Use of computed tomography to identify muscle quality subgroups, spatial mapping, and preliminary relationships to function in those with diabetic peripheral neuropathy.

Background: Decreased muscle volume and increased muscle-associated adipose tissue (MAAT, sum of intra and inter-muscular adipose tissue) of the foot intrinsic muscle compartment are associated with deformity, decreased function, and increased risk of ulceration and amputation in those with diabetic peripheral neuropathy (DPN).

Research Question: What is the muscle quality (normal, abnormal muscle, and adipose volumes) of the DPN foot intrinsic compartment, how does it change over time, and is muscle quality related to gait and foot function?

Methods: Computed tomography was performed on the intrinsic foot muscle compartment of 45 subjects with DPN (mean age: 67.2 ± 6.

Achilles tendon assessment on quantitative MRI: Sources of variability and relationships to tendinopathy.

Quantitative MRI (qMRI) measures are useful in assessing musculoskeletal tissues, but application to tendon has been limited. The purposes of this study were to optimize, identify sources of variability, and establish reproducibility of qMRI to assess Achilles tendon. Additionally, preliminarily estimates of effect of tendon pathology on qMRI metrics and structure-function relationships between qMRI measures and ankle performance were examined.

Quantitative Assessment of Peripheral Oxidative Metabolism With a New Dynamic H MRI Technique: A Pilot Study in People With and Without Diabetes Mellitus.

Background: Type 2 diabetes mellitus (T2DM) is linked to impaired mitochondrial function. Chemical exchange saturation transfer (CEST) magnetic resonance imaging (MRI) is a gadolinium-contrast-free H method to assess mitochondrial function by measuring low-concentration metabolites. A CEST MRI-based technique may serve as a non-invasive proxy for assessing mitochondrial health.

Rate of tarsal and metatarsal bone mineral density change in adults with diabetes mellitus and peripheral neuropathy: a longitudinal study.

Background: In people with diabetes (DM) and peripheral neuropathy (PN), loss of bone mineral density (BMD) in the tarsals and metatarsals contribute to foot complications; however, changes in BMD of the calcaneal bone is most commonly reported. This study reports rate of change in BMD of all the individual bones in the foot, in participants with DM and PN. Our aim was to investigate whether the rate of BMD change is similar across all the bones of the foot.

Regional skeletal muscle perfusion distribution in diabetic feet may differentiate short-term healed foot ulcers from non-healed ulcers.

Objectives: The purpose of this study was to leverage a magnetic resonance imaging (MRI) approach to characterize foot perfusion distribution in patients with diabetes, with or without foot ulcers, and determine the ability of the regional perfusion measurements to identify ulcer-healing status.

Methods: Three groups of participants (n = 15 / group) were recruited: controls (without diabetes), type II diabetes, and type II diabetes with foot ulcers. All participants underwent MRI evaluating foot perfusion in three muscle layers (from plantar to dorsal) at rest and during a standardized toe-flexion exercise.

Quantative MRI predicts tendon mechanical behavior, collagen composition, and organization.

Quantitative magnetic resonance imaging (qMRI) measures have provided insights into the composition, quality, and structure-function of musculoskeletal tissues. Low signal-to-noise ratio has limited application to tendon. Advances in scanning sequences and sample positioning have improved signal from tendon allowing for evaluation of structure and function.

Remote Research: Resources, Intervention Needs, and Methods in People with Diabetes and Peripheral Neuropathy.

Background: Stay-at-home orders associated with the SARS-CoV-2 (COVID-19) pandemic were particularly important for older adults with type 2 diabetes, at risk for severe COVID-19 complications. In response, research shifted to remote telehealth methodology. Study participant interests, equipment needs, and ability to adapt methods to the remote/telehealth environment were unknown.

Midfoot and ankle movement coordination during heel rise is disrupted in people with diabetes and peripheral neuropathy.

Background: A heel rise task can be used to evaluate midfoot and ankle movement dysfunction in people with diabetes mellitus and peripheral neuropathy. Quantifying movement coordination during heel rise is important to better understand potentially detrimental movement strategies in people with foot pathologies; however, coordination and the impact of limited excursion on coordination is not well-understood in people with diabetes.

Methods: Sixty patients with diabetes mellitus and peripheral neuropathy, and 22 older and 25 younger controls performed single-limb heel rise task.

Computed Tomography and Magnetic Resonance Correlation and Agreement for Foot Muscle and Adipose Tissue Measurements.

