Feasibility of an early progressive resistance exercise program for acute Achilles tendon rupture.

BACKGROUND: Long-term strength deficits are common after Achilles tendon ruptures. Early use of progressive resistance exercises may help reduce strength deficits, but the feasibility of this approach is unknown. The aim was to investigate the feasibility of early progressive resistance exercises regarding patient acceptability and compliance with the intervention. METHODS: We recruited patients with an acute Achilles tendon rupture treated non-surgically. During 9 weeks of immobilisation with a walking boot, participants attended weekly supervised physiotherapy sessions of progressive resistance exercises and performed home exercises, consisting of isometric ankle plantarflexion, seated heel-rise, and elastic band exercises. Acceptability was evaluated using a 7-point Likert scale (1 = very unacceptable and 7 = very acceptable) with feasibility threshold at 80% of the participants rating ≥ 4. Adherence to the exercises was defined as 80% of the participants performing at least 50% of the home exercises. During the intervention, tendon healing and adverse events were monitored. RESULTS: Sixteen participants (mean age 46 (range 28-61), male/female = 13/3) completed the intervention. Pre-injury Achilles tendon total rupture score was 98 (SD 8). All participants rated the acceptability of the exercises ≥ 5 (moderate acceptable to very acceptable) at 9- and 13-week follow-up and 9/16 rated 7 points (very acceptable). Participants performed 74% (range 4-117) of the total prescribed home exercises and 15/16 performed > 50%. One participant was not compliant with the home exercises due to feeling uncomfortable performing these independently. There were no re-ruptures, but one case of deep venous thrombosis. CONCLUSIONS: The early progressive resistance exercise program for treatment of non-surgically treated Achilles tendon rupture was feasible. Future studies should investigate the efficacy of the progressive intervention. TRIAL REGISTRATION: The study was registered at Clinical Trials (NCT04121377) on 29 September 2019. CLINICALTRIALS: NCT04121377 .

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. METHODS: Participants with DM and PN (n = 60) were included in this longitudinal cohort study. Rate of BMD change of individual bones was monitored using computed tomography at baseline and 6 months, 18 months, and 3-4 years from baseline. Personal factors (age, sex, medication use, step count, sedentary time, and PN severity) were assessed. A random coefficient model estimated rate of change of BMD in all bones and Pearson correlation tested relationships between personal factor variables and rate of BMD change. RESULTS: Mean and calcaneal BMD decreased over the study period (p < 0.05). Individual tarsal and metatarsal bones present a range of rate of BMD change (-0.3 to -0.9%/year) but were not significantly different than calcaneal BMD change. Only age showed significant correlation with BMD and rate of BMD change. CONCLUSION: The rate of BMD change did not significantly differ across different foot bones at the group level in people with DM and PN without foot deformity. Asymmetric BMD loss between individual bones of the foot and aging may be indicators of pathologic changes and require further investigation. TRIAL REGISTRATION: Metatarsal Phalangeal Joint Deformity Progression-R01. Registered 25 November 2015, https://clinicaltrials.gov/ct2/show/NCT02616263.

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. The exercise perfusion and perfusion reserve values were analyzed around and away from ulcers. Participants with foot ulcers were followed up 3 months after the MRI exams to determine the foot healing status. RESULTS: Foot plantar muscle perfusion reserves were progressively lower from controls to diabetes, and to diabetes with foot ulcers (e.g., 2.58 ± 0.67, 1.48 ± 0.71, 1.12 ± 0.35, p < 0.001). In controls, the plantar layer had significantly higher perfusion reserve than the dorsal layer, whereas in either diabetes group, there was no significant difference in perfusion reserve among muscle layers. Using the ratio of total exercise perfusion around ulcers to that away from ulcers, the sensitivity and specificity to differentiate healing from non-healed ulcers were 100% and 86%, respectively. CONCLUSIONS: Our study reveals significantly different foot perfusion distribution among controls, diabetes, and diabetes with foot ulcers. The prognostic value of MRI regional perfusion assessments has the potential to monitor interventions to improve ulcer healing outcomes. KEY POINTS: • Contrast-free MRI permits quantitative assessment of regional foot muscle perfusion at rest and during isometric exercise. • Patients with diabetes and foot ulcers, without clinical evidence of peripheral arterial disease, had significantly impaired foot muscle perfusion and perfusion reserve. • Regional foot perfusion distribution may be used to predict the short-term healing status of foot ulcers in diabetes.

