Dose–response effects of medical exercise therapy in patients with patellofemoral pain syndrome: a randomised controlled clinical trial

doi:10.1016/j.physio.2012.05.009

Physiotherapy

Volume 99, Issue 2, June 2013, Pages 126-131

https://doi.org/10.1016/j.physio.2012.05.009 Get rights and content

Abstract

Participants

Forty-two patients with PFPS were assigned at random to an experimental group or a control group. Forty participants completed the study.

Interventions

Both groups received three treatments per week for 12 weeks. The experimental group received high-dose, high-repetition medical exercise therapy, and the control group received low-dose, low-repetition exercise therapy. The groups differed in terms of number of exercises, number of repetitions and sets, and time spent performing aerobic/global exercises.

Main outcome measures

Outcome parameters were pain (measured using a visual analogue scale) and function [measured using the step-down test and the modified Functional Index Questionnaire (FIQ)].

Results

At baseline, there were no differences between the groups. After the interventions, there were statistically significant (P < 0.05) and clinically important differences between the groups for all outcome parameters, all in favour of the experimental group: −1.6 for mean pain [95% confidence interval (CI) −2.4 to −0.8], 6.5 for step-down test (95% CI 3.8 to 9.2) and 3.1 for FIQ (95% CI 1.2 to 5.0).

Conclusion

The results indicate that exercise therapy has a dose–response effect on pain and functional outcomes in patients with PFPS. This indicates that high-dose, high-repetition medical exercise therapy is more efficacious than low-dose, low-repetition exercise therapy for this patient group.

Registered on http://www.clinicaltrials.gov (identifier: NCT01290705).

Introduction

Patellofemoral pain is characterised by anterior or retropatellar pain associated with activities that load the patellofemoral joint, such as ascending or descending stairs, squatting, running and kneeling. Patellofemoral pain syndrome (PFPS) is the most common complaint affecting the knee [1]. In sports medicine practices, PFPS is reported to represent up to 25% of all new running injuries [2]. Women are more likely to be affected than men [3].

The main symptom of PFPS is pain, and the condition generally progresses to impaired function. Based on underlying theoretical constructs and previous research, several factors or impairments such as muscle weakness [4], soft tissue tightness [5], structural and biomechanical alterations of the lower extremities [6], quality of movement [7] and psychological factors [8], [9] have been suggested to contribute to the occurrence of PFPS. There is no agreement on the aetiology of PFPS or the most appropriate treatment, but there is general consensus that the preferred treatment approach is non-surgical [10].

For many years, the non-surgical treatment approach has been to address the assumed abnormal tracking and/or malalignment in patients with PFPS [1], and this method typically includes quadriceps strengthening [2], [11], [12], patellar bracing and taping [13], [14], soft tissue mobilisation and stretching [15]. Unfortunately, the results of such treatment approaches have been mixed [2], [13]. A review of exercise therapy for PFPS concluded that there is limited evidence for the efficacy of exercise in treating pain, and conflicting evidence for functional outcome [16]. It is reported that approximately 25% of patients continue to have pain and dysfunction 1 year or more after physiotherapy, but physiotherapy is still the most commonly used conservative treatment for PFPS [8].

The effects of different treatment doses using exercise therapy in patients with PFPS have not been examined. Studies in patients with longstanding subacromial pain have reported a dose–response effect of exercise therapy, with high-dose, high-repetition medical exercise therapy (MET) found to be the most efficient approach [17], [18]. The mechanisms behind the clinical effects are still unclear, although tendon regeneration has been demonstrated [19], possibly due to increased circulation and intermittent tension release mechanisms [20]. Perceived pain reduction and improvements in function are also thought to pursue central pain modulation induced by considerable amounts of aerobic exercise [21].

The purpose of this trial was to study the dose–response effects of graded exercise therapy on pain and functional outcomes in patients with PFPS, comparing two different therapeutic exercise regimens.

Section snippets

Study design

This was a multicentre, randomised controlled clinical trial. The study protocol was approved by the Regional Ethics Committee, and is registered on http://www.clinicaltrials.gov (identifier: NCT01290705). Eligible patients were given written information about the study before giving their written consent to participate.

