Faculty Bibliography

Musculoskeletal conditions of the foot and ankle are an important public health challenge due to their increasing incidence combined with their substantial negative impact on patients' quality of life. Non-pharmacological treatments serve as the first line of treatment and are frequently used for patients with musculoskeletal conditions of the foot and ankle. This review provides a summary of the assessments and non-invasive treatment options based upon available evidence. Recent studies show that individuals with foot and ankle pain have multiple co-existing impairments in alignment, motion, load distribution and muscle performance that may be evident in static and/or dynamic tasks. In addition, both clinical and epidemiological studies support the inter-dependence between the foot and proximal joints. For instance, aberrant foot structure has been linked to foot osteoarthritis (OA), as well as OA and pain at the knee and hip. Most recently, advances in motion capture technology and plantar load distribution measurement offer opportunities for precise dynamic assessments of the foot and ankle. In individuals with musculoskeletal conditions of the foot and ankle, the chief objectives of treatment are to afford pain relief, restore mechanics (alignment, motion and/or load distribution) and return the patient to their desired level of activity participation. Given that most patients present with multiple impairments, combinational therapies that target foot-specific as well as global impairments have shown promising results. In particular, in individuals with rheumatoid arthritis and other rheumatic diseases, comprehensive rehabilitation strategies including early detection, foot-based interventions (such as orthoses) and wellness-based approaches for physical activity and self-management have been successful. While significant improvements have been made in the last decade to the assessment and treatment of foot and ankle conditions, few randomised clinical trials specifically have investigated patients with foot or ankle conditions to provide global insights into this area. Consequently, current recommendations vary based upon the scope of studies presented in this review as well as the strength of studies. This review indicates a need for more in-depth investigations into the components of assessment and treatment options for foot and ankle musculoskeletal conditions.

Regional plantar pressures during stair walking may be injurious in at risk populations. However, limited data are available examining the reliability of plantar pressure data collected during stair walking. The aims of this study were three fold; to assess the reliability of the plantar pressure data recorded during stair walking, to assess the effects of level ground and stair walking on plantar loading, and to develop regression equations to predict regional plantar pressures in stair walking from those collected on level ground. Fifteen subjects without conditions affecting their ability to walk on level surfaces or stairs were recruited. Each participant performed at least 10 steps in level ground and stair walking while plantar pressure data were recorded in six foot regions. Reliability was assessed using Intraclass Correlation Coefficient. A repeated measures ANOVA was used to assess the effect of activity on plantar pressure, and a linear regression was used to predict forefoot loading during stair walking. A reliability of 0.9 was achieved within 10 steps in all foot regions, with the forefoot requiring fewer steps. Plantar pressures were influenced by both, foot region and activity, with the heel and forefoot regions generally experiencing lower peak pressures and maximal forces during stair walking than level ground walking. The regression equations predicting peak pressure during stair walking accounted for between 37% and 70% of the variance of the stair walking data. These findings establish the reliability of plantar pressure data collected during stair walking. Future studies should investigate these parameters in clinical populations.

BACKGROUND: Knee pain and early arthrosis have emerged as significant problems in young adults with myelomeningocele (MMC). The purpose of our study was to examine kinematics and kinetics during gait in symptomatic and asymptomatic limbs of children with an MMC to better understand the factors that may predispose individuals with an MMC to potentially debilitating knee problems. METHODS: Seven children with L3-L4 level MMC and 8 age-matched typically-developing control children participated in this study. Three-dimensional kinematic and kinetic data were obtained bilaterally during gait. A custom-designed femoral tracking device, with established reliability and validity was used to track the thigh. The limbs in an MMC group were subdivided into 2 subgroups (n=6 and 8, symptomatic and asymptomatic, respectively) based on history of pain at the knee joint after walking/weight bearing activity in the last 6 months. An 1-way analysis of variance with post hoc Bonferroni adjustments was used to compare lower extremity kinematic and kinetic variables between symptomatic, asymptomatic, and control limbs. The Pearson product moment correlation (r) was used to assess the relationship between variables of interest. RESULTS: Symptomatic limbs showed increased knee flexion in stance (P=0.01) compared with asymptomatic limbs. Symptomatic limbs showed trends toward increased knee extension, adduction, and internal rotation moments (P=0.031, P=0.025, and P=0.024, respectively) compared with asymptomatic limbs. Hip internal rotation was positively associated with knee internal rotation moment (r=0.93, P=0.008 and r=0.76, P=0.08 in symptomatic and asymptomatic limbs, respectively) and increased knee adduction moment (r=0.84, P=0.03 and r=0.91, P=0.01 in symptomatic and asymptomatic limbs, respectively). CONCLUSIONS: Symptomatic limbs in children with an MMC showed increased knee flexion and trends toward higher extension, adduction, and internal rotation moments. Increased knee flexion accompanied by inadequate control of hip transverse kinematics may have significant implications for knee joint loading in this population. LEVEL OF EVIDENCE: Level 4 (Case series with controls, motion laboratory gait analysis).

