach to effectively evaluate and treat each condition for best outcomes.

Patellofemoral Pain

Patellofemoral pain (PFP) is a common musculoskeletal-related condition that is characterized by insidious onset of poorly defined pain, localized to the anterior retropatellar and/or peripatellar region of the knee. The onset of symptoms can be slow or acutely develop with a worsening of pain accompanying lower-limb loading activities (eg, squatting, prolonged sitting, ascending/descending stairs, jumping, or running). Symptoms can restrict participation in physical activity, sports, and work, as well as recur and persist for years. This clinical practice guideline will allow physical therapists and other rehabilitation specialists to stay up to date with evolving PFP knowledge and practices, and help them to make evidence-based treatment decisions. J Orthop Sports Phys Ther. 2019;49(9):CPG1-CPG95. doi:10.2519/jospt.2019.0302.

Effect of experimental muscle pain on the acquisition and retention of locomotor adaptation: different motor strategies for a similar performance

As individuals with musculoskeletal disorders often experience motor impairments, contemporary rehabilitation relies heavily on the use of motor learning principles. However, motor impairments are often associated with pain. Although there is substantial evidence that muscle pain interferes with motor control, much less is known on its impact on motor learning. The objective of the present study was to assess the effects of muscle pain on locomotor learning. Two groups (Pain and Control) of healthy participants performed a locomotor adaptation task (robotized ankle-foot orthosis perturbing ankle movements during swing) on two consecutive days. On day 1 (acquisition), hypertonic saline was injected in the tibialis anterior (TA) muscle of the Pain group participants, while Control group participants were pain free. All participants were pain free on day 2 (retention). Changes in movement errors caused by the perturbation were assessed as an indicator of motor performance. Detailed analysis of kinematic and electromyographic data provided information about motor strategies. No between-group differences were observed on motor performance measured during the acquisition and retention phases. However, Pain group participants had a residual movement error later in the swing phase and smaller early TA activation than Control group participants, thereby suggesting a reduction in the use of anticipatory motor strategies to overcome the perturbation. Muscle pain did not interfere with global motor performance during locomotor adaptation. The different motor strategies used in the presence of muscle pain may reflect a diminished ability to anticipate the consequences of a perturbation. NEW & NOTEWORTHY This study shows that experimental muscle pain does not influence global motor performance during the acquisition or next-day retention phases of locomotor learning. This contrasts with previous results obtained with cutaneous pain, emphasizing the risk of directly extrapolating from one pain modality to another. Muscle pain affected motor strategies used when performing the task, however: it reduced the ability to use increased feedforward control to overcome the force field.

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.

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).