Patient selection

Participants were recruited by general practitioners and orthopaedists referring patients with PFPS to the three physiotherapy clinics involved in this study. The inclusion

Results

In total, 42 patients with PFPS were included in this study (21 in each group). Due to two dropouts in the control group, 19 patients in the control group and 21 patients in the experimental group were analysed (Fig. B, see supplementary online material). As the two dropouts did not influence the group sizes significantly, it was considered convenient to include the actual population in the analyses (i.e. the participants actually completing the interventions). The sample size still remained

Discussion

This study found high-dose, high-repetition MET to be an efficacious treatment approach in patients with PFPS. For all outcome parameters, the results for the experimental group were significantly better than those for the control group after 12 weeks of rehabilitation.

Conclusion

This randomised controlled clinical trial compared two different therapeutic exercise regimens in patients with PFPS, based on either high-dose, high-repetition MET (experimental group) or low-dose, low-repetition exercise therapy (control group). There were significant differences between the two groups after the 12-week interventions. The results indicate possible dose–response effects of exercise in this patient population in terms of pain and functional outcomes, indicating that high-dose,

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Effects of high frequency strengthening on pain sensitivity and function in female runners with chronic patellofemoral pain
2024, Physical Therapy in Sport
To investigate the effects of a high frequency strengthening program on function, pain, and pain sensitization in female runners with chronic patellofemoral pain (PFP).
Cross-sectional study.
University laboratory.
Thirty female runners (mean age 32 ± 8.1 years) with chronic PFP completed an 8-week home strengthening program.
Variables assessed at baseline, 8-weeks, and 12 weeks included single leg step down test (SLSD), pain, Anterior Knee Pain Scale (AKPS), University of Wisconsin Running Injury and Recovery Index (UWRI), and quantitative sensory testing.
There was large and statistically significant improvement at 8 and 12 weeks for average knee pain (η_p² = 0.334, p < 0.001), worst knee pain (η_p² = 0.351, p < 0.001), SLSD (η_p² = 0.161, p = 0.001), AKPS (η_p² = 0.463, p < 0.001), and UWRI (η_p² = 0.366, p < 0.001). A medium to large effect and statistically significant improvement in pressure pain threshold testing was found for all local and remote structures (η_p² range, 0.110 to 0.293, range p < 0.001 to p = 0.009) at 8 and 12 weeks.
There was a significant decrease in local and remote hyperalgesia via mechanical and thermal pain sensitivity testing in female runners with chronic PFP. There was a large effect and significant improvement in self-reported pain and function.
Dose-response effect of lower limb resistance training volume on pain and function of women with patellofemoral pain: A systematic review and meta-regression
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Analyze whether the effects of lower limb resistance training on pain and self-reported function were associated with the exercise volume prescribed for women with patellofemoral pain (PFP).
A systematic search was undertaken in four databases from inception to May 2023. Eligible trials examined the effects of resistance training programs on pain (visual analogue scale or numerical pain scale) and function (Anterior Knee Pain Scale) in women with PFP. Meta-analysis was undertaken with a random-effects model. The association of resistance training volume-related variables with mean difference effects on pain and function were tested by exploratory univariable meta-regression models.
From 1,404 estudies retained for screening after duplicate removals, 16 studies (579 patients) were included. Changes in knee pain were inversely associated with weekly training frequency (β = 0.5 ± 0.2, P = 0.012). No associations were found between the amount of resistance exercise prescribed per session or per week and effects on pain. Changes in function were associated with the number of sets per week (β = 0.1 ± 0.1, P = 0.044) and number of sets per session (β = 0.6 ± 0.2, P < 0.001) over the intervention. Most favorable results were achieved with 17 to 27 sets per session and >45 sets per week.
The amount of prescribed resistance exercise does not seem to be critical for pain reduction in women with PFP. However, our findings support a dose-response effect in terms of improving function.
Patient experience of the diagnosis and management of patellofemoral pain: A qualitative exploration
2022, Musculoskeletal Science and Practice
Citation Excerpt :
Exercise therapy, the primary intervention advocated by the most recent PFP consensus statement (Collins et al., 2018; van der Heijden et al., 2015), was the dominant treatment that participants experienced, but with variable prescription and outcomes. Participants that received tailored exercises, with regular support and adjustments from their physiotherapist (Lack et al., 2015; Østerås et al., 2013), did return to activities such as running. However, most participants did not report receiving a tailored exercise programme or an improvement in pain.
Patellofemoral pain (PFP) is common and long-term treatment outcomes are unsatisfactory. Qualitative exploration of diagnosis and management from the perspective of people with PFP is lacking.
To inform care and improve intervention delivery by exploring the experience of people with PFP regarding diagnosis and management.
Qualitative study with semi-structured interviews.
Online recruiting yielded a convenience sample of participants with PFP for semi-structured interview. Interviews were recorded, transcribed verbatim, and analysed using thematic analysis until theoretical saturation by multiple investigators to determine themes and sub-themes.
12 participants were interviewed, with three themes identified; the value of diagnosis, the need for tailored (individualised) care, and the role of education. Participants viewed receiving a diagnosis as essential to guide management, yet one was rarely provided, causing uncertainty about pain mechanisms; “it's nice to be told what it is that's wrong”. Interventions needed to be tailored to the individual as not all participants responded in the same way to treatment(s) or had the same needs; “everyone copes and reacts differently”. Finally, participants viewed education as essential to empower them to understand and manage the condition; “if I'd have been given more information, I think I'd know how to deal with it more”.
The overarching narrative from three themes was a desire for clearly communicated personalised care that meets individual needs. People with PFP desire a diagnosis to explain their pain, tailored interventions, and appropriate education to optimise their experience and outcomes.
Nonoperative Care Including Rehabilitation Should Be Considered and Clearly Defined Prior to Elective Orthopaedic Surgery to Maximize Optimal Outcomes