Fascicular elastin within tendon contributes to the magnitude and modulus gradient of the elastic stress response across tendon type and species.

Elastin, the main component of elastic fibers, has been demonstrated to significantly influence tendon mechanics using both elastin degradation studies and elastinopathic mouse models. However, it remains unclear how prior results differ between species and functionally distinct tendons and, in particular, how results translate to human tendon. Differences in function between fascicular and interfascicular elastin are also yet to be fully elucidated. Therefore, this study evaluated the quantity, structure, and mechanical contribution of elastin in functionally distinct tendons across species. Tendons with an energy-storing function had slightly more elastin content than tendons with a positional function, and human tendon had at least twice the elastin content of other species. While distinctions in the organization of elastic fibers between fascicles and the interfascicular matrix were observed, differences in structural arrangement of the elastin network between species and tendon type were limited. Mechanical testing paired with enzyme-induced elastin degradation was used to evaluate the contribution of elastin to tendon mechanics. Across all tendons, elastin degradation affected the elastic stress response by decreasing stress values while increasing the modulus gradient of the stress-strain curve. Only the contributions of elastin to viscoelastic properties varied between tendon type and species, with human tendon and energy-storing tendon being more affected. These data suggest that fascicular elastic fibers contribute to the tensile mechanical response of tendon, likely by regulating collagen engagement under load. Results add to prior findings and provide evidence for a more mechanistic understanding of the role of elastic fibers in tendon. STATEMENT OF SIGNIFICANCE: Elastin has previously been shown to influence the mechanical properties of tendon, and degraded or abnormal elastin networks caused by aging or disease may contribute to pain and an increased risk of injury. However, prior work has not fully determined how elastin contributes differently to tendons with varying functional demands, as well as within distinct regions of tendon. This study determined the effects of elastin degradation on the tensile elastic and viscoelastic responses of tendons with varying functional demands, hierarchical structures, and elastin content. Moreover, volumetric imaging and protein quantification were used to thoroughly characterize the elastin network in each distinct tendon. The results presented herein can inform tendon-specific strategies to maintain or restore native properties in elastin-degraded tissue.

Effect of Diabetes on Tendon Structure and Function: Not Limited to Collagen Crosslinking.

Diabetes mellitus (DM) is associated with musculoskeletal complications-including tendon dysfunction and injury. Patients with DM show altered foot and ankle mechanics that have been attributed to tendon dysfunction as well as impaired recovery post-tendon injury. Despite the problem of DM-related tendon complications, treatment guidelines specific to this population of individuals are lacking. DM impairs tendon structure, function, and healing capacity in tendons throughout the body, but the Achilles tendon is of particular concern and most studied in the diabetic foot. At macroscopic levels, asymptomatic, diabetic Achilles tendons may show morphological abnormalities such as thickening, collagen disorganization, and/or calcific changes at the tendon enthesis. At smaller length scales, DM affects collagen sliding and discrete plasticity due to glycation of collagen. However, how these alterations translate to mechanical deficits observed at larger length scales is an area of continued investigation. In addition to dysfunction of the extracellular matrix, tendon cells such as tenocytes and tendon stem/progenitor cells show significant abnormalities in proliferation, apoptosis, and remodeling capacity in the presence of hyperglycemia and advanced glycation end-products, thus contributing to the disruption of tendon homeostasis and healing. Improving our understanding of the effects of DM on tendons-from molecular pathways to patients-will progress toward targeted therapies in this group at high risk of foot and ankle morbidity.

