In situ force distribution in the glenohumeral joint capsule during anterior-posterior loading

AbstractRolling adhesion is a unique process in which the adhesion events are short-lived and operate under highly non-equilibrium conditions. These characteristics pose a challenge in molecular force quantification, where in situ measurement of such forces cannot be achieved with most molecular force sensors that probe near equilibrium. In this report, we demonstrated a quantitative adhesion footprint assay combining DNA-based non-equilibrium force probes and modelling to measure the molecular force involved in fast rolling adhesion. We were able to directly profile the ensemble molecular force distribution during rolling adhesion with a dynamic range between 0 – 18 pN. Our results showed that the shear stress driving bead rolling motility directly controls the molecular tension on the probe-conjugated adhesion complex. Furthermore, the shear stress can steer the dissociation bias of components within the molecular force probe complex, favouring either DNA probe dissociation or receptor-ligand dissociation.

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Isolating In-Situ Grip and Push Force Distribution from Hand-Handle Contact Pressure with an Industrial Electric Nutrunner

Sensors ◽

10.3390/s21238120 ◽

2021 ◽

Vol 21 (23) ◽

pp. 8120

Author(s):

Cederick Landry ◽

Daniel Loewen ◽

Harish Rao ◽

Brendan L. Pinto ◽

Robert Bahensky ◽

...

Keyword(s):

Grip Force ◽

Pressure Sensors ◽

Measurement Instrument ◽

Force Distribution ◽

Pressure Measurements ◽

Industrial Workers ◽

Shoulder Injuries ◽

Significant Difference ◽

Measured Pressure

Objectives: Grip force during hand tool operation is the primary contributor to tendon strain and related wrist injuries, whereas push force is a contributor to shoulder injuries. However, both cannot be directly measured using a single measurement instrument. The objective of this research was to develop and test an algorithm to isolate the grip and push force distributions from in-situ hand-handle pressure measurements and to quantify their distributions among industrial workers using an electric nutrunner. Methods: Experienced automobile assembly line workers used an industrial nutrunner to tighten fasteners at various locations and postures. The pressure applied by the hand on the tool handle was measured dynamically using pressure sensors mounted on the handle. An algorithm was developed to compute the push force applied to the handle of an electric pistol-grip nutrunner based on recorded pressure measurements. An optimization problem was solved to find the contribution of each measured pressure to the actual pushing force of the tool. Finally, the grip force was determined from the difference between the measured pressure and the calculated pushing pressure. Results: The grip force and push force were successfully isolated and there was no correlation between the two forces. The computed grip force increased from low to high fastener locations, whereas the push force significantly increased during overhead fastening. A significant difference across the participants’ computed grip forces was observed. The grip force distribution showed that its contribution to total hand force was larger than other definitions in the literature. Conclusions: The developed algorithm can aid in better understanding the risk of injury associated with different tasks through the notion of grip and push force distribution. This was shown to be important as even workers with considerable power tool experience applied significantly more grip and push force than other participants, all of whom successfully completed each task. Moreover, the fact that both forces were uncorrelated shows the need for extracting them independently.

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Developmental Patterning and Neurogenetic Gradients of Nurr1 Positive Neurons in the Rat Claustrum and Lateral Cortex

Frontiers in Neuroanatomy ◽

10.3389/fnana.2021.786329 ◽

2021 ◽

Vol 15 ◽

Author(s):

Chao Fang ◽

Hong Wang ◽

Robert Konrad Naumann

Keyword(s):