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Orthopaedic surgery has revolutionized the expectations for restoration of physical function after musculoskeletal injury and, along with physical therapy, has transformed the limits of recovery. Many orthopaedic procedures have a high success rate for improving quality of life and patient-reported outcomes, yet these procedures carry some level of risk, including postoperative complications. The stepped-care model of health care delivery, when applied to musculoskeletal care, recommends implementing less-intense and lower-risk treatments with known efficacy, such as promotion and education of self-management strategies and physical therapy, before more-invasive and higher-risk treatments such as surgery. This model of managing musculoskeletal disability can improve efficiency of care delivery and reduce medical costs at the health system level. Unfortunately, there is a documented lack of implementing an appropriate course of conservative care, especially physical therapy, prior to surgery across multiple orthopaedic disciplines including sports, spine, and trauma medicine and joint arthroplasty. Failure to respond to nonsurgical treatment has been suggested as a requisite component of the surgical appropriateness criteria, yet practical application can be elusive. Multiple barriers to adequate utilization of conservative treatment exist, including U.S. payment models that increase out-of-pocket expense for patients, negative patient perception of therapy, unreasonable patient expectations from therapy versus surgery, and communication barriers between patient, surgeon, and therapist. Surgeons should ensure that high-quality guideline-appropriate care is delivered early and adequately to their patients. Rehabilitation professionals have a responsibility to deliver high-value care, properly documenting the type and extent of treatment to improve surgical decision-making between surgeons and patients. Criteria to determine appropriateness for surgery should include a standardized and extensive assessment of failed therapies prior to certain elective surgeries. Improved collaboration between surgeons and rehabilitation professionals can result in improved outcomes for patients with musculoskeletal disorders.
V, expert opinion
Self-dosed and pre-determined progressive heavy-slow resistance training have similar effects in people with plantar fasciopathy: a randomised trial
2019, Journal of Physiotherapy
Citation Excerpt :
The experimental and control programs appear to be two different ways of achieving the same exercise dose and clinical results. Although previous studies have indicated an association between exercise dose and recovery,50,51 this association was not observed in the present trial; however, it should be noted that the analyses of correlations may not have been reliable due to the present trial’s sample size. The results of the present trial raise the question of whether there is a role for heavy-slow resistance training in plantar fasciopathy management.
For people with plantar fasciopathy, is a 12-week self-dosed heavy-slow resistance training program more beneficial than a 12-week pre-determined heavy-slow resistance training program?
A randomised trial with concealed allocation, partial blinding, and intention-to-treat analysis.
Seventy people with plantar fasciopathy confirmed on ultrasonography.
Both groups performed a repeated heel raise exercise in standing for 12 weeks. Participants in the experimental group were self-dosed (ie, they performed as many sets as possible with as heavy a load as possible, but no heavier than 8 repetition maximum). The exercise regimen for the control group was pre-determined (ie, it followed a standardised progressive protocol).
The primary outcome was the Foot Health Status Questionnaire pain domain. Secondary outcomes included: a 7-point Likert scale of Global Rating of Change dichotomised to ‘improved’ or ‘not improved’; Patient Acceptable Symptom State defined as when participants felt no further need for treatment; and number of training sessions performed.
There was no significant between-group difference in the improvement of Foot Health Status Questionnaire pain after 12 weeks (adjusted MD −6.9 points, 95% CI −15.5 to 1.7). According to the Global Rating of Change, 24 of 33 in the experimental group and 20 of 32 in the control group were improved (RR = 1.16, 95% CI 0.83 to 1.64). Only four participants achieved Patient Acceptable Symptom State: three of 35 in the experimental group and one of 35 in the control group. No significant between-group difference was found in the number of training sessions that were performed (MD −2 sessions, 95% CI −8 to 3).
Self-dosed and pre-determined heavy-slow resistance exercise programs are associated with similar effects on plantar fasciopathy pain and other outcomes over 12 weeks. Advising people with plantar fasciopathy to self-dose their slow-heavy resistance training regimen did not substantially increase the achieved dose compared with a pre-determined regimen. These regimens are not sufficient to achieve acceptable symptom state in the majority of people with plantar fasciopathy.
ClinicalTrials.gov NCT03304353.
Effects of Core Neuromuscular Training on Pain, Balance, and Functional Performance in Women With Patellofemoral Pain Syndrome: A Clinical Trial
2019, Journal of Chiropractic Medicine
Citation Excerpt :
This test was repeated 3×, and the average of the 3 numbers was recorded as the final score. The height of the step was 20 cm.34 This test simulates stair descent and is correlated with pain in patients with PFPS and has high intrarater reliability (0.94).35
The purpose of this study was to determine the effects of core neuromuscular training on pain, balance, and performance in women with patellofemoral pain syndrome (PFPS).
This randomized single-blind trial was based on a convenience sample of 28 women with unilateral PFPS. All participants were assigned randomly to the intervention or control group with a block randomization method. The control group received routine physical therapy exercise for PFPS. The intervention group received core neuromuscular training in addition to routine physical therapy exercise. The outcome measures evaluated were pain intensity (Visual Analog Scale), function (Kujala patellofemoral questionnaire and step-down performance test), and balance (Y balance test).
In both groups the pain score was significantly lower after treatment (P = .001). The slope of this trend was greater in the intervention group. The Kujala and step-down scores improved significantly after treatment in both groups, although the improvements were greater in the intervention group. The Y balance score improved in all 3 directions after therapy in both groups (P < .05); improvement was significantly greater in the intervention group only in the posteromedial direction (P = .016).
For the group of participants studied, a 4-week core neuromuscular training plus routine physiotherapy exercise was more effective than routine physiotherapy exercise alone for improving pain, balance, and functional performance in individuals with PFPS.

