Christian J Barton

A comparison of foot kinematics in people with normal- and flat-arched feet using the Oxford Foot Model

Foot posture is thought to influence predisposition to overuse injuries of the lower limb. Although the mechanisms underlying this proposed relationship are unclear, it is thought that altered foot kinematics may play a role. Therefore, this study was designed to investigate differences in foot motion between people with normal- and flat-arched feet using the Oxford Foot Model (OFM). Foot posture in 19 participants was documented as normal-arched (n=10) or flat-arched (n=9) using a foot screening protocol incorporating measurements from weightbearing antero-posterior and lateral foot radiographs. Differences between the groups in triplanar motion of the tibia, rearfoot and forefoot during walking were evaluated using a three-dimensional motion analysis system incorporating a multi-segment foot model (OFM). Participants with flat-arched feet demonstrated greater peak forefoot plantar-flexion (-13.7° ± 5.6° vs -6.5° ± 3.7°; p=0.004), forefoot abduction (-12.9° ± 6.9° vs -1.8° ± 6.3°; p=0.002), and rearfoot internal rotation (10.6° ± 7.5° vs -0.2°± 9.9°; p=0.018) compared to those with normal-arched feet. Additionally, participants with flat-arched feet demonstrated decreased peak forefoot adduction (-7.0° ± 9.2° vs 5.6° ± 7.3°; p=0.004) and a trend towards increased rearfoot eversion (-5.8° ± 4.4° vs -2.5° ± 2.6°; p=0.06). These findings support the notion that flat-arched feet have altered motion associated with greater pronation during gait; factors that may increase the risk of overuse injury.

Foot and Ankle Characteristics in Patellofemoral Pain Syndrome: A Case Control and Reliability Study

STUDY DESIGN Case-control and reliability study. OBJECTIVES To compare foot and ankle characteristics between individuals with and without patellofemoral pain syndrome (PFPS) and to identify reliable weight-bearing foot and ankle measurements for use in future research on PFPS. BACKGROUND PFPS is a common presentation to sports medicine and orthopaedic clinics. Characteristics of the foot and ankle are often linked with PFPS development, although evidence to support this link is equivocal and there is a lack of consensus on how best to evaluate these characteristics. METHODS A variety of weight-bearing foot and ankle measurements were evaluated by 3 raters of varying experience in 20 individuals with PFPS and 20 controls matched by age, sex, height, and body mass. Between-group comparisons were made for each measurement using data from an experienced podiatrist blinded to group assignment of the participants. Intrarater and interrater reliability was compared between all measurements using the first 15 participants from each group. RESULTS Between-group comparisons showed that the individuals in the PFPS group had a more pronated foot posture when assessed by the foot posture index and longitudinal arch angle, and for all measurements relative to subtalar joint neutral. Foot posture index, normalized navicular drop, and calcaneal angle relative to subtalar joint neutral measurements also possessed high reliability in both groups when used by experienced raters. Reliability was not influenced by rater experience or the presence of PFPS for relaxed-stance foot posture measurements. Both tester inexperience and the presence of PFPS reduced reliability for all measurements of foot posture relative to subtalar joint neutral and measurement of weight-bearing ankle dorsiflexion. CONCLUSION The foot posture index, normalized navicular drop, and calcaneal angle relative to subtalar joint neutral are all reliable and sensitive to group differences when used in a population with PFPS. Individuals with PFPS possess a more pronated foot posture and increased foot mobility compared to controls. Prospective evaluation of these measurements is now required to determine whether they contribute to the development of PFPS. J Orthop Sports Phys Ther 2010;40(5):286-296, Epub 12 April 2010. doi:10.2519/jospt.2010.3227.