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. Study purposes to assess (1) resource needs (internet/devices accessibility), (2) future telehealth interests, and (3) ability to adapt common research and clinical measures of glycemic control, physical function, activity measures, and quality of life outcomes to a telehealth setting. METHOD: Twenty-one participants with type 2 diabetes and peripheral neuropathy were recruited from a longitudinal study (11 female; age: 66.3 ± 8.3 years; DM: 15.1 ± 8.7 years). Technology needs and future telehealth interests were assessed. A glycemic measure (HbA1c), a five-times chair rise, a one-week activity monitor, and surveys (self-efficacy, depression, and balance) were collected. All aspects of the study were completed remotely over email and video/phone call. RESULTS: Twelve participants used computers; nine used phones for study completion. Participants had the following resource needs: connectivity (n = 3), devices (n = 6), and technical support (n = 12). Twenty people expressed interest in participating in future telehealth studies related to balance, exercise, and diabetes management. Methodological considerations were primarily the need for assistance for participants to complete the home HbA1c test, five-time chair rise, wearable activity monitoring, and surveys. CONCLUSIONS: Older adults with type 2 diabetes and peripheral neuropathy would need technological and personal assistance (connection, device, guidance) to complete a long-term telehealth intervention. Despite technology needs, participants were interested in telehealth interventions. CLINICAL TRIAL: Parent study, "Metatarsal Phalangeal Joint Deformity Progression-R01 (NCT02616263) is registered at https://clinicaltrials.gov/.

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. The purpose of this study was to elucidate relationships between tendon qMRI metrics (T1, T2, T1ρ and diffusion tensor imaging [DTI] metrics) with tendon tissue mechanics, collagen concentration and organization. Sixteen human Achilles tendon specimens were collected, imaged with qMRI, and subjected to mechanical testing with quantitative polarized light imaging. T2 values were related to tendon mechanics [peak stress (rsp = 0.51, p = 0.044), equilibrium stress (rsp = 0.54, p = 0.033), percent relaxation (rsp = -0.55, p = 0.027), hysteresis (rsp = -0.64, p = 0.007), linear modulus (rsp = 0.67, p = 0.009)]. T1ρ had a statistically significant relationship with percent relaxation (r = 0.50, p = 0.048). Collagen content was significantly related to DTI measures (range of r = 0.56-0.62). T2 values from a single slice of the midportion of human Achilles tendons were strongest predictors of tendon tensile mechanical metrics. DTI diffusivity indices (mean diffusivity, axial diffusivity, radial diffusivity) were strongly correlated with collagen content. These findings build on a growing body of literature supporting the feasibility of qMRI to characterize tendon tissue and noninvasively measure tendon structure and function. Statement of Clinical Significance: Quantitative MRI can be applied to characterize tendon tissue and is a noninvasive measure that relates to tendon composition and mechanical behavior.

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. Midfoot (forefoot relative to hindfoot) sagittal and ankle (hindfoot relative to shank) sagittal and frontal kinematics were measured and normalized to time (0 to 100%). Cross-correlation coefficients were calculated across individuals in each group. A graphical illustration was used to interpret the relationship of midfoot and ankle excursion and cross-correlation coefficient during heel rise. FINDINGS: People with diabetes mellitus and peripheral neuropathy showed significantly lower midfoot and ankle cross-correlation coefficients during heel rise compared to older controls (p = 0.003-0.007). There was no difference in the midfoot and ankle cross-correlation coefficients during heel rise for the older and younger controls (p = 0.059-0.425). The graphic data illustrated a trend of greater excursion of two joints and a higher cross-correlation coefficient. Some individuals with lower excursion showed a high cross-correlation coefficient. INTERPRETATION: Foot pathologies, but not aging, impairs midfoot and ankle movement coordination during heel rise task. Investigating both movement coordination as well as joint excursion would better inform and characterize the dynamic movements of midfoot and ankle during heel rise task.

