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Kedroff L1, Ratcliffe C1, Skinner J1
1Kings College London, School of Population Health & Environmental Sciences, London, United Kingdom
Background: Deficits in physical factors such as hip and knee strength and kinematics have been identified in Patellofemoral Pain (PFP) and although there is low but consistent evidence supporting exercise programmes to reduce pain in PFP, it is not clear whether the physical deficits change.
Purpose: This review investigated the effect of exercise programmes for PFP participants on physical factors and pain in comparison with other exercises or control interventions.
Methods: After registering on Prospero, MEDLINE, EMBASE, CINAHL and the Cochrane Central Register of Controlled Trials databases were searched. Inclusion criteria were randomised controlled trials of exercise programmes for PFP participants.
The effect of exercise programmes on hip and knee strength and 3D kinematic data was compared with the effect of other exercise and control interventions. The primary outcomes were change in strength and kinematic data from baseline to post-intervention follow up and secondary outcome was change in pain.
Titles and / or abstracts were screened by two reviewers and the data from eligible studies was extracted. Study quality was assessed using The Cochrane Collaboration Risk of Bias Tool. The study findings were summarised narratively and standardised mean differences (SMD) and 95% confidence intervals (95% CI) were provided for the strength, kinematic and pain outcome data. Meta- analyses were undertaken and data heterogeneity was assessed.
Results: Fourteen studies with 635 participants were included, 5 compared hip with knee muscle strengthening exercises and from pooled data increases in hip (abductor SMD=0.27, 95%CI 0.05-0.50, p=0.02; lateral rotator SMD = 0.16, 95%CI 0.06-0.39, p=0.15) and knee (extensor SMD=0.15, 95%CI -0.09-0.39, p 0.01) strength and reductions in pain (MD=-0.6, 95%CI -1.05-0.19, p 0.01) favoured the hip exercise group. Two studies compared weightbearing versus non-weightbearing exercises; no group difference was found in knee extension strength (SMD=0.00, 95%CI -0.41-0.42, p=0.99) but decreased pain (MD=0.74, 95%CI -0.42-1.90, p=0.21) favoured the weightbearing group. Four studies compared motor control (correcting lower limb movement patterns) with knee +/- hip strengthening exercises and found increased hip abductor strength (SMD=0.50, 95%CI -0.01-1.01, p=0.05) and reduction in pain (MD=-1.41, 95%CI -2.08- -0.74, p 0.01) favoured the motor control group however, increases in hip lateral rotator (SMD = -0.04, 95%CI -0.53-0.45, p=0.87) and knee extensor (SMD=-0.20, 95%CI -0.51-0.11, p=0.20) strength favoured the strengthening group. Two studies investigated kinematics and found increased hip flexion (SMD=0.89, 95%CI 0.37-1.41, p 0.01) and knee adduction (SMD=0.52, 95%CI 0.01-1.01, p=0.04) joint angles favoured the motor control group.
Three studies compared exercise with other interventions (e.g education) and found increased knee extensor strength (SMD=0.87, 95%CI 0.32-1.41, p 0.01) and decreased pain (SMD -1.01, 95%CI -1.51- -0.51, p 0.01) favoured the exercise group.
Conclusion(s): Hip strengthening exercises increase hip and knee strength and decrease pain compared with other exercises and control interventions. Motor control exercises also decrease pain and increase hip abductor strength and hip and knee joint angles. However, findings must be interpreted with some caution due to limited number of high quality studies especially for kinematics and heterogeneity noted.
Implications: The study supports exercise programmes to decrease PFP pain and increase strength.
Keywords: patellofemoral pain, kinematics, muscle strength
Funding acknowledgements: Not applicable
Purpose: This review investigated the effect of exercise programmes for PFP participants on physical factors and pain in comparison with other exercises or control interventions.
Methods: After registering on Prospero, MEDLINE, EMBASE, CINAHL and the Cochrane Central Register of Controlled Trials databases were searched. Inclusion criteria were randomised controlled trials of exercise programmes for PFP participants.
The effect of exercise programmes on hip and knee strength and 3D kinematic data was compared with the effect of other exercise and control interventions. The primary outcomes were change in strength and kinematic data from baseline to post-intervention follow up and secondary outcome was change in pain.
Titles and / or abstracts were screened by two reviewers and the data from eligible studies was extracted. Study quality was assessed using The Cochrane Collaboration Risk of Bias Tool. The study findings were summarised narratively and standardised mean differences (SMD) and 95% confidence intervals (95% CI) were provided for the strength, kinematic and pain outcome data. Meta- analyses were undertaken and data heterogeneity was assessed.
Results: Fourteen studies with 635 participants were included, 5 compared hip with knee muscle strengthening exercises and from pooled data increases in hip (abductor SMD=0.27, 95%CI 0.05-0.50, p=0.02; lateral rotator SMD = 0.16, 95%CI 0.06-0.39, p=0.15) and knee (extensor SMD=0.15, 95%CI -0.09-0.39, p 0.01) strength and reductions in pain (MD=-0.6, 95%CI -1.05-0.19, p 0.01) favoured the hip exercise group. Two studies compared weightbearing versus non-weightbearing exercises; no group difference was found in knee extension strength (SMD=0.00, 95%CI -0.41-0.42, p=0.99) but decreased pain (MD=0.74, 95%CI -0.42-1.90, p=0.21) favoured the weightbearing group. Four studies compared motor control (correcting lower limb movement patterns) with knee +/- hip strengthening exercises and found increased hip abductor strength (SMD=0.50, 95%CI -0.01-1.01, p=0.05) and reduction in pain (MD=-1.41, 95%CI -2.08- -0.74, p 0.01) favoured the motor control group however, increases in hip lateral rotator (SMD = -0.04, 95%CI -0.53-0.45, p=0.87) and knee extensor (SMD=-0.20, 95%CI -0.51-0.11, p=0.20) strength favoured the strengthening group. Two studies investigated kinematics and found increased hip flexion (SMD=0.89, 95%CI 0.37-1.41, p 0.01) and knee adduction (SMD=0.52, 95%CI 0.01-1.01, p=0.04) joint angles favoured the motor control group.
Three studies compared exercise with other interventions (e.g education) and found increased knee extensor strength (SMD=0.87, 95%CI 0.32-1.41, p 0.01) and decreased pain (SMD -1.01, 95%CI -1.51- -0.51, p 0.01) favoured the exercise group.
Conclusion(s): Hip strengthening exercises increase hip and knee strength and decrease pain compared with other exercises and control interventions. Motor control exercises also decrease pain and increase hip abductor strength and hip and knee joint angles. However, findings must be interpreted with some caution due to limited number of high quality studies especially for kinematics and heterogeneity noted.
Implications: The study supports exercise programmes to decrease PFP pain and increase strength.
Keywords: patellofemoral pain, kinematics, muscle strength
Funding acknowledgements: Not applicable
Topic: Musculoskeletal: lower limb; Sport & sports injuries
Ethics approval required: No
Institution: Kings College London
Ethics committee: Biomedical Sciences, Dentistry, Medicine, Natural Sciences Research Ethics Committee
Reason not required: Ethical approval was not required as this is a systemic review using data from the public domain. Our research ethics committee advises that projects involving the accessing and further analysis of fully anonymised pre-existing data do not require ethical clearance.
All authors, affiliations and abstracts have been published as submitted.
