Jody L. Riskowski

Arthritis, foot pain and shoe wear: current musculoskeletal research on feet.

Purpose of reviewBoth arthritis and foot pain are major public health problems. Approximately 24% of adults have foot ailments, and the prevalence increases with age. Foot pain, particularly related to shoes, footwear and rheumatic disorders, may be an important modifiable factor. Surprisingly, this topic has received little attention in the rheumatology community. Recent findingsDespite the major focus of structure and alignment in arthritis, remarkably little work has focused on the foot and nonsurgical foot interventions that might affect lower extremity joint alignment, structure and pain in rheumatic diseases. Emerging research suggests that there may be a significant role for foot orthotics and footwear in the treatment of rheumatoid arthritis and osteoarthritis of the hip, knee and foot. This review highlights the current understanding on the topic of foot orthotics and footwear in adults with rheumatic diseases. SummaryBiomechanical evidence indicates that foot orthotics and specialized footwear may change muscle activation and gait patterns to reduce joint loading. Emerging evidence suggests that orthotics, specific shoe types and footwear interventions may provide an effective nonsurgical intervention in rheumatic diseases. Yet good data are sparse, and it is premature to recommend guidelines. As there are a limited number of studies that underpin the foots role in arthritis cause and progression, clinical trials and prospective studies are of utmost importance to unravel the links between foot pain, foot conditions and interventions that lessen the impact of rheumatic diseases.

Associations of Socioeconomic Position and Pain Prevalence in the United States: Findings from the National Health and Nutrition Examination Survey

BACKGROUND Pain is a significant burden within the U.S. adult population, but little is known regarding epidemiology of pain, particularly with respect to race, ethnicity, and socioeconomic position (SEP). OBJECTIVE The purpose of this study was to describe and evaluate prevalence and distribution of pain in the United States. METHODS With data from the population-based 2003-2004 National Health and Nutrition Examination Survey, prevalence of acute (<3 months) and chronic (≥ 3 months) pain was evaluated, including subgroup analyses of race, ethnicity, and SEP, with SEP defined by the poverty-to-income ratio, a ratio derived from the federal poverty level, accounting for household income and number of household members. RESULTS Prevalence of acute pain was 12.2% (95% confidence interval: 11.2-13.3%). Non-Hispanic black as well as Hispanic and Mexican-American individuals had higher rates of acute pain than non-Hispanic white people, and a higher prevalence was noted in those with higher SEP. Chronic pain prevalence was 15.6% (13.4-17.7%), with non-Hispanic white people having a higher prevalence than those in other racial and ethnic groups. CONCLUSION Trends of chronic pain by SEP were opposite of acute pain as those in the highest SEP group tended to have less chronic pain than those in lower SEP groups. These findings suggest that SEP, in addition to race and ethnicity, may play a role in the development of pain as well as its treatment and management.

Foot Disorders, Foot Posture, and Foot Function: The Framingham Foot Study

Introduction Foot disorders are common among older adults and may lead to outcomes such as falls and functional limitation. However, the associations of foot posture and foot function to specific foot disorders at the population level remain poorly understood. The purpose of this study was to assess the relation between specific foot disorders, foot posture, and foot function. Methods Participants were from the population-based Framingham Foot Study. Quintiles of the modified arch index and center of pressure excursion index from plantar pressure scans were used to create foot posture and function subgroups. Adjusted odds ratios of having each specific disorder were calculated for foot posture and function subgroups relative to a referent 3 quintiles. Results Pes planus foot posture was associated with increased odds of hammer toes and overlapping toes. Cavus foot posture was not associated with the foot disorders evaluated. Odds of having hallux valgus and overlapping toes were significantly increased in those with pronated foot function, while odds of hallux valgus and hallux rigidus were significantly decreased in those with supinated function. Conclusions Foot posture and foot function were associated with the presence of specific foot disorders.

Foot posture, foot function and low back pain: the Framingham Foot Study

OBJECTIVE Abnormal foot posture and function have been proposed as possible risk factors for low back pain, but this has not been examined in detail. The objective of this study was to explore the associations of foot posture and foot function with low back pain in 1930 members of the Framingham Study (2002-05). METHODS Low back pain, aching or stiffness on most days was documented on a body chart. Foot posture was categorized as normal, planus or cavus using static weight-bearing measurements of the arch index. Foot function was categorized as normal, pronated or supinated using the centre of pressure excursion index derived from dynamic foot pressure measurements. Sex-specific multivariate logistic regression models were used to examine the associations of foot posture, foot function and asymmetry with low back pain, adjusting for confounding variables. RESULTS Foot posture showed no association with low back pain. However, pronated foot function was associated with low back pain in women [odds ratio (OR) = 1.51, 95% CI 1.1, 2.07, P = 0.011] and this remained significant after adjusting for age, weight, smoking and depressive symptoms (OR = 1.48, 95% CI 1.07, 2.05, P = 0.018). CONCLUSION These findings suggest that pronated foot function may contribute to low back symptoms in women. Interventions that modify foot function, such as orthoses, may therefore have a role in the prevention and treatment of low back pain.

Associations of foot posture and function to lower extremity pain: results from a population-based foot study.

Studies have implicated foot posture and foot function as risk factors for lower extremity pain. Empirical population‐based evidence for this assertion is lacking; therefore, the purpose of this study was to evaluate cross‐sectional associations of foot posture and foot function to lower extremity joint pain in a population‐based study of adults.