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. METHODS: The outcomes of fifty-eight participants with type 2 diabetes mellitus and peripheral neuropathy were analyzed. Midfoot (forefoot on hindfoot) sagittal kinematics during unilateral heel rise task were measured using 3-dimensional motion analysis. A multivariate linear regression model was used to predict midfoot sagittal movements at peak heel rise. Independent variables that were entered in the model were (in order of entry): age, body mass index, intrinsic foot muscle volume, and maximum available midfoot plantarflexion range of motion. Intrinsic foot muscle volume was obtained from magnetic resonance imaging and maximum available midfoot motion was measured during non-weightbearing plantarflexion using 3-dimensional motion analysis. RESULTS: Body mass index (R2 = 30.5%, p < 0.001) and maximum available midfoot plantarflexion range of motion (R2 = 10.9%, p = 0.001) were significant factors that accounted for 41.4% of variance of midfoot angle at peak heel rise, while age and intrinsic foot muscle volume were not significant predictors. CONCLUSIONS: Greater body mass index and less available midfoot plantarflexion range of motion were associated with greater midfoot movement dysfunction. These two significant predictors are potentially modifiable, suggesting possible improvements in midfoot movements with reduction in body weight and increasing midfoot plantarflexion range of motion. Health care professionals should consider patient's weight and joint motion when prescribing foot exercise(s) to prevent excessive midfoot collapse during weightbearing tasks.

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 purpose of this study was to examine relationships between tendon tensile mechanics in human Achilles tendon with accumulation of advanced glycation end-products and collagen disorganization. Achilles tendon specimens (n = 16) were collected from individuals undergoing lower extremity amputation or from autopsy. Tendons were tensile tested with simultaneous quantitative polarized light imaging to assess collagen organization, after which AGEs content was assessed using a fluorescence assay. Moderate to strong relationships were observed between measures of collagen organization and tendon tensile mechanics (range of correlation coefficients: 0.570-0.727), whereas no statistically significant relationships were observed between AGEs content and mechanical parameters (range of correlation coefficients: 0.020-0.210). Results suggest that the relationship between AGEs content and tendon tensile mechanics may be masked by multifactorial collagen disorganization at larger length scales (i.e., the fascicle level).

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. CT (0.6 mm slice thickness) and MRI (3.5 mm slice thickness) scans were obtained using previously described methods. The total number of slices acquired during the scan was compared to several conditions using a portion of slices. Bland-Altman plots and Lin's concordance correlation coefficient were used to test agreement. Any condition using at least three slices yielded substantial to almost perfect agreement with the total number of slices on both CT and MRI (Range of Lin's concordance correlation coefficient: 0.947-0.999). Using a single slice in the middle of the region of interest demonstrated poor to moderate agreement with the total number of slices. The findings of this study suggest that using a limited number of slices to quantify muscle deterioration ratio on CT or MRI is a viable way to balance the combined need for measurement accuracy with feasibility in research and clinical settings.

Functional Ankle Range of Motion but Not Peak Achilles Tendon Force Diminished With Heel-Rise and Jumping Tasks After Achilles Tendon Repair.

BACKGROUND: Deficits in sporting performance after Achilles tendon repair may be due to changes in musculotendinous unit structure, including tendon elongation and muscle fascicle shortening. PURPOSE/HYPOTHESIS: The purpose was to discern whether Achilles tendon rupture reduces triceps surae muscle force generation, alters functional ankle range of motion, or both during sports-related tasks. We hypothesized that individuals who have undergone Achilles tendon repair lack the functional ankle range of motion needed to complete sports-related tasks. STUDY DESIGN: Descriptive laboratory study. METHODS: The study included individuals 1 to 3 years after treatment of Achilles tendon rupture with open repair. Participants (n = 11) completed a heel-rise task and 3 jumping tasks. Lower extremity biomechanics were analyzed using motion capture. Between-limb differences were tested using paired t test. RESULTS: Pelvic vertical displacement was reduced during the heel-rise (mean difference, -12.8%; P = .026) but not during the jumping task (P > .1). In the concentric phase of all tasks, peak ankle plantarflexion angle (range of mean difference, -19.2% to -48.8%; P < .05) and total plantar flexor work (defined as the area under the plantar flexor torque - ankle angle curve) (range of mean difference, -9.5% to -25.7%; P < .05) were lower on the repaired side relative to the uninjured side. No significant differences were seen in peak Achilles tendon load or impulse with any of the tasks. There were no differences in plantar flexor work or Achilles tendon load parameters during eccentric phases. CONCLUSION: Impaired task performance or increased demands on proximal joints were observed on the repaired side in tasks isolating ankle function. Tasks that did not isolate ankle function appeared to be well recovered, although functional ankle range of motion was reduced with rupture. Reduced plantar flexor muscle-tendon unit work supports previous reports that an elongated tendon and shorter muscle fascicles caused by Achilles tendon rupture constrain functional capacity. Achilles tendon peak load and impulse were not decreased, suggesting that reduced and shifted functional ankle range of motion (favoring dorsiflexion) underlies performance deficits. CLINICAL RELEVANCE: These findings point to the need to reduce tendon elongation and restore muscle length of the triceps surae after Achilles tendon rupture in order to address musculature that is short but not necessarily weak for improved performance with sports-related activities.

