Faculty Bibliography

OBJECTIVE: To assess the effect of a 4-week intervention with a full-length carbon graphite (FL) orthosis on pain and function in patients with midfoot arthritis, and to identify alterations in in vivo foot kinematics accompanying FL use in patients with midfoot arthritis. These results have immediate application for enhancing patient care through effective orthotic recommendations. DESIGN: Experimental laboratory study supplemented by a case series. SETTING: University based clinical research laboratory. PARTICIPANTS: Patients (n=30) with midfoot arthritis and age-, sex-, and body mass index-matched control subjects (n=20). INTERVENTION: Four-week intervention with FL orthoses. MAIN OUTCOME MEASURES: Pain and function were assessed using the Foot Function Index-Revised (FFI-R). In vivo foot kinematics were quantified as peak and total range of calcaneal eversion, forefoot abduction, first metatarsal plantarflexion, and first metatarsophalangeal joint dorsiflexion during walking in 2 conditions: with FL orthoses and with shoes only. A paired t test and repeated-measures analysis of variance were used to assess statistical significance (alpha=.05) of change in FFI-R score and in vivo foot kinematics, respectively. RESULTS: Significant improvements in pain and function, discerned as lower FFI-R scores (P<.001), were noted after the 4-week intervention with FL orthoses. During walking, FL orthosis use resulted in decreased first metatarsophalangeal joint dorsiflexion (P=.024) and first metatarsal plantarflexion range of motion (P=.038), compared with the shoe-only condition. CONCLUSIONS: Orthotic intervention emphasizing a "stiffening" strategy of the first metatarsal and first metatarsophalangeal joint may be valuable in patients with midfoot arthritis and early degenerative changes.

PURPOSE OF REVIEW: The incidence of ankle osteoarthritis has increased in recent years, in part, secondary to vehicular trauma. This review describes conservative and operative intervention strategies along with current research related to the management of ankle osteoarthritis. RECENT FINDINGS: Self-reported physical function in patients with ankle osteoarthritis is equivalent to or worse than that of patients with endstage kidney disease, congestive heart failure, or cervical-spine pain and radiculopathy. Nonoperative-intervention strategies such as assistive devices, orthoses, and viscosupplements are frequently used in this clinical population. However, limited objective data are available examining outcomes following nonoperative intervention. Ankle fusion serves as a standard-surgical treatment for end-stage ankle osteoarthritis. The limitations of ankle fusion include prolonged immobilization, a relatively high risk of nonunion, and adjacent joint arthritis. Increasing evidence supports the safety and efficacy of total-ankle arthroplasty (TAA). Current (third generation) TAA prostheses feature cementless design and ligament preservation with reduced bone resection and improved instrumentation. SUMMARY: Limited objective evidence exists to guide clinical decision-making related to nonoperative choices such as assistive devices, orthoses, and viscosupplements. Outcomes from prospective clinical trials indicate that newer total ankle-arthroplasty designs provide substantial pain relief in patients with end-stage ankle osteoarthritis.

The purpose of our study was to examine dynamic foot function during gait as it relates to plantar loading in individuals with DM (diabetes mellitus and neuropathy) compared to matched control subjects. Foot mobility during gait was examined using a multi-segment kinematic model, and plantar loading was measured using a pedobarograph in subjects with DM (N = 15), control subjects (N = 15). Pearson product moment correlation was used to assess the relationship between variables of interest. Statistical significance and equality of correlations were assessed using approximate tests based on Fisher's Z transformation (alpha = 0.05). In individuals with DM, first metatarsal sagittal plane excursion during gait was negatively associated with pressure time integral under the medial forefoot (r = -0.42 and -0.06, DM and Ctrl, P = 0.02). Similarly, lateral forefoot sagittal plane excursion during gait was negatively associated with pressure time integral under the lateral forefoot (r = -0.56 and -0.11, DM and Ctrl, P = 0.02). Frontal plane excursion of the calcaneus was negatively associated with medial (r = -0.57 and 0.12, DM and Ctrl, P < 0.01) and lateral (r = -0.51 and 0.13, DM and Ctrl, P < 0.01) heel and medial forefoot pressure time integral (r = -0.56 and -0.02, DM and Ctrl, P < 0.01). The key findings of our study indicate that reductions in segmental foot mobility were accompanied by increases in local loading in subjects with DM. Reduction in frontal plane calcaneal mobility during walking serves as an important functional marker of loss of foot flexibility in subjects with DM.

