Grip Force Research Articles

Compound Z526 alleviates chemotherapy-induced cachectic muscle loss by ameliorating oxidative stress-driven protein metabolic imbalance and apoptosis

Chemotherapy is one of the primary and indispensable intervention against cancers though it is always accompanied by severe side effects especially cachexia. Cachexia is a fatal metabolic disorder syndrome, mainly characterized by muscle loss. Oxidative stress is the key factor that trigger cachectic muscle loss by inducing imbalance in protein metabolism and apoptosis. Here, we showed an oral compound (Z526) exhibited potent alleviating effects on C2C12 myotube atrophy induced by various chemotherapeutic agents in vitro as well as mice muscle loss and impaired grip force induced by oxaliplatin in vivo. Furthermore, Z526 also could ameliorate C2C12 myotube atrophy induced by the combination of chemotherapeutic agents with conditioned medium of various tumor cells in vitro as well as mice muscle atrophy of C26 tumor-bearing mice treated with oxaliplatin. The pharmacological effects of Z526 were based on its potency in reducing oxidative stress in cachectic myocytes and muscle tissues, which inhibited the activation of NF-κB and STAT3 to decrease Atrogin-1-mediated protein degradation, activated the AKT/mTOR signaling pathway to promote protein synthesis, regulated Bcl-2/BAX ratio to reduce Caspase-3-triggered apoptosis. Our work suggested Z526 to be an optional strategy for ameliorating cachexia muscle atrophy in the multimodality treatment of cancers.

Design and Assessment of Bird-Inspired 3D-Printed Models to Evaluate Grasp Mechanics.

Adapting grasp-specialized biomechanical structures into current research with 3D-printed prostheses may improve robotic dexterity in grasping a wider variety of objects. Claw variations across various bird species lend biomechanical advantages for grasping motions related to perching, climbing, and hunting. Designs inspired by bird claws provide improvements beyond a human-inspired structure for specific grasping applications to offer a solution for mitigating a cause of the high rejection rate for upper-limb prostheses. This research focuses on the design and manufacturing of two robotic test devices with different toe arrangements. The first, anisodactyl (three toes at the front, one at the back), is commonly found in birds of prey such as falcons and hawks. The second, zygodactyl (two toes at the front, two at the back), is commonly found in climbing birds such as woodpeckers and parrots. The evaluation methods for these models included a qualitative variable-object grasp assessment. The results highlighted design features that suggest an improved grasp: a small and central palm, curved distal digit components, and a symmetrical digit arrangement. A quantitative grip force test demonstrated that the single digit, the anisodactyl claw, and the zygodactyl claw designs support loads up to 64.3 N, 86.1 N, and 74.1 N, respectively. These loads exceed the minimum mechanical load capabilities for prosthetic devices. The developed designs offer insights into how biomimicry can be harnessed to optimize the grasping functionality of upper-limb prostheses.

Effect of Exercises for Strengthening the Intrinsic Muscles of the Foot and Improving Ankle Mobility on Patients of Diabetic Peripheral Neuropathy.

Background and objectives The study aimed to compare the efficacy of standard home care versus structured ankle mobility exercises in enhancing ankle and foot joint range of motion (ROM) among individuals with diabetes mellitus (DM). Additionally, it investigated the impact of foot intrinsic muscle strengthening exercises on hallux grip force in those with Diabetic Peripheral Neuropathy (DN). Materials and methods In a study of 200 patients with Diabetic Neuropathy (DN), selected from 345 screened diabetics with stable glucose levels and routine monitoring at a tertiary care facility, the efficacy of structured exercises versus standard care was evaluated. Participants, aged 40-70 years with mild neuropathic symptoms (neuropathy disability score of 3 to 5), were divided into two groups. Group 1 received standard care per International Diabetic Foot guidelines, while Group 2 performed targeted foot intrinsic muscle strengthening and ankle mobility exercises over eight weeks. The range of motion (ROM) for ankle and first metatarsophalangeal (MTP) joints and hallux grip force were measured, showing significant improvements in Group 2. Analysis was done using IBM SPSS. Results The average age of the individuals in group 1 (n=100) was 53.87±5.42 years, whereas the average age of the subjects in group 2 (n=100) was 54.23±4.69 years. The study included a total of 97 male participants, with 48 in group 1 and 49 in group 2. The groups exhibited homogeneity in terms of age, gender, duration of DM, and BMI (p>,0.05). When comparing the ROM for ankle dorsiflexion between the groups, it was shown that subjects in group 2 had a substantially higher ROM following exercise for both the right (27.97°±5.3° Vs 19.24°±2.54°) and left (28.55°±4.61° Vs 18.22°±1.14°) ankles compared to the patients in group 1 (p<,0.01). Nevertheless, there were statistically insignificant differences (p>,0.05) observed within the groups, both before and after the exercises, for all the variables examined except for right and left ankle dorsiflexion, and right ankle plantarflexion in group 2. Group 2 subjects exhibited a considerably greater hallux grip force compared to group 1 subjects. The mean enhanced paper grip strength for the right and left big toe of group 2 was 44±3.58 N and 43.2±2.62 N respectively. The mean enhanced paper grip force for the right and left big toe of group 1 was 38±3.11 N and 37.92±2.13 N respectively. A statistically highly significant difference was observed for hallux grip force between the groups (p<,0.01). Conclusion The findings of this study suggest that performing the foot intrinsic muscle strengthening and ankle mobility exercises on the foot and ankle joints can potentially enhance ROM and hallux grip force in patient groups with DN.