Background: Volumetric measures of intrinsic foot muscle and intermuscular adipose tissue (IMAT) infiltration are important in understanding foot injury and disease. We questioned whether measures of muscle and fat derived from computed tomography (CT) and magnetic resonance (MR) would be comparable.

Methods: This study determined the correlation and level of agreement between CT and MR measurements of foot muscle and IMAT from 32 subjects with diabetes and peripheral neuropathy.

Body mass index and maximum available midfoot motion are associated with midfoot angle at peak heel rise in people with type 2 diabetes mellitus and peripheral neuropathy.

Purpose: Midfoot movement dysfunction, as measured by heel rise performance, is associated with midfoot deformity in people with diabetes and peripheral neuropathy. Understanding contributors of midfoot movement dysfunction may help clinicians understand deformity progression. The purpose of this study was to determine the factors associated with midfoot angle at peak heel rise.

Human Achilles tendon mechanical behavior is more strongly related to collagen disorganization than advanced glycation end-products content.

Diabetes is associated with impaired tendon homeostasis and subsequent tendon dysfunction, but the mechanisms underlying these associations is unclear. Advanced glycation end-products (AGEs) accumulate with diabetes and have been suggested to alter tendon function. In vivo imaging in humans has suggested collagen disorganization is more frequent in individuals with diabetes, which could also impair tendon mechanical function.

The Application of Exercise Training for Diabetic Peripheral Neuropathy.

Diabetic peripheral neuropathy (DPN) is the presence of symptoms and/or signs of peripheral nerve dysfunction in people with diabetes after the exclusion of other causes. It is associated with pain, paresthesia, sensory loss, muscle atrophy with fat infiltration, and muscular dysfunction typically starting distally in the feet and progressing proximally. Muscle deterioration within the leg and foot can lead to muscle dysfunction, reduced mobility, and increases the risk of disability, ulceration, and amputation.

A limited number of slices yields comparable results to all slices in foot intrinsic muscle deterioration ratio on computed tomography and magnetic resonance imaging.

Diagnostic imaging modalities, like computed tomography (CT) and magnetic resonance imaging (MRI), can be used to assess in vivo muscle quality. Quantitative assessment using these techniques is time-intensive and costly due in part to extensive post-processing needs. The purpose of this study was to identify whether a subset of slices on CT and MRI would yield comparable results to the full number of slices for a measure of muscle quality (muscle deterioration ratio = fat volume/muscle volume) in the foot intrinsic muscles of people with diabetes and peripheral neuropathy.

Deteriorated regional calf microcirculation measured by contrast-free MRI in patients with diabetes mellitus and relation with physical activity.

Objective: To evaluate regional calf muscle microcirculation in people with diabetes mellitus (DM) with and without foot ulcers, compared to healthy control people without DM, using contrast-free magnetic resonance imaging methods.

Methods: Three groups of subjects were recruited: non-DM controls, DM, and DM with foot ulcers (DM + ulcer), all with ankle brachial index (ABI) > 0.9.

Association of toe-extension movement pattern magnitude and variability during three functional tasks with diabetic foot complications.

Background: A toe-extension movement pattern may contribute to metatarsophalangeal joint deformity and ulceration in people with diabetes. We sought to quantify the relationship between toe extension magnitude and variability during three functional tasks (ankle range of motion, sit to stand, walking) with metatarsophalangeal joint deformity, and identify potential mechanisms associated with a toe-extension movement pattern.

Methods: Individuals with diabetes and peripheral neuropathy were included (n = 60).

Qualitative study of musculoskeletal tissues and their radiographic correlates in diabetic neuropathic foot deformity.

Background: Diabetes mellitus (DM) with peripheral neuropathy (PN) results in foot deformity increasing ulceration, joint dislocation, and amputation risk. This study describes the frequency and severity of foot and ankle musculoskeletal abnormalities and their relationship to radiographic alignment in people with DMPN with (DMPN + MCD) and without (DMPN - MCD) medial column deformity (MCD) compared to age- and body mass index-matched controls without DMPN or MDC.

Methods: DMPN + MCD (n = 11), DMPN - MCD (n = 12), and controls (n = 12) were studied.

Heel Rise and Non-Weight-Bearing Ankle Plantar Flexion Tasks to Assess Foot and Ankle Function in People With Diabetes Mellitus and Peripheral Neuropathy.

Objective: The objective of this study was to examine the effects of diabetes mellitus and peripheral neuropathy (DMPN), limited joint mobility, and weight-bearing on foot and ankle sagittal movements and characterize the foot and ankle position during heel rise.