STUDY DESIGN: Experimental laboratory study supplemented by a case series. OBJECTIVES: (1) To assess the effect of a 4-week intervention with a full-length insert on functional outcomes in patients with midfoot arthritis; (2) to examine the effect of the custom molded three-quarter-length (3Q) and full-length (FL) carbon graphite insert on plantar loading in patients with midfoot arthritis. BACKGROUND: Given the coexistence of pain and lower-arched foot alignment in patients with midfoot arthritis, arch-restoring orthotic devices such as the 3Q insert are frequently recommended. However, patients continue to report foot pain despite using the 3Q insert. The FL insert has been proposed as an alternative, but objective data examining its efficacy are lacking. METHODS: Twenty female patients with midfoot arthritis participated in the study. Functional outcomes were assessed using the Foot Function Index-Revised (FFI-R). Plantar loading during walking was measured in the following conditions: shoe only, shoe with 3Q insert, and shoe with FL insert. Repeated-measures analyses of variance with post hoc analyses were used for statistical analysis. RESULTS: FL insert use for 4 weeks resulted in a 12% improvement in total FFI-R score (mean +/- SD before, 35.6 +/- 10.9; after, 31.1 +/- 9.8 [P = .03]). FL insert use resulted in a 20% reduction in medial midfoot average pressure loading (mean +/- SD, 64.8 +/- 20.4 and 51.0 +/- 15.4 kPa, with 3Q and FL insert respectively [P = .015]) and an 8.5% reduction in medial midfoot contact time (mean +/- SD, 84.9% +/- 6.4% and 76.4% +/- 7.1% of stance, with 3Q and FL insert respectively [P<.01]), compared to the 3Q insert. No differences in plantar loading were discerned between the shoe-only and FL conditions. CONCLUSION: Symptomatic improvement in patients with midfoot arthritis treated with a FL insert was accompanied by reduced magnitude and duration of loading under the medial midfoot. These preliminary outcomes suggest that the FL insert may be a viable alternative in the conservative management of patients with midfoot arthritis. LEVEL OF EVIDENCE: Therapy, level 4. J Orthop Sports Phys Ther 2009;39(7):522-531. doi:10.2519/jospt.2009.2900.

The purpose of this study was to compare in vivo segmental foot motion during walking and step descent in patients with midfoot arthritis and asymptomatic control subjects. Segmental foot motion during walking and step descent was assessed using a multi-segment foot model in 30 patients with midfoot arthritis and 20 age, gender and BMI matched controls. Peak and total range of motion (ROM), referenced to subtalar neutral, were examined for each of the following dependent variables: 1st metatarso-phalangeal (MTP1) dorsiflexion, 1st metatarsal (MT1) plantarflexion, ankle dorsiflexion, calcaneal eversion and forefoot abduction. The results showed that, compared to level walking, step descent required greater MTP1 dorsiflexion (p<0.01), MPT1 plantarflexion (p<0.01), ankle dorsiflexion (p<0.01), calcaneus eversion (p=0.03) and forefoot abduction (p=0.01), in all subjects. In addition, step descent also necessitated greater MTP1 dorsiflexion (p<0.01), ankle dorsiflexion (p<0.01) and forefoot abduction (p=0.02) excursion compared to walking. Patients with midfoot arthritis responded differently to the step task compared to control subjects in terms of MT1 and calcaneus eversion excursion. During walking, patients with midfoot arthritis showed significantly less MT1 plantarflexion excursion compared to control subjects (p=0.03). However, during step descent, both groups showed similar MT1 plantarflexion excursion. During walking, patients with midfoot arthritis showed similar calcaneus eversion excursion compared to control subjects. However, during step descent, patients with midfoot arthritis showed significantly greater calcaneus eversion excursion compared to control subjects (p=0.03). Independently or in combination, these motions may contribute to articular stress and consequently to symptoms in patients with midfoot arthritis.

Arthritis of the midtarsal and tarsometatarsal joints (midfoot) has emerged as a challenging problem because of its high potential for chronic foot pain and functional disability. Although the incidence of patients presenting with midfoot arthritis is increasing at an alarming rate, guidelines for clinical decision making are lacking in the literature. The primary aim of treatment is to afford pain relief by enhancing midfoot stability and modifying loads sustained at the inflamed joints. These treatment goals are attempted initially through conservative management such as orthoses followed by surgery. This manuscript discusses strategies for conservative management and details the operative techniques for tarsometatarsal fusion. In addition, outcomes after intervention are presented. © 2008 Lippincott Williams & Wilkins, Inc.

