Lack S, Barton C, Sohan O, Crossley K, Morrissey D. Proximal muscle rehabilitation is effective for patellofemoral pain: a systematic review with meta-analysis. Br J Sports Med. 2015;49:1365–1376.
Clinical Question: Is proximal musculature rehabilitation efficient in improving outcomes for patients with patellofemoral pain?
Data Sources: Randomized controlled trials and cohort studies including information on proximal rehabilitation for patellofemoral pain were identified using Web of Knowledge, CINAHL, EMBASE, and Medline databases. Search terms included patellofemoral OR anterior knee pain, AND proximal OR gluteal, AND strength, AND training OR program OR exercise OR rehab. Participants who described having patellofemoral pain, anterior knee pain, or chondromalacia patella without the presence of another knee injury were included. Additionally, participants had to complete a rehabilitation protocol that included exercises directed at the hip or lumbopelvic musculature or both muscle groups.
Study Selection: Fourteen studies were included in the review and seven were considered high quality.
Data Extraction: Two reviewers assessed each article, and a third reviewer was available for inclusion and quality consensus through the PEDro scale and the PFP inclusion/ exclusion criteria checklist. Means and standard deviations for all data were extracted and entered into the Cochrane Review Manager.
Main Results: There is strong evidence to support the use of proximal muscle rehabilitation combined with quadriceps rehabilitation to decrease pain and improve function in the short term (< 3 months) and medium term (3 to 12 months). Compared to quadriceps rehabilitation, there was moderate evidence that indicated proximal rehabilitation decreased pain in the short and medium terms and also improved function in the medium term. Limited evidence was found to support proximal rehabilitation's ability to improve function, increase isometric hip strength, decrease knee valgus while running, or decrease pain in the long term (> 12 months).
Conclusions: Based on the evidence found in the review, proximal rehabilitation should be included in a conservative treatment of patellofemoral pain. Combining proximal with traditional quadriceps rehabilitation reduces more pain and improves function in 1 year, which suggests there is a short-, medium-, and possibly long-term value for this rehabilitation protocol. The benefits of using multi-muscle group rehabilitation protocols are faster reductions in pain and earlier improved function.
Summary: Patellofemoral pain due to overuse is cited as the most common musculoskeletal injury for physically active individuals at rates between 3% and 20% regardless of age, sex, or activity background.1,2 The factors suggested to contribute to patellofemoral pain syndrome included patellar maltracking from proximal and distal muscle imbalances or weakness, overuse, soft tissue tightness, and poor lower limb alignment.2,3 Biomechanics are also a large part of patellofemoral pain issues, because hip adduction kinematics adversely stress the knee during movement.4 Initial treatment of patellofemoral pain syndrome should include conservative treatments such as relative rest, ice, non-steroidal anti-inflammatory drugs, and specific exercise programs. Conservative treatment involves exercise programs to reduce symptoms and correct potential factors that cause patellofemoral pain. Traditionally, research has indicated conservative treatments should include increasing quadriceps muscle function and strength to resolve patellofemoral problems.1 Recent studies have indicated patellofemoral pain is also related to reduced hip strength and core endurance, which ultimately causes abnormal patellofemoral joint kinematics and a greater load on the patellofemoral joint.1–5
Several randomized controlled trials and cohort studies were performed to compare outcomes of traditional knee-focused rehabilitation protocols with hip and core rehabilitation protocols. Ferber et al.1 found that using knee, hip, and core protocols together produced noticeable improvements in patellofemoral pain and strength. All rehabilitation protocols produce improvements, but hip and core protocols result in an earlier reduction in pain and more strength gains overall than knee-only rehabilitation protocols, which occur over a 6-week period.1 Similar conclusions were made by Peters and Tyson,3 who found that proximal exercise protocols reduced pain and improved function in every study analyzed for their systematic review, as opposed to 80% reduced pain and 75% improved function in knee-only protocols.
De Oliveira Silva et al.4 found that proximal muscles are important for stair climbing mechanics because the stronger hip musculature assists knee flexion by decreasing the load through the knee. This evidence indicates that proximal interventions targeting hip and pelvic musculature in addition to the knee provide more consistent outcomes than knee-only interventions. Consistencies in rehabilitation protocols give clinicians more certainty in patient outcomes and improvements, which creates efficiency in their care.
