The Feasibility of Using Augmented Auditory Feedback From a Pressure Detecting Insole to Reduce the Knee Adduction Moment: A Proof of Concept Study.

The objective of this work was to conduct a proof of concept study utilizing auditory feedback from a pressure-detecting shoe insole to shift plantar pressure medially in order to reduce the knee adduction moment (KAM). When compared with normal walking, 32 healthy subjects significantly reduced their peak KAM using feedback (p < 0.001). When compared with medial thrust gait, an established gait modification, walking with pressure-based feedback was equally effective at reducing the peak KAM, yet it successfully mitigated other potentially detrimental gait measures such as the peak knee flexion moment (KFM), knee internal rotation moment (KIrM), and a reduction in speed.

Improvement in knee loading after use of specialized footwear for knee osteoarthritis: results of a six-month pilot investigation.

OBJECTIVE: Biomechanical interventions for knee osteoarthritis (OA) aim to improve pain and retard disease progression by decreasing knee loading. This study was undertaken to evaluate the effects of 6 months of use of flat, flexible footwear (the mobility shoe) on knee loading in OA. METHODS: Subjects with knee OA underwent baseline gait analyses under conditions of walking in their own shoes, walking in mobility shoes, and walking barefoot. Thereafter, subjects wore the mobility shoes at least 6 hours per day for 6 days per week. Gait evaluations were repeated at 6, 12, and 24 weeks. An intent-to-treat analysis was performed to assess the longitudinal effects on knee loading with the shoe intervention. RESULTS: Compared to knee loading at baseline with the participants' own shoes, there was an 18% reduction in the knee adduction moment (KAM) by 24 weeks with the mobility shoes (P < 0.001) and no significant differences in the KAM by 24 weeks between mobility shoe and barefoot walking (P = 0.192). Over the 6 months of followup, participants also experienced an 11% reduction in the KAM when walking in their own shoes (P = 0.002) and a 10% reduction in the KAM when walking barefoot (P = 0.002 for the whole followup), as compared to these values at baseline under the same conditions. CONCLUSION: This study suggests that use of flat, flexible footwear results in significant reductions in knee loading in subjects with OA. By 24 weeks, there is evidence of a gait adaptation with sustained load reduction even when the mobility shoes are removed, suggesting that footwear may serve as a biomechanical training device to achieve beneficial alterations in gait mechanics for knee OA.

Asymmetric loading and bone mineral density at the asymptomatic knees of patients with unilateral hip osteoarthritis.

OBJECTIVE: In patients with unilateral end-stage hip osteoarthritis (OA), the contralateral knee is known to be at greater risk for end-stage knee OA compared to the ipsilateral (i.e., same-side) knee. The contralateral knee is known to have increased dynamic joint loads compared to the ipsilateral knee. The present study was undertaken to examine patients who had unilateral hip OA but who did not have symptoms of knee OA, in order to detect early asymmetries in knee loading. METHODS: Data on 62 patients with unilateral hip OA were evaluated. Patients underwent gait analyses of dynamic knee loads as well as dual x-ray absorptiometry for determination of bone mineral density (BMD) in both knees. Differences between knees were compared. RESULTS: Peak dynamic knee loads were significantly higher at the contralateral knee compared to the ipsilateral knee (mean ± SD 2.46 ± 0.71 percent of body weight × height versus 2.23 ± 0.81 percent of body weight × height; P = 0.029). Similarly, medial compartment tibial BMD was significantly higher in the contralateral knee compared to the ipsilateral knee (mean ± SD 0.897 ± 0.208 gm/cm(2) versus 0.854 ± 0.206 gm/cm(2); P = 0.033). Interestingly, there was a direct correlation between the contralateral:ipsilateral dynamic knee load and contralateral:ipsilateral medial compartment tibial BMD (ρ = 0.287, P = 0.036). CONCLUSION: The risk of developing progressive symptomatic OA in contralateral knees is higher compared to the risk in ipsilateral knees in patients with unilateral hip OA. The present study demonstrates that loading and structural asymmetries appear early in the disease course, while the knees are still asymptomatic. These early biomechanical asymmetries may have corresponding long-term consequences, providing further evidence for the potential role of loading in OA onset and progression.

An investigation of alternating group dissections in medical gross anatomy.

BACKGROUND: Reduction in contact hours has led to the use of more efficient teaching approaches in medical education, yet the efficacy of such approaches is often not fully investigated. PURPOSE: This work provides a detailed analysis of alternating group dissections with peer-teaching in Medical Anatomy (MA). METHODS: MA I and II percentages of the alternating (ALT) and nonalternating (NALT) groups were compared, scores of ALT subgroups (A and B) were compared, and subgroup performance on practical exam questions was compared. RESULTS: MA I and MA II percentages indicated no significant difference in median scores (pMAI=0.581, pMAII=0.223) between ALT and NALT. Subgroup analysis and assessment of question types showed that student performance and ability to identify a structure were not dependent on dissection group assignment. CONCLUSION: Alternating dissections offered students more unscheduled time for independent learning activities, such as studying or shadowing preceptors, and reduced student-to-cadaver and student-to-faculty ratios by 50%. Alternating dissections with peer teaching were not detrimental to student performance.

