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Fine-wire electromyography (EMG) is a traditional laboratory technique to estimate muscle activity of the small foot muscles, however, recordings have not been reported from extensor hallucis brevis (EHB). As an extensor of the great toe, EHB is an important muscle when studying physiological changes associated with foot pathologies such as hallux valgus. The purpose of this study was to develop an ultrasound-guided fine-wire EMG protocol to record EHB muscle activity and report normative EMG profiles of healthy young adults during locomotion. Sixteen asymptomatic young adults completed 20 walking trials at a self-selected velocity. Ensemble averages were calculated from the time normalized linear envelopes and represented from 0% to 100% of the single stance phase of gait. EHB muscle bursts were observed between 0% and 20% of the stance phase of gait in all participants. A second burst of EMG was observed between 80% and 100% of stance in 50% of the participants. This study introduces a novel ultrasound-guided EMG protocol and normative data from EHB recordings suggest a synergistic role to anterior compartment musculature at contact. These results provide preliminary insights into understanding the functional role of EHB and may help elucidate the biomechanical factors exacerbating the progression of hallux pathologies. [ABSTRACT FROM AUTHOR]

Introduction: The biomechanical factors influencing metatarsalgia etiology have been well documented; however, patient characteristics of individuals suffering from this condition and the effectiveness of foot orthosis therapy remain unknown. Objectives: The objectives of this study were 1) to characterize the metatarsalgia profile of patients seeking treatment in a footwear and orthotic clinic, and 2) to explore the association between comfort and pain in patients with metatarsalgia who were treated with foot orthosis intervention. Study Design: This study is a retrospective chart review. Methods: Metatarsalgia assessment and follow-up data (case group n = 2137) were extracted from a research database (control group n = 82,822) from patients visiting a private foot care clinic. A clinical assessment was performed by a Canadian-certified pedorthist, and footwear recommendations and bilateral custom foot orthoses were provided to all patients. Feet were casted using a three-dimensional volumetric laser scanner. Orthoses (80% of cases) were manufactured from a direct mill polypropylene shell; additional rearfoot, forefoot postings, and/or metatarsal support was added according to the patient’s personalized treatment plan. Results: Eighty-one percent (81%) of metatarsalgia patients reported symptom improvement following custom orthoses treatment. The average pain reduction from the orthotic intervention was 58.55%. The average self-reported comfort scores were 7.7 ± 2.2/10 at follow-up. Compared with our control group, patients with metatarsalgia were more frequently self-identified as females, over 51 years of age, and the condition was observed in a higher prevalence of high cavus feet. Conclusions: Our results suggest that a pes cavus foot posture is a biomechanical risk factor to the development of metatarsalgia. Custom foot orthoses that are manufactured according to a patient’s personalized treatment plan are an effective conservative treatment option for pain reduction in patients suffering from metatarsalgia. [ABSTRACT FROM AUTHOR]

The purpose of this study was to facilitate sensory feedback, with textured foot orthotics, to evaluate dynamic stability and turning behavior in Parkinson's disease individuals. Seven participants with a diagnosis of idiopathic Parkinson's disease, aged 55-80 years old, participated in this study. Participants completed three testing sessions; baseline, 4 weeks post-baseline, and 5 weeks post-baseline. Three experimental conditions were tested: footwear only (F), footwear + non-textured orthotic (FO), and footwear + textured orthotic (FOT). Kinematic, kinetic, and video data were collected during the steps preceding a turn task. Variables of interest included dynamic stability (maximum mediolateral (ML), minimum ML, and ML range of the center of mass (COM)-base of support (BOS) relationship) and turning performance (gait velocity and step count). There was a statistically significant increase in maximum ML COM-BOS distance (week 4 [0.1298 m ± 0.054] compared to week 0 [0.1069 m ± 0.050] p = .0076), and a significant decrease in step count (week 0-F [5.52 steps ± 1.08] to week 0-FO [5.23 steps ± 0.87] p = .0296) and (week 4-FO [5.24 steps ± 1.31] to week 4-FOT [4.67 steps ± 0.76] p = .0004). Textured foot orthotics modified dynamic stability and turning performance in Parkinson's disease individuals completing a 180° degree turn. These preliminary results support this potential treatment option for rehabilitation professionals treating Parkinson's disease. [ABSTRACT FROM AUTHOR]