Proximal and distal influences on hip and knee kinematics in runners with patellofemoral pain during a prolonged run

Relationship between explosive muscle strength and medial longitudinal arch of the foot

BACKGROUND

There has been a suggested link between muscle strength and arch type of the foot. However, a distinct cause and effect dependence has yet to be established. The purpose of this study was to compare the outcomes from selected explosive strength tests with different arch heights.

MATERIAL AND METHODS

The medial longitudinal arch (MLA) was measured using a Clarke's angle method. Five hundred seventy-four subjects (n = 574) participated in this study and were divided into three arch height groups and three muscle strength groups, respectively. To evaluate the association between longitudinal arch of the foot with the explosive power of lower limb muscles, Chi-square (χ²) test was used.

RESULTS

Arch heights were not significantly related to explosive muscle strength.

CONCLUSIONS

Arch measurement was ineffective in accounting for the observed variability in the explosive strength among young adults.

CLINICAL RELEVANCE

This data may be useful in evaluating patients with painful flat feet and any strength deficits they may have.

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.

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.

Femur rotation and patellofemoral joint kinematics: a weight-bearing magnetic resonance imaging analysis

STUDY DESIGN

Controlled laboratory study using a cross-sectional design.

OBJECTIVES

To compare patellofemoral joint kinematics, femoral rotation, and patella rotation between females with patellofemoral pain (PFP) and pain-free controls using weight-bearing kinematic magnetic resonance imaging.

BACKGROUND

Recently, it has been recognized that patellofemoral malalignment may be the result of femoral motion as opposed to patella motion.

METHODS

Fifteen females with PFP and 15 pain-free females between the ages of 18 and 45 years participated in this study. Kinematic imaging of the patellofemoral joint was performed using a vertically open magnetic resonance imaging system. Axial-oblique images were obtained using a fast gradient-echo pulse sequence. Images were acquired at a rate of 1 image per second while subjects performed a single-limb squat. Measures of femur and patella rotation (relative to the image field of view), lateral patella tilt, and lateral patella displacement were made from images obtained at 45 degrees , 30 degrees , 15 degrees , and 0 degrees of knee flexion. Group differences were assessed using a mixed-model analysis of variance with repeated measures.

RESULTS

When compared to the control group, females with PFP demonstrated significantly greater lateral patella displacement at all angles evaluated and significantly greater lateral patella tilt at 30 degrees , 15 degrees , and 0 degrees of knee flexion. Similarly, greater medial femoral rotation was observed in the PFP group at 45 degrees , 15 degrees , and 0 degrees of knee flexion when compared to the control group. No group differences in patella rotation were found.

CONCLUSION

Altered patellofemoral joint kinematics in females with PFP appears to be related to excessive medial femoral rotation, as opposed to lateral patella rotation. Our results suggest that the control of femur rotation may be important in restoring normal patellofemoral joint kinematics. J Orthop Sports Phys Ther 2010;40(5):277-285, Epub 12 March 2010. doi:10.2519/jospt.2010.3215.

Eccentric hip muscle function in females with and without patellofemoral pain syndrome

CONTEXT

Patellofemoral pain syndrome (PFPS) is a common knee condition in athletes. Recently, researchers have indicated that factors proximal to the knee, including hip muscle weakness and motor control impairment, contribute to the development of PFPS. However, no investigators have evaluated eccentric hip muscle function in people with PFPS.

OBJECTIVE

To compare the eccentric hip muscle function between females with PFPS and a female control group.

DESIGN

Cross-sectional study.

SETTING

Musculoskeletal laboratory.

PATIENTS OR OTHER PARTICIPANTS

two groups of females were studied: a group with PFPS (n = 10) and a group with no history of lower extremity injury or surgery (n = 10).

INTERVENTION(S)

Eccentric torque of the hip musculature was evaluated on an isokinetic dynamometer.

MAIN OUTCOME MEASURE(S)

Eccentric hip abduction, adduction, and external and internal rotation peak torque were measured and expressed as a percentage of body mass (Nm/kg x 100). We also evaluated eccentric hip adduction to abduction and internal to external rotation torque ratios. The peak torque value of 5 maximal eccentric contractions was used for calculation. Two-tailed, independent-samples t tests were used to compare torque results between groups.