Gluteal muscle activity and patellofemoral pain syndrome: a systematic review

Objective There is growing evidence to support the association of gluteal muscle strength deficits in individuals with patellofemoral pain syndrome (PFPS) and the effectiveness of gluteal strengthening when treating PFPS. In additiona, an impressive body of work evaluating gluteal electromyography (EMG) has recently emerged, further supporting the importance of gluteal muscle function in PFPS. This systematic review synthesises these EMG findings in order to better understand the role of gluteal muscle activity in the aetiology, presentation and management of PFPS. Methods MEDLINE, EMBASE, CINAHL, Web of Knowledge and Google Scholar databases were searched in September 2011 for prospective and case–control studies evaluating the association of gluteal EMG with PFPS. Two independent reviewers assessed each paper for inclusion and quality. Means and SDs were extracted from each included study to allow effect size calculations and comparison of results. Results Ten case–control, but no prospective studies were identified. Moderate-to-strong evidence indicates gluteus medius (GMed) activity is delayed and of shorter duration during stair negotiation in PFPS sufferers. In addition, limited evidence indicates GMed activity is delayed and of shorter duration during running, and gluteus maximus (GMax) activity is increased during stair descent. Conclusions Delayed and shorter duration of GMed EMG may indicate impaired ability to control frontal and transverse plane hip motion. Further research evaluating the value of gluteal muscle activity screening in identifying individuals most likely to develop PFPS, and the effectiveness of interventions targeting changes to gluteal muscle activation patterns is needed.

Development and evaluation of a tool for the assessment of footwear characteristics.

BackgroundFootwear characteristics have been linked to falls in older adults and children, and the development of many musculoskeletal conditions. Due to the relationship between footwear and pathology, health professionals have a responsibility to consider footwear characteristics in the etiology and treatment of various patient presentations. In order for health professionals and researchers to accurately and efficiently critique an individuals footwear, a valid and reliable footwear assessment tool is required. The aim of this study was to develop a simple, efficient, and reliable footwear assessment tool potentially suitable for use in a range of patient populations.MethodsConsideration of previously published tools, other footwear related literature, and clinical considerations of three therapists were used to assist in the development of the tool. The tool was developed to cover fit, general features, general structure, motion control properties, cushioning, and wear patterns. A total of 15 participants (who provided two pairs of shoes each) were recruited, and assessment using the scale was completed on two separate occasions (separated by 1 – 3 weeks) by a physiotherapist and a podiatrist on each participants dominant foot. Intra-rater and inter-rater reliability were evaluated using intra-class correlation coefficients (ICCs) (model 2, 1) and the 95% limits of agreement (95% LOAs) for continuous items, and percentage agreement and kappa (κ) statistics for categorical items.ResultsAll categorical items demonstrated high percentage agreement statistic for intra-rater (83 – 100%) and inter-rater (83 – 100%) comparisons. With the exception of last shape and objective measures used to categorise the adequacy of length, excellent intra-rater (ICC = 0.91 – 1.00) and inter-rater reliability (ICC = 0.90 – 1.00) was indicated for continuous items in the tool, including the motion control properties scale (0.91 – 0.95).ConclusionA comprehensive footwear assessment tool with good face validity has been developed to assist future research and clinical footwear assessment. Generally good reliability amongst all items indicates that the tool can be used with confidence in research and clinical settings. Further research is now required to determine the clinical validity of each item in various patient populations.

Is hip strength a risk factor for patellofemoral pain? A systematic review and meta-analysis

Objective To evaluate and synthesise the literature on hip strength among patients with patellofemoral pain (PFP) to address the following: (1) differentiate between hip strength as a risk factor and associated deficit in PFP; (2) describe hip strength in men and women with PFP across different age ranges; (3) investigate the effects of hip strengthening on biomechanical knee variables associated with PFP development. Methods MEDLINE, CINAHL, Web of Science, SportDiscus and Google Scholar were searched in November 2013 for studies investigating hip strength among patients with PFP. Two reviewers independently assessed papers for inclusion and quality. Means and SDs were extracted from each included study to allow effect size calculations and comparisons of results. Results Moderate-to-strong evidence from prospective studies indicates no association between isometric hip strength and risk of developing PFP. Moderate evidence from cross-sectional studies indicates that men and women with PFP have lower isometric hip musculature strength compared to pain-free individuals. Limited evidence indicates that adolescents with PFP do not have the same strength deficits as adults with PFP. Conclusions This review highlights a possible discrepancy between prospective and cross-sectional research. Cross-sectional studies indicate that adult men and women with PFP appear to have lower hip strength compared to pain-free individuals. Contrary to this, a limited number of prospective studies indicate that there may be no association between isometric hip strength and risk of developing PFP. Therefore, reduced hip strength may be a result of PFP rather than the cause.