OBJECTIVE:While recent evidence suggests that foot pain may be related to mechanical stress, quantitative data elucidating the role of regional plantar loading in foot pain in individuals with midfoot osteoarthritis (OA) are lacking. Therefore the authors' objective is to examine regional plantar loading and self-reported foot pain in patients with midfoot OA compared to asymptomatic, matched control subjects. METHOD/METHODS:Fifty subjects, 30 patients with midfoot OA and 20 control subjects participated in this study. Self-reported function was assessed using the Foot Function Index-Revised (FFI-R). Plantar loading during barefoot walking at self-selected, monitored walking speed was quantified using an EMED pedobarograph. Between-group differences in FFI-R score and plantar loading were assessed using an independent t-test and the Mann-Whitney U-test respectively. The relationship between FFI-R score and plantar loading was assessed using Spearman rank correlation. A k-means cluster analysis was used to identify potential sub-groups of patients through regional plantar loading. RESULTS:The key findings of this study showed that patients with midfoot OA reported significantly higher FFI-R scores, and higher heel and medial midfoot average pressure compared to control subjects. Medial midfoot pressure-time integral was positively associated with FFI-R Pain Subscale Score (r=0.524, P<0.01). Based on the adequacy index, the two-cluster solution was deemed most appropriate. CONCLUSION/CONCLUSIONS:This study demonstrated that patients with midfoot OA sustain increased magnitude and duration of regional plantar loading during walking compared to matched control subjects. Our findings support the theory that regional mechanical stress may be associated with symptoms in patients with midfoot OA. Future studies should assess whether interventions designed to reduce plantar loading are effective in relieving foot pain, and preventing progression of symptoms in patients with midfoot OA.

The purpose of our study was to examine 1st metatarsophalangeal (MTP) joint motion and flexibility and plantar loads in individuals with high, normal and low arch foot structures. Asymptomatic individuals (n=61), with high, normal and low arches participated in this study. Foot structure was quantified using malleolar valgus index (MVI) and arch height index (AHI). First MTP joint flexibility was measured using a specially constructed jig. Peak pressure under the hallux, 1st and 2nd metatarsals during walking was assessed using a pedobarograph. A one-way ANOVA with Bonferroni-adjusted post hoc comparisons was used to assess between-group differences in MVI, AHI, early and late 1st MTP joint flexibility in sitting and standing, peak dorsiflexion (DF), and peak pressure under the hallux, 1st and 2nd metatarsals. Stepwise linear regression was used to identify predictors of hallucal loading. Significant between-group differences were found in MVI (F(2,56)=15.4, p<0.01), 1st MTP late flexibility in sitting (F(2,57)=3.7, p=0.03), and standing (F(2,57)=3.7, p=0.03). Post hoc comparisons demonstrated that 1st MTP late flexibility in sitting was significantly higher in individuals with low arch compared to high arch structure, and that 1st MTP late flexibility in standing was significantly higher in individuals with low arch compared to normal arch structure. Stepwise regression analysis indicated that MVI and 1st MTP joint early flexibility in sitting explain about 20% of the variance in hallucal peak pressure. Our results provide objective evidence indicating that individuals with low arches show increased 1st MTP joint late flexibility compared to individuals with normal arch structure, and that hindfoot alignment and 1st MTP joint flexibility affect hallucal loading.