Expression Patterns ◽

Prenatal Development ◽

Superficial Layer ◽

Lateral Cortex ◽

Developmental Progression ◽

Previous Birth ◽

Developmental Patterning ◽

And Function ◽

Anterior Posterior

The claustrum is an enigmatic brain structure thought to be important for conscious sensations. Recent studies have focused on gene expression patterns, connectivity, and function of the claustrum, but relatively little is known about its development. Interestingly, claustrum-enriched genes, including the previously identified marker Nurr1, are not only expressed in the classical claustrum complex, but also embedded within lateral neocortical regions in rodents. Recent studies suggest that Nurr1 positive neurons in the lateral cortex share a highly conserved genetic expression pattern with claustrum neurons. Thus, we focus on the developmental progression and birth dating pattern of the claustrum and Nurr1 positive neurons in the lateral cortex. We comprehensively investigate the expression of Nurr1 at various stages of development in the rat and find that Nurr1 expression first appears as an elongated line along the anterior-posterior axis on embryonic day 13.5 (E13.5) and then gradually differentiates into multiple sub-regions during prenatal development. Previous birth dating studies of the claustrum have led to conflicting results, therefore, we combine 5-ethynyl-2′-deoxyuridine (EdU) labeling with in situ hybridization for Nurr1 to study birth dating patterns. We find that most dorsal endopiriform (DEn) neurons are born on E13.5 to E14.5. Ventral claustrum (vCL) and dorsal claustrum (dCL) are mainly born on E14.5 to E15.5. Nurr1 positive cortical deep layer neurons (dLn) and superficial layer neurons (sLn) are mainly born on E14.5 to E15.5 and E15.5 to E17.5, respectively. Finally, we identify ventral to dorsal and posterior to anterior neurogenetic gradients within vCL and DEn. Thus, our findings suggest that claustrum and Nurr1 positive neurons in the lateral cortex are born sequentially over several days of embryonic development and contribute toward charting the complex developmental pattern of the claustrum in rodents.

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The Superior Glenohumeral Joint Capsule Alone Does Not Prevent Superior Translation of the Humeral Head: An In Vitro Biomechanical Study

Arthroscopy The Journal of Arthroscopic and Related Surgery ◽

10.1016/j.arthro.2018.06.025 ◽

2018 ◽

Vol 34 (11) ◽

pp. 2962-2970 ◽

Cited By ~ 7

Author(s):

Qingxiang Hu ◽

Zhenyu Ding ◽

Haoyu Zhang ◽

Yaohua He

Keyword(s):

Humeral Head ◽

Glenohumeral Joint ◽

Biomechanical Study ◽

Joint Capsule

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The influence of posterior glenohumeral joint capsule tightness and humeral retroversion on clinical measurements

Physical Therapy in Sport ◽

10.1016/j.ptsp.2018.10.003 ◽

2018 ◽

Vol 34 ◽

pp. 148-153 ◽

Cited By ~ 1

Author(s):

Dayana P. Rosa ◽

Paula R. Camargo ◽

John D. Borstad

Keyword(s):

Glenohumeral Joint ◽

Joint Capsule ◽

Humeral Retroversion ◽

Clinical Measurements

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Body Weight Effects on Extra-Osseous Subtalar Arthroereisis

Journal of Clinical Medicine ◽

10.3390/jcm8091273 ◽

2019 ◽

Vol 8 (9) ◽

pp. 1273 ◽

Cited By ~ 2

Author(s):

Chiun-Hua Hsieh ◽

Chia-Che Lee ◽

Tzu-Hao Tseng ◽

Kuan-Wen Wu ◽

Jia-Feng Chang ◽

...

Keyword(s):

Body Weight ◽

Lateral View ◽

The Body ◽

Posterior View ◽

Flexible Flatfoot ◽

Subtalar Arthroereisis ◽

Overweight Group ◽

Anterior Posterior

Implant extrusion in subtalar arthroereisis is a common complication for pediatric flexible flatfoot. However, there were a limited number of articles addressing the body weight effects on implant extrusion after the procedure. We conducted a 24-month follow-up assessment after subtalar arthroereisis. Surgical patients who underwent the Vulpius procedure were retrospectively collected from May 2010 to January 2017, including 59 cases of both feet having implants in situ and 43 cases of both feet having implant extrusion. The average age of 102 patients was 9 years old. The mean body mass index (BMI) of the implant in situ group was 19.5, whilst the extrusion group was 21.2 (p = 0.035). The inter-observer correlation was excellent. There were 11 cases (39.3%) of bilateral extrusion in the overweight group (BMI ≥ 24) and 13 cases (23.2%) in the low body weight group (BMI ≤ 18.5) (p < 0.0004). Postoperative radiographic angles were corrected in both the implant in situ group and the extrusion group. Nonetheless, the implant in situ group revealed better postoperative outcomes of Meary’s angle and the talonavicular angle from an anterior-posterior view, and the talar inclination angle from a lateral view. We conclude that a higher BMI is related to implant extrusion and worse results after subtalar arthroereisis. Further prospective study to investigate whether preoperative weight loss results in improved surgical outcomes is warranted in the future.

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