Differences in preferred walking speeds in a gait laboratory compared with the real world after total hip replacement.

OBJECTIVE: To evaluate the relation between walking speeds measured in a gait laboratory and those measured in real-world settings (habitual speed) in subjects with total hip replacements (THRs) and control subjects. The secondary objective is to determine whether the relationship between gait laboratory and habitual speeds was affected by recovery time or related to clinical indices. DESIGN: Cohort study. SETTING: Academic medical center. PARTICIPANTS: Experimental subjects (n=26) evaluated 3 weeks and 12 months after THR and control subjects (n=24). INTERVENTIONS: None. MAIN OUTCOME MEASURES: Walking speed measured in the gait laboratory, walking speed measured in the field by using activity monitors, Harris Hip Score (HHS), and the Western Ontario and McMaster Osteoarthritis Index (WOMAC). RESULTS: Laboratory speeds were significantly faster than habitual speeds in all groups (P<.001), but the 2 correlated significantly. The laboratory versus habitual-speed difference was unaffected by recovery time within the THR group (P=.180) but was larger for control subjects (.32+/-.21m/s) than for THR subjects (.19+/-.15m/s 1 year after surgery). Habitual speed significantly correlated with total WOMAC scores and with WOMAC stiffness and function subscores 3 weeks after THR. The HHS weakly correlated with 3-week laboratory speed. No speed and clinical correlations were seen 1 year after THR. CONCLUSIONS: Although subjects may exaggerate walking speeds in laboratory settings, laboratory-based data accurately reflect real-world activity. Setting affected speeds most in the control group. It is important to consider potential discrepancies between speeds walked in a laboratory versus in the real world when interpreting gait studies comparing 2 or more populations. Finally, analysis of these data suggests that clinical indices may more accurately reflect biomechanical function during early recovery after THR than after full recovery.

Bridging the transfer gap: laboratory exercise combines clinical exposure and anatomy review.

OBJECTIVES: One of the goals of medical education is to bridge the gap between basic science and clinical practice. Students acquire basic science knowledge during their pre-clinical years, yet have limited opportunities to apply this knowledge clinically. This hands-on laboratory exercise was designed to facilitate a review of anatomy in the context of select clinical procedures, highlighting the application of anatomical concepts in clinical practice. METHODS: In 2008, Year 2 medical students participated in a clinical procedures laboratory taught by senior residents and attending physicians. Before participating, all students completed anatomy and clinical pre-tests and received syllabi detailing the select procedures and the anatomy pertinent to each. Students were organised into experimental (EG, n = 48) and control (CG, n = 17) groups. The EG observed and practised five procedures on cadavers and the CG participated in a traditional anatomy review laboratory with no procedural demonstrations or practice. Anatomy and clinical post-tests were administered to both groups following the 3-hour interventions. Surveys and focus sessions were used to assess student opinions. RESULTS: Scores on the anatomy pre- and post-tests were compared and were found to have significantly increased (P

Using generalizability analysis to estimate parameters for anatomy assessments: A multi-institutional study.

With integrated curricula and multidisciplinary assessments becoming more prevalent in medical education, there is a continued need for educational research to explore the advantages, consequences, and challenges of integration practices. This retrospective analysis investigated the number of items needed to reliably assess anatomical knowledge in the context of gross anatomy and histology. A generalizability analysis was conducted on gross anatomy and histology written and practical examination items that were administered in a discipline-based format at Indiana University School of Medicine and in an integrated fashion at the University of Alabama School of Medicine and Rush University Medical College. Examination items were analyzed using a partially nested design s×(i:o) in which items were nested within occasions (i:o) and crossed with students (s). A reliability standard of 0.80 was used to determine the minimum number of items needed across examinations (occasions) to make reliable and informed decisions about students' competence in anatomical knowledge. Decision study plots are presented to demonstrate how the number of items per examination influences the reliability of each administered assessment. Using the example of a curriculum that assesses gross anatomy knowledge over five summative written and practical examinations, the results of the decision study estimated that 30 and 25 items would be needed on each written and practical examination to reach a reliability of 0.80, respectively. This study is particularly relevant to educators who may question whether the amount of anatomy content assessed in multidisciplinary evaluations is sufficient for making judgments about the anatomical aptitude of students. Anat Sci Educ 10: 109-119. © 2016 American Association of Anatomists.

A reduction in the knee adduction moment with medial thrust gait is associated with a medial shift in center of plantar pressure.