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). Metatarsophalangeal joint deformity was assessed using computed tomography (CT). Toe-extension movement was quantified using 3-dimensional motion capture. Linear regression was used to investigate the role of toe-extension movement pattern on metatarsophalangeal joint deformity. Regression analysis was used to identify mechanisms (neuropathy severity, foot intrinsic muscle deterioration ratio, ankle dorsiflexion range of motion) contributing to toe-extension movement pattern. FINDINGS: Toe extension with each functional task as well as the mean and coefficient of variation across all tasks were significantly related to metatarsophalangeal joint deformity (range of correlation coefficients = (-0.386, 0.692), p ≤ 0.001). Ankle dorsiflexion range of motion was associated with mean toe extension across all tasks (rsp = -0.282, p = 0.029). Neuropathy severity and foot intrinsic muscle deterioration ratio were associated with toe extension variability (rsp = -0.373, p = 0.003 and rsp = -0.266, p = 0.043; respectively). INTERPRETATION: Greater magnitude and lower variability of a toe-extension movement pattern was found to be associated with metatarsophalangeal joint deformity. These findings may support clinical assessment and treatment of movement across more than one task.

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. A radiologist scored foot and ankle magnetic resonance images (MRI) for abnormalities in tendons/fascia, ligaments, muscles, joints, and bones. Higher scores represent greater abnormalities. Foot alignment was measured from lateral weightbearing radiographs. Frequency of abnormalities between groups and relationships between abnormalities and foot alignment in the combined group (n = 35) were examined. RESULTS: DMPN + MCD had higher total muscle, joint, and bone scores compared to controls and higher total joint scores than DMPN - MCD. DMPN - MCD had higher total muscle scores than controls. DMPN + MCD higher bone and joint scores were driven by increased frequency of osteophytes, cartilage damage, focal bone marrow edema, new bone formation, and subchondral cysts. Significant correlations included cuboid height and total bone and joint scores (ρ = -0.37 and ρ = -0.40, respectively) and talar declination angle and total joint score (ρ = 0.38). CONCLUSION: High contrast resolution MRI allowed identification of structural lesions of the foot affecting the cartilage surfaces, bone marrow, and soft tissue supports in patients with DMPN + MCD. As expected, the presence of bone and joint lesions on MRI were strongly associated with DMPN + MCD; surprisingly, although the sample is small, lesions of the soft tissue supports were not associated with MCD. While MRI is not done routinely to investigate MCD, opportunistic use of the information from MRI done for the common clinical indications may allow early identification of the structural lesions associated with MCD and facilitate early, aggressive therapy. LEVEL OF EVIDENCE: III.