Methods: Sixty people with DMPN and 22 controls participated. Primary outcomes were foot (forefoot on hindfoot) and ankle (hindfoot on shank) plantar-flexion/dorsiflexion angle during 3 tasks: unilateral heel rise, bilateral heel rise, and non-weight-bearing ankle plantar flexion.

Static Ankle Dorsiflexion and Hip and Pelvis Kinematics During Forward Step-Down in Patients With Hip-Related Groin Pain.

Context: The authors hypothesized that in people with hip-related groin pain, less static ankle dorsiflexion could lead to compensatory hip adduction and contralateral pelvic drop during step-down. Ankle dorsiflexion may be a modifiable factor to improve ability in those with hip-related groin pain to decrease hip/pelvic motion during functional tasks and improve function.

Objective: To determine whether smaller static ankle dorsiflexion angles were associated with altered ankle, hip, and pelvis kinematics during step-down in people with hip-related groin pain.

Midfoot and ankle motion during heel rise and gait are related in people with diabetes and peripheral neuropathy.

Background: Midfoot and ankle movement dysfunction in people with diabetes mellitus and peripheral neuropathy (DMPN) is associated with midfoot deformity and increased plantar pressures during gait. If midfoot and ankle motion during heel rise and push-off of gait have similar mechanics, heel rise performance could be a clinically feasible way to identify abnormal midfoot and ankle function during gait.

Research Question: Is midfoot and ankle joint motion during a heel rise associated with midfoot and ankle motion at push-off during gait in people with DMPN?

Methods: Sixty adults with DMPN completed double-limb heel rise, single-limb heel rise, and walking.

Relationships within and between lower and upper extremity dysfunction in people with diabetes.

Introduction: Diabetes mellitus (DM) is associated with systemic musculoskeletal system impairments suggesting concurrent development of lower and upper extremity musculoskeletal problems. This study aims to examine relationships between lower and upper extremity function in people with DM.

Methods: Sixty people with type 2 DM and peripheral neuropathy [mean (standard deviation); 67(6) years old, DM duration 14(10) yrs] completed the following measures: 1) Self-reports of function: Foot and Ankle Ability Measure (FAAM; higher = better function) and Shoulder Pain and Disability Index (SPADI; lower = better function), 2) Range of motion (goniometry): ankle dorsiflexion and shoulder flexion, and 3) Strength: unilateral heel rise power (UHR, 3D kinetics) and hand grip dynamometry.

Multi-System Factors Associated with Metatarsophalangeal Joint Deformity in Individuals with Type 2 Diabetes.

The underlying factors contributing to metatarsophalangeal joint deformity, a known precursor to skin breakdown in individuals with diabetes mellitus (DM), is likely to involve multiple body systems. The purpose of this cross-sectional study was to identify multi-system factors associated with metatarsophalangeal joint deformity in individuals with type 2 DM and peripheral neuropathy ( = 60). Metatarsophalangeal joint deformity was quantified with a computed tomography (CT) scan.

Skeletal Muscle Regeneration in Advanced Diabetic Peripheral Neuropathy.

Background: Decreased lean muscle mass in the lower extremity in diabetic peripheral neuropathy (DPN) is thought to contribute to altered joint loading, immobility, and disability. However, the mechanism behind this loss is unknown and could derive from a reduction in size of myofibers (atrophy), destruction of myofibers (degeneration), or both. Degenerative changes require participation of muscle stem (satellite) cells to regenerate lost myofibers and restore lean mass.

The Role of Physical Therapists in Fighting the Type 2 Diabetes Epidemic.

Background: In 2014, the total prevalence of diabetes was estimated to be 422 million people worldwide. Due to the aging population and continued increase in obesity rates, the prevalence is expected to rise to 592 million by 2035. Diabetes can lead to several complications, including cardiovascular disease, stroke, peripheral arterial disease, nephropathy, neuropathy, retinopathy, lower extremity amputation, and musculoskeletal impairments.

Intravenous contrast-free standardized exercise perfusion imaging in diabetic feet with ulcers.

Background: Impaired foot perfusion is a primary contributor to foot ulcer formation. There is no existing device nor method that can be used to measure local foot perfusion during standardized foot muscle exercise in an MRI environment.

Purpose: To develop a new MRI-compatible foot dynamometer and MRI methods to characterize local perfusion in diabetic feet with ulcers.