BACKGROUND: Impairment in intrinsic foot mobility has been identified as an important potential contributor to altered foot function in individuals with diabetes mellitus and neuropathy, however the role of limited foot mobility in gait remains poorly understood. The purpose of our study was to examine segmental foot mobility during gait in subjects with and without diabetes and neuropathy. METHODS: Segmental foot mobility during gait was examined using a multi-segment kinematic foot model in subjects with diabetes (n=15) and non-diabetic control subjects (n=15). FINDINGS: Subjects with diabetes showed reduced frontal as well as sagittal plane excursion of the calcaneus relative to the tibia. Decreased excursion of the first metatarsal relative to the calcaneus in the frontal as well as transverse plane was noted in subjects with diabetes. INTERPRETATION: Our findings agree with traditional understanding of foot mechanics and shed new light on patterns and magnitude of motion during gait. Calcaneal pronation, noted in early stance in both groups, was reduced in subjects with diabetes and may have important consequences on joints proximal as well as distal to it. Subjects with diabetes showed reduced foot 'splay' in early stance, indicated by first metatarsal and forefoot eversion. At terminal stance, decreases in calcaneal plantarflexion, first metatarsal and forefoot supination were noted in subjects with diabetes, suggesting that less supination is required in subjects with diabetes to create a rigid lever. In subjects with diabetes, a greater proportion of midfoot stability may be derived from modified/stiffer soft tissue such as the plantar fascia.

INTRODUCTION: The purpose of our study was to examine the relationship between ankle dorsiflexion (DF) range of motion (ROM) and stiffness measured at rest (passively) and plantar loading during gait in individuals with and without diabetes mellitus (DM) and sensory neuropathy. Specifically, we sought to address three questions for this at-risk patient population: (1) Does peak passive DF ROM predict ankle DF ROM used during gait? (2) Does passive ankle stiffness predict ankle stiffness used during gait? (3) Are any of the passive or gait-related ankle measures associated with plantar loading? METHODS: Ten subjects with DM and 10 age and gender matched non-diabetic control subjects participated in this study. Passive ankle DF ROM and stiffness were measured with the Iowa Ankle ROM device. Kinematic, kinetic and plantar pressure data were collected as subjects walked at 0.89 m/s. RESULTS: We found that subjects with DM have reduced passive ankle DF ROM and increased stiffness compared to non-diabetic control subjects, however, subjects with DM demonstrated ankle motion, stiffness and plantar pressures, similar to control subjects, while walking at the identical speed, 0.89 m/s (2 mph). These data indicate that clinical measures of heel cord tightness and stiffness do not represent ankle motion or stiffness utilized during gait. Our findings suggest that subjects with DM utilize strategies such as shortening their stride length and reducing their push-off power to modulate plantar loading.

BACKGROUND:The purpose of our study was to compare ankle range of motion and stiffness in individuals with and without diabetes mellitus using a reliable and valid technique and to document the effect of knee flexion and severity of pathology on ankle range of motion and stiffness. METHODS:Twenty-five individuals with diabetes mellitus and 64 nondiabetic individuals, similar in age and gender profile, participated in this study. RESULTS:Results revealed that individuals with diabetes mellitus had both significantly lower peak dorsiflexion range of motion (5.1 and 11.5 degrees, p < 0.001) and higher passive ankle stiffness (0.016 and 0.008 Nm/kg/degree, p < 0.01) than non-diabetic individuals. In individuals with diabetes mellitus, a positive relationship between glycemic control and duration of diabetes mellitus and ankle stiffness ((r(2) = 0.48 and 0.24 respectively, p < 0.01 for both) was found. CONCLUSION/CONCLUSIONS:While decreased range of motion and increased stiffness in the diabetes mellitus population seem clinically intuitive, as far as we know this is the first study to confirm the concurrent existence of both these findings in the plantarflexors in individuals with diabetes mellitus. We applied a reliable and valid technique, one that allowed control of confounding factors such as knee flexion position and differences in determination of end range of motion, and documented a mean 41% loss in dorsiflexion excursion. Changes in the muscle, stemming from underlying pathology, are hypothesized to account for a significant part of the lost range of motion. Changes in ankle range of motion and stiffness may have important implications in plantar loading and ulcer formation.

Ground reaction forces (GRF) are associated with bone hypertrophy; therefore, they are important to understanding physical activity's role in children's bone health. In this study, we examined the ability of accelerometry to predict vertical GRF in 40 children (mean age 8.6 yr) during slow walking, brisk walking, running, and jumping. Correlation coefficients between accelerometry-derived movement counts and GRF were moderate to high and significant during walking and running, but not during jumping. Given a large proportion of children's daily physical activity involves ambulation, accelerometry should be useful as a research method in bone-related research. However, this method underestimates GRF during jumping, an important physical activity for bone modeling and remodeling.