Supersonic shear wave elastography of human tendons is associated with in vivo tendon stiffness over small strains.

Supersonic shear wave (SW) elastography has emerged as a useful imaging modality offering researchers and clinicians a fast, non-invasive, quantitative assessment of tendon biomechanics. However, the exact relationship between SW speed and in vivo tendon stiffness is not intuitively obvious and needs to be verified. This study aimed to explore the validity of supersonic SW elastography against a gold standard method to measure the Achilles tendon's in vivo tensile stiffness by combining conventional ultrasound imaging with dynamometry. Twelve healthy participants performed maximal voluntary isometric plantarflexion contractions (MVC) on a dynamometer with simultaneous ultrasonographic recording of the medial gastrocnemius musculotendinous junction for dynamometry-based measurement of stiffness. The tendon's force-elongation relationship and stress-strain behaviour were assessed. Tendon stiffness at different levels of tension was calculated as the slope of the stress-strain graph. SW speed was measured at the midportion of the free tendon and tendon Young's modulus was estimated. A correlation analysis between the two techniques revealed a statistically significant correlation for small strains (r(10) = 0.604, p =.038). SW-based assessments of in vivo tendon stiffness were not correlated to the gold standard method for strains in the tendon>10 % of the maximum strain during MVC. The absolute values of SW-based Young's modulus estimations were approximately-three orders of magnitude lower than dynamometry-based measurements. Supersonic SW elastography should be only used to assess SW speed for the detection and study of differences between tissue regions, differences between people or groups of people or changes over time in tendon initial stiffness (i.e., stiffness for small strains).

Elastography in the assessment of the Achilles tendon: a systematic review of measurement properties.

BACKGROUND: Managing and rehabilitating Achilles tendinopathy can be difficult, and the results are often unsatisfactory. Currently, clinicians use ultrasonography to diagnose the condition and predict symptom development. However, relying on subjective qualitative findings using ultrasound images alone, which are heavily influenced by the operator, may make it difficult to identify changes within the tendon. New technologies, such as elastography, offer opportunities to quantitatively investigate the mechanical and material properties of the tendon. This review aims to evaluate and synthesise the current literature on the measurement properties of elastography, which can be used to assess tendon pathologies. METHODS: A systematic review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. CINAHL, PubMed, Cochrane, Scopus, MEDLINE Complete, and Academic Search Ultimate were searched. Studies assessing the measurement properties concerning reliability, measurement error, validity, and responsiveness of the instruments identified in healthy and patients with Achilles tendinopathy were included. Two independent reviewers assessed the methodological quality using the Consensus-based Standards for the Selection of Health Measurement Instruments methodology. RESULTS: Out of the 1644 articles identified, 21 were included for the qualitative analysis investigating four different modalities of elastography: axial strain elastography, shear wave elastography, continuous shear wave elastography, and 3D elastography. Axial strain elastography obtained a moderate level of evidence for both validity and reliability. Although shear wave velocity was graded as moderate to high for validity, reliability obtained a very low to moderate grading. Continuous shear wave elastography was graded as having a low level of evidence for reliability and very low for validity. Insufficient data is available to grade three-dimensional shear wave elastography. Evidence on measurement error was indeterminate so evidence could not be graded. CONCLUSIONS: A limited number of studies explored quantitative elastography on Achilles tendinopathy as most evidence was conducted on a healthy population. Based on the identified evidence on the measurement properties of elastography, none of the different types showed superiority for its use in clinical practice. Further high-quality studies with longitudinal design are needed to investigate responsiveness.

A Biomechanical Investigation of Children with Type 1 Diabetes Mellitus: Are Children's Feet a Precursor to Adulthood Foot Complications?

BACKGROUND: There is limited evidence on the biomechanical effects of type 1 diabetes mellitus (T1DM) on children's feet. This study aimed to determine whether children living with T1DM aged 10 to 16 years have altered foot structure and gait parameters compared with same-aged children without medical conditions. METHODS: A nonexperimental, case-control study was conducted. Thirty-four healthy children and children living with T1DM were recruited. Participants underwent a clinical biomechanical examination followed by instrumented gait analysis using the Oxford Foot Model to investigate foot segment motion. RESULTS: Children with T1DM demonstrated more dermatologic lesions and structural foot abnormalities, including claw toes (33.3%), hammertoes (22.2%), and hallux abducto valgus (11.1%), than their healthy counterparts. Gait analysis results indicate a significant difference between the two groups at the hindfoot-to-tibia angle at heel strike and toe-off, suggesting limited ankle joint motion. CONCLUSIONS: Children with T1DM demonstrated a higher frequency of structural foot pathologies than did healthy children possibly associated with limited ankle sagittal plane movement. Screening is warranted to identify and manage these conditions early to reduce their risk of more significant foot problems associated with DM in adulthood.

The Effects of Skin Temperature Changes on the Integrity of Skin Tissue: A Systematic Review.

OBJECTIVE: To determine whether changes in skin temperature can affect the integrity of skin. METHODOLOGY: The authors conducted a systematic literature search as per the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines. They searched the CINAHL (Cumulative Index to Nursing and Allied Health Literature), Cochrane, MEDLINE Complete, Academic Search Ultimate, and HyDi databases for articles examining the effects of skin temperature on skin integrity published through April 2020. Two independent reviewers scored the methodologic quality of the 13 included studies. RESULTS: Only 11 studies were included in the qualitative analysis, as the other two articles had a critical risk of bias. There is strong evidence to indicate that an increase in skin temperature leads to changes in skin structure and function. However, ulcer formation was more affected by intrinsic and extrinsic factors, rather than by temperature alone. CONCLUSION: Further high-quality randomized controlled trials are required to investigate the direct effect of skin temperature on ulceration.

Severity of pronation and classification of first metatarsophalangeal joint dorsiflexion increases the validity of the Hubscher Manoeuvre for the diagnosis of functional hallux limitus.

BACKGROUND: Functional hallux limitus (FHL) is diagnosed with a static test known as the Hubscher Manoeuvre, the validity of which has been previously questioned. OBJECTIVES: To investigate the validity of this Manoeuvre and whether introducing severity of pronation as a second concurrent test would increase this validity. METHOD: 30 participants with a hallux dorsiflexion <12° were divided into 2 equal groups, depending on their severity of pronation according to the Foot Posture Index. A single video camera, placed perpendicular to the plane of motion of the 1st MPJ, captured its movement, from which the angle of maximum dorsiflexion of this joint was measured. RESULTS: 10 males and 20 females, aged 18-56 years (mean 28 yrs, SD ± 12.1 yrs) participated. There was no significant relationship between non-weight bearing and dynamic maximum dorsiflexion (p=0.160), and between weight bearing and dynamic maximum dorsiflexion (p=0.865). A significant relationship between 1st MPJ dynamic maximum dorsiflexion and severity of pronation (p=0.004) was found. CONCLUSIONS: None of the participants exhibited a complete lack of hallux dorsiflexion. A positive Hubscher Manoeuvre test, on its own, is not a good indicator of limited 1st MPJ dorsiflexion during dynamic motion. However, as pronation increases, 1st MPJ maximum dorsiflexion during gait decreases.