The efficacy of foot orthoses in the treatment of individuals with patellofemoral pain syndrome: a systematic review

Patellofemoral pain syndrome (PFPS) is a highly prevalent condition, often reducing functional performance and being linked to osteoarthritis development later in life. Prescribing foot orthoses is often advocated, although the link between foot mechanics and PFPS development remains unclear. This systematic review was conducted to summarize and critique the existing evidence for the efficacy of foot orthoses in individuals with PFPS and to provide guidance for future research evaluating foot orthoses in individuals with PFPS. A comprehensive search of MEDLINE, EMBASE, CINAHL® and Current Contents revealed 138 citations for review. Two of the authors independently reviewed and assessed each citation for inclusion and quality using a modified version of the quality assessment scale for randomized controlled trials in PFPS designed by Bizzini and colleagues. A total of seven studies were included in the final review. The review found limited evidence that prefabricated foot orthoses may reduce the range of transverse plane knee rotation and provide greater short-term improvements in individuals with PFPS compared with flat inserts. Findings also indicated that combining physiotherapy with prefabricated foot orthoses may be superior to prefabricated foot orthoses alone. Further research is now needed to establish the mechanisms behind the efficacy of foot orthoses and to identify individuals with PFPS who are most likely to benefit from prescription of foot orthoses. A comparison of the efficacy between prefabricated and customized foot orthoses is also needed.

The Effectiveness of Extracorporeal Shock Wave Therapy in Lower Limb Tendinopathy: A Systematic Review

Background: There is accumulating evidence for the effectiveness of extracorporeal shock wave therapy (ESWT) when treating lower limb tendinopathies including greater trochanteric pain syndrome (GTPS), patellar tendinopathy (PT), and Achilles tendinopathy (AT). Purpose: To evaluate the effectiveness of ESWT for lower limb tendinopathies. Study Design: Systematic review and meta-analysis. Methods: PubMed (Medline), Embase, Web of Knowledge, Cochrane, and CINAHL were searched from inception to February 2013 for studies of any design investigating the effectiveness of ESWT in GTPS, PT, and AT. Citation tracking was performed using PubMed and Google Scholar. Animal and non–English language studies were excluded. A quality assessment was performed by 2 independent reviewers, and effect size calculations were computed when sufficient data were provided. Results: A total of 20 studies were identified, with 13 providing sufficient data to compute effect size calculations. The energy level, number of impulses, number of sessions, and use of a local anesthetic varied between studies. Additionally, current evidence is limited by low participant numbers and a number of methodological weaknesses including inadequate randomization. Moderate evidence indicates that ESWT is more effective than home training and corticosteroid injection in the short (<12 months) and long (>12 months) term for GTPS. Limited evidence indicates that ESWT is more effective than alternative nonoperative treatments including nonsteroidal anti-inflammatory drugs, physical therapy, and an exercise program and equal to patellar tenotomy surgery in the long term for PT. Moderate evidence indicates that ESWT is more effective than eccentric loading for insertional AT and equal to eccentric loading for midportion AT in the short term. Additionally, there is moderate evidence that combining ESWT and eccentric loading in midportion AT may produce superior outcomes to eccentric loading alone. Conclusion: Extracorporeal shock wave therapy is an effective intervention and should be considered for GTPS, PT, and AT particularly when other nonoperative treatments have failed.

The ‘Best Practice Guide to Conservative Management of Patellofemoral Pain’: incorporating level 1 evidence with expert clinical reasoning

Importance Patellofemoral pain (PFP) is both chronic and prevalent; it has complex aetiology and many conservative treatment options. Objective Develop a comprehensive contemporary guide to conservative management of PFP outlining key considerations for clinicians to follow. Design Mixed methods. Methods We synthesised the findings from six high-quality systematic reviews to September 2013 with the opinions of 17 experts obtained via semistructured interviews. Experts had at least 5 years clinical experience with PFP as a specialist focus, were actively involved in PFP research and contributed to specialist international meetings. The interviews covered clinical reasoning, perception of current evidence and research priorities. Results Multimodal intervention including exercise to strengthen the gluteal and quadriceps musculature, manual therapy and taping possessed the strongest evidence. Evidence also supports use of foot orthoses and acupuncture. Interview transcript analysis identified 23 themes and 58 subthemes. Four key over-arching principles to ensure effective management included—(1) PFP is a multifactorial condition requiring an individually tailored multimodal approach. (2) Immediate pain relief should be a priority to gain patient trust. (3) Patient empowerment by emphasising active over passive interventions is important. (4) Good patient education and activity modification is essential. Future research priorities include identifying risk factors, testing effective prevention, developing education strategies, evaluating the influence of psychosocial factors on treatment outcomes and how to address them, evaluating the efficacy of movement pattern retraining and improving clinicians’ assessment skills to facilitate optimal individual prescription. Conclusions and relevance Effective management of PFP requires consideration of a number of proven conservative interventions. An individually tailored multimodal intervention programme including gluteal and quadriceps strengthening, patellar taping and an emphasis on education and activity modification should be prescribed for patients with PFP. We provide a ‘Best Practice Guide to Conservative Management of Patellofemoral Pain’ outlining key considerations.