RESULTS

Participants with PFPS exhibited much lower eccentric hip abduction (t(18) = -2.917, P = .008) and adduction (t(18) = -2.764, P = .009) peak torque values than did their healthy counterparts. No differences in eccentric hip external (t(18) = 0.45, P = .96) or internal (t(18) = -0.742, P = .47) rotation peak torque values were detected between the groups. The eccentric hip adduction to abduction torque ratio was much higher in the PFPS group than in the control group (t(18) = 2.113, P = .04), but we found no difference in the eccentric hip internal to external rotation torque ratios between the 2 groups (t(18) = -0.932, P = .36).

CONCLUSIONS

Participants with PFPS demonstrated lower eccentric hip abduction and adduction peak torque and higher eccentric adduction to abduction torque ratios when compared with control participants. Thus, clinicians should consider eccentric hip abduction strengthening exercises when developing rehabilitation programs for females with PFPS.

Kinematic gait characteristics associated with patellofemoral pain syndrome: a systematic review

Development of patellofemoral pain syndrome (PFPS) is considered to be multifactorial. The aims of this systematic review were to (i) summarise and critique the body of literature addressing kinematic gait characteristics associated with PFPS; and (ii) provide recommendations for future research addressing kinematic gait characteristics associated with PFPS. A comprehensive search of MEDLINE, EMBASE, CINAHL, and Current Contents revealed 561 citations for review. Each citation was assessed for inclusion and quality using a modified version of the 'Quality Index' and a novel inclusion/exclusion criteria checklist by two independent reviewers. A total of 24 studies were identified. No prospective studies with adequate data to complete effect size calculations were found. Quality of included case-control studies varied, with a number of methodological issues identified. Heterogeneity between studies made meta-analysis inappropriate. Reductions in gait velocity were indicated during walking, ramp negotiation, and stair negotiation in individuals with PFPS. Findings indicated delayed timing of peak rearfoot eversion and increased rearfoot eversion at heel strike transient during walking; and delayed timing of peak rearfoot eversion, increased rearfoot eversion at heel strike, reduced rearfoot eversion range, greater knee external rotation at peak knee extension moment, and greater hip adduction during running in individuals with PFPS. There is a clear need for prospective evaluation of kinematic gait characteristics in a PFPS population to distinguish between cause and effect. Where possible, future PFPS case-control studies should consider evaluating kinematics of the knee, hip and foot/ankle simultaneously with larger participant numbers. Completing between sex comparisons when practical and considering spatiotemporal gait characteristics during methodological design and data analysis is also recommended.

Patellofemoral knee pain in an adult with radiographic osteoarthritis and human immunodeficiency virus infection

STUDY DESIGN

Resident's case problem.

BACKGROUND

Kaposi's sarcoma (KS) is the most common form of cancer in patients with human immunodeficiency virus (HIV) infection. Although KS is often initially asymptomatic, this neoplasm may progress to affect multiple organ systems, including structures of the musculoskeletal system, which can produce symptoms similar to those associated with common orthopaedic conditions. This resident's case problem describes the evaluation and differential diagnosis of a 45-year-old male with HIV and KS, referred to physical therapy with an initial diagnosis of radiographic osteoarthritis (OA) and patellofemoral pain syndrome (PFPS) of the left knee. His primary complaint was knee pain during end range knee flexion.

DIAGNOSIS

The history, systems review, and examination suggested a source of pain of a nonorthopaedic origin. Differential examination ruled out clinical OA, PFPS, ligament/cartilage derangement, and tendonitis. Avascular necrosis of the medial femoral condyle was also considered as a possible source of pain. Recent blood tests indicated a high viral load and low CD4 count, which might have increased susceptibility to opportunistic infections or KS tumor progression. The patient was referred back to his physician for additional follow-up. Magnetic resonance imaging (MRI) of the knees were consistent with a systemic inflammatory process such as KS. A true-cut biopsy was subsequently scheduled, which confirmed KS lesions at the left knee.

DISCUSSION

Physical therapists who manage orthopaedic conditions should be aware of the disablement that may result from acquired immunodeficiency syndrome-related KS. A thorough joint-specific examination, with a broad differential diagnosis, should be employed for patients having known systemic diseases.

LEVEL OF EVIDENCE

Differential diagnosis, level 4.