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

Transfer Learning Effects of Biofeedback Running Retraining in Untrained Conditions

PURPOSE

Running gait retraining via peak tibial shock biofeedback has been previously shown to reduce impact loading and mitigate running-related symptoms. In previous research, peak tibial shock is typically measured and trained for one limb at a single constant training speed during all training sessions. The goal of this study was to determine how runners transfer learning in the trained limb to the untrained limb at different unconstrained speeds.

METHODS

Thirteen runners (3 females, age = 41.1 ± 6.9 yr, running experience = 6.8 ± 4.4 yr, weekly running distance = 30.7 ± 22.2 km) underwent running gait biofeedback retraining via continuous tibial acceleration measured at the right distal tibia. Before and after the training, participants were asked to run at their self-selected constrained training speeds (2.8 ± 0.2 m·s) and at 110% and 90% of the training speed. Pretraining and posttraining peak tibial shock values for each limb were compared.

RESULTS

Participants reduced peak tibial shock in the trained limb by 35% to 37% (P < 0.05, Cohen's d = 0.78-0.85), and in the untrained limb by 20% to 23% (P < 0.05, Cohen's d = 0.51-0.71) across the three testing speeds. The reduction was not significantly different between the trained and untrained limbs (P = 0.31-0.79, Cohen's d = 0.18-0.45). Similarly, there was no difference in peak tibial shock reduction among the three running speeds (P = 0.48-0.61, Cohen's d = 0.06-0.45).

CONCLUSION

Participants demonstrated transfer learning effects evidenced by concomitant reduced peak tibial shock in the untrained limb, and the learning effects were retrained when running at a 10% variance of the training speed.

Real-Time Biofeedback of Performance to Reduce Braking Forces Associated With Running-Related Injury: An Exploratory Study

BACKGROUND

The high rate of running-related injury may be associated with increased peak braking forces (PBFs) and vertical loading rates. Gait retraining has been suggested by some experts to be an effective method to reduce loading parameters.

OBJECTIVES

To investigate whether PBF could be decreased following an 8-session gait retraining program among a group of female recreational runners and which self-selected kinematic strategies could achieve this decrease.

METHODS

In this exploratory study, 12 female recreational runners with high PBFs (greater than 0.27 body weight) completed an 8-session gait retraining program with real-time biofeedback of braking forces over the course of a half-marathon training program. Baseline and follow-up kinetics and kinematics were analyzed with a repeated-measures analysis of variance.

RESULTS

There was an average reduction of 15% in PBF (-0.04 body weight; 95% confidence interval [CI]: -0.07, -0.02 body weight; P = .001; effect size, 0.62), accompanied by a 7% increase in step frequency (11.3 steps per minute; 95% CI: 1.8, 20.9 steps per minute; P = .024; effect size, 0.38) and a 6% decrease in step length (-5.5 cm; 95% CI: -9.9, -1.0 cm; P = .020; effect size, 0.40), from baseline to follow-up.

CONCLUSION

The gait retraining program significantly reduced the PBF among a group of female recreational runners. This was achieved through a combination of increased step frequency and decreased step length. Furthermore, the modified gait pattern was incorporated into the runners' natural gait pattern by the completion of the program. Based on these results, the outlined gait retraining program should be further investigated to assess whether it may be an effective injury prevention strategy for recreational runners. This study was registered with ClinicalTrials.gov (NCT03302975).

LEVEL OF EVIDENCE

Prevention, level 4. J Orthop Sports Phys Ther 2019;49(3):136-144. Epub 7 Dec 2018. doi:10.2519/jospt.2019.8587.

The effect of an individualised functional retraining intervention on pain, function and biomechanics in participants with patellofemoral pain: a series of n of 1 trial

[Purpose] To determine the effect of an individualised functional retraining intervention on pain, function, kinematics and self-reported recovery in participants with PFP. [Participants and Methods] Thirty-one participants with unilateral PFP between the ages of 14–40 were included. Data collection and treatment sessions were conducted at the Tygerberg 3D Motion Analysis Laboratory and Physiotherapy Clinic at the University of Stellenbosch Medical School in Cape Town, South Africa. Participants underwent motion analysis testing pre- and post-intervention and attended physiotherapy weekly for a 6-week individualised intervention. [Results] Thirty of the thirty-one participants (96.8%) demonstrated improved pain levels (NPRS) post intervention. Participants demonstrated a statistically significant improvement in function (AKPS) immediately post intervention and continued to improve with greater functional scores at 6-month follow up. Fifteen participants (48.4%) rated themselves as fully recovered on a 7-point Likert scale at 6-month follow up. Nineteen of the 31 participants (61.3%) demonstrated a clinically significant improvement in their priority kinematic outcome post intervention. [Conclusion] Individualised functional retraining may improve pain, function, kinematics and long-term recovery in participants with PFP presenting with kinematic contributing factors. Clinicians need to be educated on common biomechanical contributing factors and how to tailor treatment accordingly.