STUDY DESIGN: Clinical measurement. OBJECTIVE: To determine the validity and reliability of measures obtained using a custom-made device for assessing ankle dorsiflexion motion and stiffness. BACKGROUND: Limited dorsiflexion has been implicated in the evolution of foot pain in a number of clinical populations. Assessment of ankle dorsiflexion range of motion (ROM) is, therefore, commonly performed as part of a foot and ankle examination. Conventional goniometric assessment methods have demonstrated limited intertester reliability, while alternative methods of measurements are generally more difficult to use. The Iowa ankle range of motion (IAROM) device was designed in an attempt to develop a simple, clinically relevant, and time- and cost-effective tool to measure ankle dorsiflexion range of motion and stiffness. METHODS: Validity and intertester reliability of dorsiflexion range-of-motion measures using the IAROM device were assessed at 10, 15, 20, and 25 Nm of passively applied dorsiflexion torque, with both the knee extended and flexed approximately 20 degrees . Stiffness (change in torque/change in dorsiflexion angle) values were determined using the angular change obtained between the 15- and 25-Nm torque levels. Convergent validity (n = 12) was assessed through comparison of ankle dorsiflexion angles measured simultaneously with the IAROM device and an optoelectronic motion analysis system. Intertester reliability (n = 17) was assessed by 2 testers who took measurements within the same day. RESULTS: Validity testing demonstrated excellent agreement (intraclass correlation coefficient [ICC] values ranging from 0.95 to 0.98). Reliability testing demonstrated good to excellent intertester agreement (ICC values ranging from 0.90 to 0.95). The ICCs for ankle joint dorsiflexion stiffness were .71 and .85 for the knee in an extended and flexed position, respectively. CONCLUSION: The IAROM device provides valid and reliable measurement of ankle dorsiflexion ROM. The IAROM device also allows calculation of stiffness by measuring ROM at multiple torque levels, although the reliability of the measurement is not optimal.

The purpose of the current study was to assess kinematic coupling within the foot in individuals across a range of arch heights. Seventeen subjects participated in this study. Weight-bearing lateral radiographs were used to measure the arch height, defined as angle between the 1st metatarsal and the calcaneus. A kinematic model including the 1st metatarsal, lateral forefoot, calcaneus and tibia was used to assess foot kinematics during walking. Four coupling ratios were calculated: calcaneus frontal to forefoot transverse plane motion (Calcaneal EV/Forefoot AB), calcaneus frontal to transverse plane motion (Calcaneus EV/AB), forefoot sagittal to transverse plane motion (Forefoot DF/AB), and 1st metatarsal sagittal to transverse plane motion (1st Metatarsal DF/AB). Pearson product moment correlations were used to assess the relationship between arch height and coupling ratios. Mean (SD) radiographic arch angles of 129.8 (12.1) degrees with a range from 114 to 153 were noted, underscoring the range of arch heights in this cohort. Arch height explained approximately 3%, 38%, 12% and 1% of the variance in Calcaneal EV/Forefoot AB, Calcaneus EV/AB, Forefoot DF/AB and 1st Metatarsal DF/AB respectively. Calcaneal EV/Forefoot AB, Calcaneus EV/AB, Forefoot DF/AB and 1st Metatarsal DF/AB coupling ratios of 1.84 +/- 0.80, 0.56 +/- 0.35, 0.96 +/- 0.27 and 0.43 +/- 0.21 were noted, consistent with the twisted foot plate model, windlass mechanism and midtarsal locking mechanisms. Arch height had a small and modest relationship with kinematic coupling ratios during walking.

Midfoot arthritis is a common cause of significant pain and disability. Although the medial tarsometatarsal (TMT) joints provide < 7 degrees of sagittal plane motion, the more mobile lateral fourth and fifth TMT joints provide balance and accommodation on uneven ground. These small constrained TMT joints also provide stability and translate the forward propulsion motion of the hindfoot and ankle joint to the forefoot metatarsophalangeal joints from heel rise to toe-off. Posttraumatic degeneration is the primary cause of midfoot arthritis, although primary degeneration and inflammatory conditions can also affect this area. The result is a painful midfoot that can no longer effectively transmit load from the hindfoot to the forefoot. Shoe modifications and orthotic inserts are the mainstay of nonsurgical management. Successful management of midfoot arthritis with orthoses is predicated on achieving adequate joint stabilization while still allowing function. Surgical intervention typically involves arthrodesis of the medial midfoot, although the best treatment of the more mobile lateral column is a subject of debate.