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. A repeated-measures analysis of variance and Fisher exact test were used. RESULTS: Main effects of task and group were significant, but not the interaction in both foot and ankle plantar flexion. Foot and ankle plantar flexion were less in people with DMPN compared with controls in all tasks. Both DMPN and control groups had significantly less foot and ankle plantar flexion with greater weight-bearing; however, the linear trend across tasks was similar between groups. The DMPN group had a greater percentage of individuals in foot and/or ankle dorsiflexion at peak unilateral heel rise compared with controls, but the foot and ankle position was similar at peak bilateral heel rise between DMPN and control groups. CONCLUSION: Foot and ankle plantar flexion is less in people with DMPN. Less plantar flexion in non-weight-bearing suggests that people with DMPN have limited joint mobility. However, peak unilateral and bilateral heel rise is less than the available plantar flexion range of motion measured in non-weight-bearing, indicating that limited joint mobility does not limit heel rise performance. A higher frequency of people with DMPN are in foot and ankle dorsiflexion at peak unilateral heel rise compared with controls, but the position improved with lower weight-bearing. IMPACT: Proper resistance should be considered with physical therapist interventions utilizing heel rise because foot and ankle plantar flexion position could be improved by reducing the amount of weight-bearing.

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. A modified Oxford multi-segment foot model (forefoot, hindfoot, shank) was used to analyze midfoot (forefoot on hindfoot) and ankle (hindfoot on shank) sagittal angle during heel rise and gait. Pearson correlation was used to test the relationship between heel rise and gait kinematic variables (n = 60). Additionally, we classified 60 participants into two subgroups based on midfoot and ankle position at peak heel rise: midfoot and ankle dorsiflexed (dorsiflexed; n = 23) and midfoot and ankle plantarflexed (plantarflexed; n = 20). Movement trajectories of midfoot and ankle motion during single-limb heel rise and gait of the subgroups were examined. RESULTS: Peak double-limb heel rise and gait midfoot and ankle angles were significantly correlated (r = 0.49 and r = 0.40, respectively). Peak single-limb heel rise and gait midfoot and ankle angles were significantly correlated (r = 0.63 and r = 0.54, respectively). The dorsiflexed subgroup, identified by heel rise performance showed greater midfoot and ankle dorsiflexion during gait compared to the plantarflexed subgroup (mean difference between subgroups: midfoot 3°, ankle 3°). SIGNIFICANCE: People with DMPN who fail to plantarflex the midfoot and ankle during heel rise have difficulty plantarflexing the midfoot and ankle during gait. Utilizing a heel rise task may help identify midfoot and ankle dysfunction associated with gait in people with DMPN.

Resistance Exercises in Early Functional Rehabilitation for Achilles Tendon Ruptures Are Poorly Described: A Scoping Review.

OBJECTIVES: To (1) describe which resistance exercises are used in the first 8 weeks of treatment for acute Achilles tendon rupture and (2) assess the completeness of reporting of the exercise descriptions. DESIGN: Scoping review. LITERATURE SEARCH: We searched the MEDLINE, Embase, CINAHL, Cochrane Library, and Physiotherapy Evidence Database (PEDro) databases. STUDY SELECTION CRITERIA: Randomized controlled trials, cohort studies, and case series (10 or more participants) that reported using resistance exercise in the immobilization period in the first 8 weeks of treatment for acute Achilles tendon rupture were included. DATA SYNTHESIS: Completeness of exercise description was assessed with the Consensus on Exercise Reporting Template (CERT) and the Toigo and Boutellier exercise descriptor framework. RESULTS: Thirty-eight studies were included. Fifty-one resistance exercises were extracted and categorized as isometric exercises (n = 20), heel raises (n = 6), strengthening with external resistance (n = 13), or unspecified (n = 12). A median of 8 (interquartile range, 6-10) of a possible 19 CERT items was reported. The amount of items described of the 13 Toigo and and Boutellier exercise descriptors ranged from 0 to 11. CONCLUSION: A variety of resistance exercises targeted at the ankle plantar flexors were used as part of early functional rehabilitation after Achilles tendon rupture. However, most studies provided inadequate description of resistance exercise interventions. J Orthop Sports Phys Ther 2020;50(12):681-691. Epub 23 Oct 2020. doi:10.2519/jospt.2020.9463.