The relationship between rearfoot, tibial and hip kinematics in individuals with patellofemoral pain syndrome.

BACKGROUND Excessive rearfoot eversion is thought to be a risk factor for patellofemoral pain syndrome development, based on theoretical rationale linking it to greater tibial internal rotation and hip adduction. This study aimed to establish the relationship of rearfoot eversion with tibial internal rotation and hip adduction during walking in individuals with and without patellofemoral pain syndrome. METHODS Twenty-six individuals with patellofemoral pain syndrome and 20 controls (18-35years) participated. Each underwent instrumented three-dimensional motion analysis during over-ground walking. Pearsons correlation coefficients (r) were calculated to establish the relationship of rearfoot eversion with tibial internal rotation and hip adduction (peak and range of motion). FINDINGS Greater peak rearfoot eversion was associated with greater peak tibial internal rotation in the patellofemoral pain syndrome group (r=0.394, P=0.046). Greater rearfoot eversion range of motion was associated with greater hip adduction range of motion in the patellofemoral pain syndrome (r=0.573, P=0.002) and control (r=0.460, P=0.041) groups; and greater peak hip adduction in the control group (r=0.477, P=0.033). INTERPRETATION Associations between greater rearfoot eversion and greater hip adduction indicate that interventions targeted at the foot or hip in individuals with patellofemoral pain syndrome may have similar overall effects on lower limb motion and clinical outcomes. The relationship between rearfoot eversion and tibial internal rotation identified in the patellofemoral pain syndrome group may be related to aetiology. However, additional prospective research is needed to confirm this.

2016 Patellofemoral pain consensus statement from the 4th International Patellofemoral Pain Research Retreat, Manchester. Part 2: recommended physical interventions (exercise, taping, bracing, foot orthoses and combined interventions)

Patellofemoral pain affects physically active and sedentary individuals, accounting for 11–17% of knee pain presentations to general practice1 ,2 and 25–40% of all knee problems seen in a sports injury clinic.3 ,4 Patellofemoral pain is characterised by anterior knee pain associated with activities such as squatting, rising from sitting and stair ambulation. While traditionally viewed as self-limiting, increasing research data suggest that patellofemoral pain is often recalcitrant and can persist for many years,5–8 and may cause a decline in sports participation.8 ,9 Despite its high prevalence among active individuals9–12 and frequent presentations for treatment, there are few published guidelines to help clinicians choose the appropriate evidence-based treatment for patellofemoral pain. The most recent and relevant paper from Barton and colleagues13 combined systematic review findings with qualitative interviews from expert clinicians to provide a clinically relevant synthesis, covering the literature up to September 2013. At the International Patellofemoral Pain Research Retreat in Manchester 2015, we held a consensus meeting to update the current evidence base and produce consensus-based recommendations regarding treatment for patellofemoral pain. All retreat registrants were active researchers in patellofemoral pain and presented their research findings. Many of the world leading researchers (eg, 8 out of the top 10 researchers with the highest number of publications, when the term ‘patellofemoral pain’ was searched in Scopus, February 2016) were in attendance and contributed to the consensus meeting. The consensus meeting during the retreat resulted in recommendations, based on evidence published between January 2010 and June 2015. These recommendations should be combined with information gathered from individual patients, regarding their preferences, experiences, presentation and values, along with the values, expertise and skills of individual practitioners to create a patient-centred treatment approach. ### Literature review CJB searched EMBASE, MEDLINE, CINAHL and Current Contents for systematic reviews …