Progression in Running Intensity or Running Volume and the Development of Specific Injuries in Recreational Runners: Run Clever, a Randomized Trial Using Competing Risks

BACKGROUND

It has been proposed that training intensity and training volume are associated with specific running-related injuries. If such an association exists, secondary preventive measures could be initiated by clinicians, based on symptoms of a specific injury diagnosis.

OBJECTIVES

To test the following hypotheses: (1) a running schedule focusing on running intensity (S-I) would increase the risk of sustaining Achilles tendinopathy, gastrocnemius injuries, and plantar fasciitis compared with hypothesized volume-related injuries; and (2) a running schedule focusing on running volume (S-V) would increase the risk of sustaining patellofemoral pain syndrome, iliotibial band syndrome, and patellar tendinopathy compared with hypothesized intensity-related injuries.

METHODS

In this randomized clinical trial and etiology study, healthy recreational runners were included in a 24-week follow-up, divided into 8-week preconditioning and 16-week specific-focus training periods. Participants were randomized to 1 of 2 running schedules: S-I or S-V. The S-I group progressed the amount of high-intensity running (88% maximal oxygen consumption [VO₂max] or greater) each week, and the S-V group progressed total weekly running volume. A global positioning system watch or smartphone collected data on running. Running-related injuries were diagnosed based on a clinical examination. Estimates were reported as risk difference and 95% confidence interval (CI).

RESULTS

Of 447 runners, a total of 80 sustained an injury (S-I, n = 36; S-V, n = 44). Risk differences (95% CIs) of intensity injuries in the S-I group were -0.8% (-5.0%, 3.4%) at 2 weeks, -0.8% (-6.7%, 5.1%) at 4 weeks, -2.0% (-9.2%, 5.2%) at 8 weeks, and -5.1% (-16.5%, 6.3%) at 16 weeks. Risk differences (95% CIs) of volume injuries in the S-V group were -0.9% (-5.0%, 3.2%) at 2 weeks, -2.0% (-7.5%, 3.5%) at 4 weeks, -3.2% (-9.1%, 2.7%) at 8 weeks, and -3.4% (13.2%, 6.2%) at 16 weeks.

CONCLUSION

No difference in risk of hypothesized intensity- and volume-specific running-related injuries exists between the 2 running schedules focused on progression in either running intensity or volume.

LEVEL OF EVIDENCE

Etiology, level 1b. J Orthop Sports Phys Ther 2018;48(10):740-748. Epub 12 Jun 2018. doi:10.2519/jospt.2018.8062.

Differences in pain and function between adolescent athletes and physically active non-athletes with patellofemoral pain

OBJECTIVES

To investigate pain level and function limitation in adolescent athletes and physically active non-athletes with PFP.

DESIGN

Cross-sectional study.

SETTING

Adolescent athletes were recruited at a sport center complex. Adolescent non-athletes were recruited from upper secondary schools.

PARTICIPANTS

108 adolescents diagnosed with PFP: 42 adolescent athletes and 66 adolescent non-athletes.

MAIN OUTCOME MEASURES

To evaluate the level of pain, a visual analog scale (VAS) was used and to evaluate the overall function, the Knee Outcome in Osteoarthritis Survey (KOOS) was used.

RESULTS

The adolescent athletes scored significantly higher in the VAS (Mean difference = 0.97 (95% CI = 0.35; 1.60) p = 0.003) compared to adolescent non-athletes. Adolescent athletes scored lower in the KOOS - Symptoms, Pain, Knee-related quality of life and Sport and recreation dimensions - than the non-athletes, however, the minimally clinically important difference was not achieved in Pain dimension. There was no significant difference in the Activities of daily living dimension of the KOOS.

CONCLUSIONS

Adolescent athletes presented higher levels of pain and lower physical function status compared with physically active non-athletes. This provides an important insight to the management of PFP in adolescent athletes as worst functional status is linked with poor prognosis in patients with PFP.

2018 Consensus statement on exercise therapy and physical interventions (orthoses, taping and manual therapy) to treat patellofemoral pain: recommendations from the 5th International Patellofemoral Pain Research Retreat, Gold Coast, Australia, 2017

Patellofemoral pain affects a large proportion of the population, from adolescents to older adults, and carries a substantial personal and societal burden. An international group of scientists and clinicians meets biennially at the International Patellofemoral Research Retreat to share research findings related to patellofemoral pain conditions and develop consensus statements using best practice methods. This consensus statement, from the 5th International Patellofemoral Research Retreat held in Australia in July 2017, focuses on exercise therapy and physical interventions (eg, orthoses, taping and manual therapy) for patellofemoral pain. Literature searches were conducted to identify new systematic reviews and randomised controlled trials (RCTs) published since the 2016 Consensus Statement. The methodological quality of included systematic reviews and RCTs was graded using AMSTAR and PEDro, respectively. Evidence-based statements were developed from included papers and presented to a panel of 41 patellofemoral pain experts for consensus discussion and voting. Recommendations from the expert panel support the use of exercise therapy (especially the combination of hip-focused and knee-focused exercises), combined interventions and foot orthoses to improve pain and/or function in people with patellofemoral pain. The use of patellofemoral, knee or lumbar mobilisations in isolation, or electrophysical agents, is not recommended. There is uncertainty regarding the use of patellar taping/bracing, acupuncture/dry needling, manual soft tissue techniques, blood flow restriction training and gait retraining in patients with patellofemoral pain. In 2017, we launched the International Patellofemoral Research Network (www.ipfrn.org) to consolidate and grow our patellofemoral research community, facilitate collaboration and disseminate patellofemoral pain knowledge to clinicians and the general public. The 6th International Patellofemoral Research Retreat will be held in Milwaukee, Wisconsin, USA, in October 2019.