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. Pearson correlations examined associations between lower and upper extremity measures, p < .05. RESULTS: Forty of 60 (67%) reported pain/disability in both the foot/ankle and shoulder and 95% of study participants had some limitation in foot or shoulder function. Significant between extremity correlations: FAAM and SPADI (r = -0.39), ankle dorsiflexion and shoulder flexion range of motion (r = 0.35), and UHR and hand grip strength (r = 0.40). Significant within extremity correlations: FAAM and UHR (r = .47) and SPADI with shoulder flexion (r = -0.44). CONCLUSION: Upper and lower extremity inter- and intra-relationships indicate systemic musculoskeletal impairments in people with DM. Healthcare practitioners should consider the potential for concurrent and disabling musculoskeletal problems in people with DM.

Impact of seated and standing positions on triceps surae muscle activation in unilateral Achilles tendon rupture.

Heel-rises are commonly used in the rehabilitation of individuals following Achilles tendon rupture, however, the impact of tendon elongation on triceps surae activation in seated versus standing positions has not been investigated. The purpose of this study was to investigate changes in triceps surae activation during seated compared to standing heel-rises in individuals with Achilles tendon rupture and its relationship to tendon elongation. Ten individuals with a history of Achilles tendon rupture were included in this study. Muscle activity using electromyography was examined during a heel-rise task in seated (unilateral) and standing (bilateral) positions. Soleus activity was not significantly different between sitting and standing on both the ruptured and uninjured side. On the ruptured, side there were no differences in medial or lateral gastrocnemius activity between sitting and standing; however, on the uninjured side medial and lateral gastrocnemius activity was lower in sitting compared to standing. The results of this study suggest that neuromuscular changes in triceps surae activation occur following Achilles tendon rupture. The seated heel-rise position can be used to strengthen all muscles of the triceps surae and is useful when the patient is unable to perform a standing heel-rise.

Age and Tightness of Repair Are Predictors of Heel-Rise Height After Achilles Tendon Rupture.

BACKGROUND: Achilles tendon rupture leads to weakness of ankle plantarflexion. Treatment of Achilles tendon rupture should aim to restore function while minimizing weakness and complications of management. PURPOSE: To determine the influence of factors (age, sex, body mass index [BMI], weight, time from injury to operative repair, and tightness of repair) in the initial surgical management of patients after an acute Achilles tendon rupture on 12-month functional outcome assessment after percutaneous and minimally invasive repair. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: From May 2012 to January 2018, patients sustaining an Achilles tendon rupture receiving operative repair were prospectively evaluated. Tightness of repair was quantified using the intraoperative Achilles tendon resting angle (ATRA). Heel-rise height index (HRHI) was used as the primary 12-month outcome variable. Secondary outcome measures included Achilles tendon total rupture score (ATRS) and Tegner score. Stepwise multiple regression was used to create a model to predict 12-month HRHI. RESULTS: A total of 122 patients met the inclusion criteria for data analysis (mean ± SD age, 44.1 ± 10.8 years; 78% male; mean ± SD BMI, 28.1 ± 4.3 kg/m2). The elapsed time to surgery was 6.5 ± 4.0 days. At 12-month follow-up, patients had an HRHI of 82% ± 16% and performed 82% ± 17% of repetitions compared with the noninjured side. Participants had a mean ATRS of 87 ± 15 and a median Tegner score of 5 (range, 1-9), with a reduction in Tegner score of 2 from preinjury levels. The relative ATRA at 12 months was -4.8° ± 3.9°. Multiple regression identified younger age (B = ±0.006; P < .001) and greater intraoperative ATRA (B = 0.005; P = .053) as predictors of more symmetrical 12-month HRHI (R 2 = 0.19; P < .001; n = 120). CONCLUSION: Age was found to be the strongest predictor of outcome after Achilles tendon rupture. The most important modifiable risk factor was the tightness of repair. It is recommended that repair be performed as tight as possible to optimize heel-rise height 1 year after Achilles tendon rupture and possibly to reduce tendon elongation.