The systematic review with meta-analysis suggested proximal, hip, and core activation through exercise significantly reduced pain and improved function sooner than knee-only focused rehabilitation.2 Additionally, the systematic review supported that the improvements were significantly greater in the short and medium terms of rehabilitation. Too few studies have been performed to provide strong enough evidence to support hip and core rehabilitations having greater effects than knee-only rehabilitation plans in the long term. Availability is limited for evidence supporting the long-term effects of proximal rehabilitation protocols, a known limitation by the researchers. These findings indicate that a weak musculature proximal to the knee, mainly the hip and core, has a connection to a lack of improvement when using traditional rehabilitation protocols that solely focus on the knee for patellofemoral pain.2
Conservative treatment interventions for patellofemoral pain should include strength, strength-endurance, and neuromuscular activity exercises of the proximal musculature.2 Although traditional protocols for patellofemoral rehabilitation are effective, combining hip and core exercises with quadriceps rehabilitation has improved pain and function in the long term.2,5 These exercises should be included in clinical practice for the best possible patient outcomes during rehabilitation, especially because the primary goals for many patellofemoral pain rehabilitation plans are pain reduction and functional improvements. Table 1 provides a comprehensive list of the articles, participants, and main outcomes of the studies used in this article. Further research is needed to determine the most appropriate and effective protocol design that includes proximal exercises, because the current literature does not detail specific exercises or timelines in their protocols. Identifying specific exercise type, load, and dose will help to improve patient outcomes and specify clinician care to preserve time.
- Ferber R, Bolgla L, Earl-Boehm JE, Emery C, Hamstra-Wright K. Strengthening of the hip and core versus knee muscles for the treatment of patellofemoral pain: a multicenter randomized controlled trial. J Athl Train. 2015;50:366–377. doi:10.4085/1062-6050-49.3.70 [CrossRef]
- Lack S, Barton C, Sohan O, Crossley K, Morrissey D. Proximal muscle rehabilitation is effective for patellofemoral pain: a systematic review with meta-analysis. Br J Sports Med. 2015;49:1365–1376. doi:10.1136/bjsports-2015-094723 [CrossRef]
- Peters JS, Tyson NL. Proximal exercises are effective in treating patellofemoral pain syndrome: a systematic review. Int J Sports Phys Ther. 2013;8:689–700.
- de Oliveira Silva D, Barton CJ, Pazzinatto MF, Briani RV, de Azevedo FM. Proximal mechanics during stair ascent are more discriminate of females with patellofemoral pain than distal mechanics. Clin Biomech (Bristol, Avon). 2016;35:56–61. doi:10.1016/j.clinbiomech.2016.04.009 [CrossRef]
- Witrouw E, Callaghan MJ, Stefanik JJ, et al. Patellofemoral pain: consensus statement from the 3rd International Patellofemoral Pain Research Retreat held in Vancouver, September 2013. Br J Sports Med. 2014;48:411–414. doi:10.1136/bjsports-2014-093450 [CrossRef]
|Author||Study Type/Participants||Main Findings||Intervention|
|Ferber et al. (2015)||Randomized controlled trial; 199 participants with patellofemoral pain||Both hip and knee rehabilitation groups produced improvements in pain, function, and strength over 6 weeks; the hip protocol resulted in earlier resolution of pain and greater gains in strength compared to the knee protocol||Random assignment to 6-week knee (quad strengthening) or hip (hip and core strengthening) protocol|
|Lack et al. (2015)||Systematic review and meta-analysis; 14 studies||Proximal rehabilitation combined with quadriceps rehabilitation decreased pain and improved function in the short term and was found to improve function at 1 year after intervention||Not applicable|
|Peters & Tyson (2013)||Systematic review; 8 studies||Proximal interventions provide consistent pain relief and improved function in the short and long terms||Not applicable|
|de Oliveira et al. (2016)||Case–control study; 67 participants (36 with patellofemoral pain, 31 asymptomatic controls)||Proximal musculature plays a significant role in knee kinematics, suggesting proximally targeted interventions may be the most important consideration in rehabilitation for patients with patellofemoral pain||3-D kinematic analysis during stair ascent analyzing peak rear-foot eversion, hip adduction, and knee flexion|