The effects & mechanisms of increasing running step rate: A feasibility study in a mixed-sex group of runners with patellofemoral pain

OBJECTIVES

To explore feasibility of recruitment and retention of runners with patellofemoral pain (PFP), before delivering a step rate intervention.

DESIGN

Feasibility study.

SETTING

Human performance laboratory.

PARTICIPANTS

A mixed-sex sample of runners with PFP (n = 11).

MAIN OUTCOME MEASURES

Average/worst pain and the Kujala Scale were recorded pre/post intervention, alongside lower limb kinematics and surface electromyography (sEMG), sampled during a 3 KM treadmill run.

RESULTS

Recruitment and retention of a mixed-sex cohort was successful, losing one participant to public healthcare and with kinematic and sEMG data lost from single participants only. Clinically meaningful reductions in average (MD = 2.1, d = 1.7) and worst pain (MD = 3.9, d = 2.0) were observed. Reductions in both peak knee flexion (MD = 3.7°, d = 0.78) and peak hip internal rotation (MD = 5.1°, d = 0.96) were observed, which may provide some mechanistic explanation for the identified effects. An increase in both mean amplitude (d = 0.53) and integral (d = 0.58) were observed for the Vastus Medialis Obliqus (VMO) muscle only, of questionable clinical relevance.

CONCLUSIONS

Recruitment and retention of a mixed sex PFP cohort to a step rate intervention involving detailed biomechanical measures is feasible. There are indications of both likely efficacy and associated mechanisms. Future studies comparing the efficacy of different running retraining approaches are warranted.

How to manage patellofemoral pain - Understanding the multifactorial nature and treatment options

Patellofemoral pain (PFP) is one of the most prevalent conditions within sports medicine, orthopaedic and general practice settings. Long-term treatment outcomes are poor, with estimates that more than 50% of people with the condition will report symptoms beyond 5 years following diagnosis. Additionally, emerging evidence indicates that PFP may be on a continuum with patellofemoral osteoarthritis. Consensus of world leading clinicians and academics highlights the potential benefit of delivering tailored interventions, specific to an individual's needs, to improve patient outcome. This clinical masterclass aims to develop the reader's understanding of PFP aetiology, inform clinical assessment and increase knowledge regarding individually tailored treatment approaches. It offers practical application guidance, and additional resources, that can positively impact clinical practice.

Do hip muscle weakness and dynamic knee valgus matter for the clinical evaluation and decision-making process in patients with patellofemoral pain?

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Hip muscle weakness in PFP patients may be consequence and not the cause of pain.

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Pain and disability may not be associated with kinematics after treatment.

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Hip muscle weakness may have no causal relationship with dynamic knee valgus.

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The mechanical factors that may impair the management of PFP are likely to be overestimated.

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PFP patients should be treated on a biopsychosocial approach.

Background

Patellofemoral pain is a very common musculoskeletal condition. In the last years, evidence regarding this disease increased exponentially. Although widely investigated, this problem still frustrates patients and clinicians for having an unfavorable prognosis. Some gaps still exist in the understanding and managing of patellofemoral pain. Numerous cross-sectional association studies show an association between gluteus muscular strength and dynamic knee valgus in patients with patellofemoral pain. In spite of this biological plausibility, many evidences challenge the direct relationship between these factors. Recent studies have concluded that women with patellofemoral pain show muscular weakness of the hip based on the cross-sectional studies, however prospective studies indicate that hip weakness cannot be considered a risk for development of patellofemoral pain. In addition, some clinical trials have demonstrated that strength training of the gluteal muscles promotes significant improvement in symptoms but not alter the kinematics of the patients with patellofemoral pain. These findings cast doubt on whether the cause of this condition is really being treated, whether all individuals suffering from patellofemoral pain present dynamic knee valgus or if this is a disturbance present in only a subgroup of patients and whether the strengthening of the hip musculature is an option to consider for prevention of patellofemoral pain.

Conclusion

Certainly, more studies should be conducted to clarify the influence of mechanical patterns on this condition, but with the existing evidence so far, the importance given to these issues in the evaluation and clinical decision on treatment of these patients seems questionable. Therefore, this masterclass explores the understanding about patellofemoral pain, highlighting mainly the importance of muscular strength and dynamic knee valgus, as well as other possible factors that must be consider during the evaluation and the decision making in these patients.