Functional Foot Symmetry and Its Relation to Lower Extremity Physical Performance in Older Adults: The Framingham Foot Study

BACKGROUND While many studies use gait symmetry as a marker of healthy gait, the evidence that gait symmetry exists is limited. Because gait symmetry is thought to arise through laterality (i.e., limb preference) and affects gait retraining efforts, it is important to understand if symmetry exists during gait in older adults. Therefore, the purpose of this study was to evaluate foot and gait symmetry in the population-based Framingham Foot Study as well as to determine the effects of vertical force symmetry on physical performance measures. METHODS Members of the Framingham Foot Study were included in this analysis (N=1333). Foot function and force data were collected using the Tekscan Matscan during self-selected gait, with symmetry evaluated using the symmetry index. The short physical performance battery (SPPB) measures of balance, chair stands and gait speed assessed lower extremity physical function. Participants were evaluated using quartiles of gait speed and foot symmetry to determine the effects of symmetry on lower extremity physical function. RESULTS Individuals with faster gait speed displayed greater foot function asymmetry; individuals with -3.0% to -9.5% asymmetry in foot function performed better on the short physical performance battery (SPPB). Further, with aging, the degree of asymmetry was reduced. CONCLUSIONS While this research suggests that a moderate degree of foot asymmetry is associated with better lower extremity function, the causes of vertical force asymmetry are unknown. Future studies should evaluate the causes of foot asymmetry and should track the changes in symmetry that occur with aging.

Hallux valgus and plantar pressure loading: the Framingham foot study

BackgroundHallux valgus (HV), a common structural foot deformity, can cause foot pain and lead to limited mobility. The purpose of this study was to evaluate differences in plantar pressure and force during gait by HV status in a large population-based cohort of men and women.MethodsA trained examiner performed a validated physical examination on participants’ feet and recorded the presence of hallux valgus and other specific foot disorders. Each foot was classified into one of four mutually exclusive groups based on the foot examination. Foot groups were: (i) HV only, (ii) HV and at least one additional foot disorder (FD), (iii) no HV but at least one other FD, and (iv) neither HV nor FD (referent). Biomechanical data for both feet were collected using Tekscan Matscan. Foot posture during quiet standing, using modified arch index (MAI), and foot function during gait, using center of pressure excursion index (CPEI), were calculated per foot. Further, walking scans were masked into eight sub-regions using Novel Automask, and peak pressure and maximum force exerted in each region were calculated.ResultsThere were 3205 participants, contributing 6393 feet with complete foot exam data and valid biomechanical measurements. Participants with HV had lower hallucal loading and higher forces at lesser toes as well as higher MAI and lower CPEI values compared to the referent. Participants with HV and other FDs were also noted to have aberrant rearfoot forces and pressures.ConclusionsThese results suggest that HV alters foot loading patterns and pressure profiles. Future work should investigate how these changes affect the risk of other foot and lower extremity ailments.

Association of Planus Foot Posture and Pronated Foot Function With Foot Pain: The Framingham Foot Study

To examine the associations of foot posture and foot function to foot pain.

Factors affecting center of pressure in older adults: the Framingham Foot Study

BackgroundAlthough aberrant foot movement during gait has been associated with adverse outcomes in the lower extremities in clinical patients, few studies have analyzed population differences in foot function. The purpose of this study was to assess demographic differences in foot function in a large population-based study of community-dwelling adults.MethodsParticipants in this study were from the Framingham Foot Study. Walking data were collected from both feet using a Tekscan Matscan pressure mat. Foot function was characterized using the center of pressure excursion index (CPEI). T-tests were used to assess differences between population subsets based on sex, and in men and women separately, age, body mass index (BMI), physical activity and in women, past high heel use.ResultsThere were 2111 participants included in this analysis. Significant differences in CPEI were noted by sex (p< 0.0001), by age in women (p = 0.04), and by past high heel use in women (p = 0.04).ConclusionsFoot function during gait was affected by sex, as well as by age and shoe-wear in women, but not by BMI or physical activity. Future work will evaluate possible relations between CPEI and outcomes such as falls, sarcopenia, and lower extremity function.

Teaching undergraduate biomechanics with Just-in-Time Teaching

Biomechanics education is a vital component of kinesiology, sports medicine, and physical education, as well as for many biomedical engineering and bioengineering undergraduate programmes. Little research exists regarding effective teaching strategies for biomechanics. However, prior work suggests that student learning in undergraduate physics courses has been aided by using the Just-in-Time Teaching (JiTT). As physics understanding plays a role in biomechanics understanding, the purpose of study was to evaluate the use of a JiTT framework in an undergraduate biomechanics course. This two-year action-based research study evaluated three JiTT frameworks: (1) no JiTT; (2) mathematics-based JiTT; and (3) concept-based JiTT. A pre- and post-course assessment of student learning used the biomechanics concept inventory and a biomechanics concept map. A general linear model assessed differences between the course assessments by JiTT framework in order to evaluate learning and teaching effectiveness. The results indicated significantly higher learning gains and better conceptual understanding in a concept-based JiTT course, relative to a mathematics-based JiTT or no JiTT course structure. These results suggest that a course structure involving concept-based questions using a JiTT strategy may be an effective method for engaging undergraduate students and promoting learning in biomechanics courses.