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Dose–response effects of medical exercise therapy in patients with patellofemoral pain syndrome: a randomised controlled clinical trial

Abstract

Objectives

Design

Setting

Participants

Interventions

Main outcome measures

Results

Conclusion

Introduction

Section snippets

Study design

Patient selection

Results

Discussion

Conclusion

Arch Phys Med Rehabil

Arch Phys Med Rehabil

Pain

Man Ther

Arch Phys Med Rehabil

Eur J Pain

The measurement of patellar alignment in patellofemoral pain syndrome: are we confusing assumptions with evidence?

J Orthop Sports Phys Ther

Supervised exercise therapy versus usual care for patellofemoral pain syndrome: an open label randomised controlled trial

BMJ

Gender differences in the incidence and prevalence of patellofemoral pain syndrome

Scand J Med Sci Sports

Delayed vastus medialis obliquus to vastuslateralis onset timing contributes to the development of patellofemoral pain in previously healthy men: a prospective study

Am J Sports Med

Adolescent patellofemoral pain: implicating the medial patellofemoral ligament as the main pain generator

J Child Orthop

Q-angle and J-sign: indicative of maltracking subgroups in patellofemoral pain

Clin Orthop Relat Res

Do females with patellofemoral pain have abnormal hip and knee kinematics during gait?

Physiother Theory Pract

Associates of physical function and pain in patients with patellofemoral pain syndrome

Arch Phys Med Rehabil

Predictors of pain and function outcome after rehabilitation in patients with patellofemoral pain syndrome

J Rehabil Med

Clinical classification of patellofemoral pain syndrome: guidelines for non-operative treatment

Knee Surg Sports Traumatol Arthrosc

Open versus closed kinetic chain exercises for patellofemoral pain. A prospective, randomized study

Am J Sports Med

Physiotherapy for anterior knee pain: a randomised controlled trial

Ann Rheum Dis