The knee adduction moment (KAM) is an established marker of compartmental load distribution across the tibiofemoral joint. Research suggests a link between the magnitude of the KAM and center of plantar pressure (COP) thus alterations in the two may be related. The objective of this study was to investigate whether the COP predictably shifts when the KAM is reduced through a gait adaptation. Twenty healthy adults underwent gait analysis walking with their normal gait pattern and with medial thrust gait, a gait adaptation known to significantly reduce the KAM. Simultaneous COP and 3-D kinetics were acquired to allow for a comparison of the change in COP to the change in the KAM. The COP was quantified by determining a customized medial-lateral pressure index (MLPI) which compares the COP tracing line during the first and second halves of stance to the longitudinal axis of the foot. Linear regressions assessing the association between the changes in KAM and MLPI indicated that 48.3% (p=0.001) of the variation in MLPI during the first half of stance can be explained by the KAM during the same period. A trend was observed between the association between the KAM and MLPI during the second half of stance (R(2)=0.16, p=0.080). Backwards elimination regression analysis was used to explore whether simultaneous consideration of the KAM and other potential confounding factors such as sagittal plane knee moments and speed explained variance in the MLPI during the first half of stance. Only the KAM exhibited explanatory power (ß=0.695, p=0.001). During medial thrust gait, a reduction in the KAM was associated with a medial shift in the MLPI, and an increase in the KAM was associated with a lateral shift in the MLPI, especially in the first half of the stance phase. Together, these results demonstrate an inherent link between foot pressure and the KAM during medial thrust gait, and suggest that manipulating foot pressure may be a biomechanical mechanism for an intervention designed to improve loading conditions at the knee.

Activity Levels in Healthy Older Adults: Implications for Joint Arthroplasty.

This work evaluated activity levels in a group of healthy older adults to establish a target activity level for adults of similar age after total joint arthroplasty (TJA).With the decreasing age of TJA patients, it is essential to have a reference for activity level in younger patients as activity level affects quality of life and implant design. 54 asymptomatic, healthy older adults with no clinical evidence of lower extremity OA participated. The main outcome measure, average daily step count, was measured using an accelerometer-based activity monitor. On average the group took 8813 ± 3611 steps per day, approximately 4000 more steps per day than has been previously reported in patients following total joint arthroplasty. The present work provides a reference for activity after joint arthroplasty which is relevant given the projected number of people under the age of 65 who will undergo joint arthroplasty in the coming years.

Relationship between pain and medial knee joint loading in mild radiographic knee osteoarthritis.

OBJECTIVE: The relationship between knee pain and radiographic evidence of knee osteoarthritis (OA) is notoriously imperfect. In particular, conditions that distinguish individuals with symptoms from those with comparable radiographic involvement who remain asymptomatic are unclear. We investigated dynamic loading across the knee in individuals with mild radiographic OA who were distinguished by the presence or absence of knee pain. METHODS: Subjects were recruited into 3 groups: symptomatic with a Kellgren/Lawrence (K/L) grade of 2 (n = 52), asymptomatic with a K/L grade of 2 (n = 19), and asymptomatic with a K/L grade of 0 or 1 (n = 37), the latter representing a normal comparator group. Dynamic knee loading was assessed with gait analysis, and both the peak external knee adduction moment and the knee adduction angular impulse were determined. RESULTS: Peak knee adduction moment and knee adduction angular impulse were 19% and 30% higher, respectively, in symptomatic K/L grade 2 individuals than in asymptomatic individuals with the same radiographic grade (P < 0.05). Conversely, the asymptomatic K/L grade 2 group did not differ from the K/L grade 0-1 normal comparator group (P = 1.00). CONCLUSION: Among individuals with mild radiographic knee OA (K/L grade 2), those who are symptomatic have significantly higher medial compartment loads than those who are asymptomatic, whereas those who are asymptomatic do not differ from normal controls (asymptomatic K/L grade 0 or 1). These findings suggest a biomechanical component to the distinction between asymptomatic and symptomatic radiographic OA, which may be pathophysiologically important.

Knee joint loading differs in individuals with mild compared with moderate medial knee osteoarthritis.

OBJECTIVE: To compare the knee joint loading patterns in individuals with differing radiographic grades of knee osteoarthritis (OA) for characterization of the mechanical implications of different structural states, and to compare the knee adduction angular impulse, a measure of gait complementary to the commonly used peak knee adduction moment. METHODS: Asymptomatic subjects (those without knee OA) having a Kellgren/Lawrence (K/L) radiographic severity grade of 0 or 1 (n = 28) and subjects with symptomatic knee OA having K/L grades of 2 (n = 66) or 3 (n = 23) were recruited. Gait analysis was used to calculate the peak external knee adduction moment and the external knee adduction angular impulse for the whole stance and for the 4 subdivisions of stance. RESULTS: Both the peak knee adduction moment and the knee adduction angular impulse increased with K/L radiographic grade (P < 0.05). However, only the knee adduction angular impulse differed between subjects with moderate (grade 3) and those with mild (grade 2) radiographic knee OA (P < 0.05). CONCLUSION: The differences between mild and moderate symptomatic radiographic knee OA are not only structural but also functional, based on the magnitude of load in the medial knee joint. Moreover, knee adduction angular impulse provides additional information beyond that available from the peak knee adduction moment, and may therefore be an important gait parameter to include in OA research. These findings are important for our understanding of the pathophysiologic mechanisms of OA.