Unveiling the invisible: receivers use object weight cues for grip force planning in handover actions

Handover actions are part of our daily lives. Whether it is the milk carton at the breakfast table or tickets at the box office, we usually perform these joint actions without much conscious attention. The individual actions involved in handovers, that have already been studied intensively at the level of individual actions, are grasping, lifting, and transporting objects. Depending on the object’s properties, actors must plan their execution in order to ensure smooth and efficient object transfer. Therefore, anticipatory grip force scaling is crucial. Grip forces are planned in anticipation using weight estimates based on experience or visual cues. This study aimed to investigate whether receivers are able to correctly estimate object weight by observing the giver’s kinematics. For this purpose, handover actions were performed with 20 dyads, manipulating the participant role (giver/receiver) and varying the size and weight of the object. Due to the random presentation of the object weight and the absence of visual cues, the participants were unaware of the object weight from trial to trial. Kinematics were recorded with a motion tracking system and grip forces were recorded with customized test objects. Peak grip force rates were used as a measure of anticipated object weight. Results showed that receiver kinematics are significantly affected by object weight. The peak grip force rates showed that receivers anticipate object weight, but givers not. This supports the hypothesis that receivers obtain information about the object weight by observing giver’s kinematics and integrating this information into their own action execution.

The impact of task (un)certainty on repeated grip force production

Many studies found that in physical tasks, reducing certainty regarding their endpoints hinders performance. However, the impact of reducing certainty regarding other aspects of physical tasks is unknown. Here we manipulated the certainty of the required effort on an unrelated, parallel task (i.e., off-task uncertainty) and examined how it impacts force production in two within-subject experiments (N = 79). In two sessions, subjects completed 20 repetitions composed of maximal forces using a gripper with their dominant hand. Between repetitions, participants applied either submaximal constant or varied grip forces, with their non-dominant arm, matched for total forces across repetitions. While we observed trivial differences in total forces between conditions, under the varied condition, participants produced a steeper decrease in forces, suggesting that off-task uncertainty impacted their effort allocation strategy. We speculate that this pattern can be attributed to cognitive overload and/or changes in motivation stemming from the imposed uncertainty.

Comparative study on dynamic responses of integrated installation process of a 5-MW and a 15-MW offshore wind turbine considering a pre-installed foundation

The integrated installation method for offshore wind turbines has the characteristics of high efficiency and low economic cost due to the small amount of construction work. However, the complexity of the entire system is exacerbated by environmental loads and mechanical couplings. Hence, it is urgent to investigate the dynamic response of OWTs during integrated installation procedures. This work compares the dynamic responses between NREL 5 MW and IEA 15 MW OWT installation systems. The hydrodynamics are calculated using the potential flow theory and the Morison equation, while the aerodynamics under wind turbine parked conditions are computed using the blade element momentum theory. Time domain simulations, considering various wind and wave conditions, are conducted via SIMA. This paper discusses the effects of wind and wave loads on the motion responses of catamaran installation vessel and spar, the relative motion at the mating point, and the sliding gripper forces, respectively. The results reveal that both the surge motions of the catamaran and the spar and the pitch motion of the spar exhibit sensitivity to wind loads. During installation, the motion response of the IEA 15 MW model is more dramatic than that of the NREL 5 MW system. Under wave-only conditions, the radial distances of the mating points for both NREL 5 MW and IEA 15 MW systems reach 1.65 m and 2.51 m, respectively. However, the influences of wind loads and wave incident angle are limited.

Relative contribution of sensory and motor deficits on grip force control in patients with chronic stroke

ObjectiveThis study aimed to characterize grasping behavior in static (weight-dependent modulation and stability of control) and dynamic (predictive control) aspects specifically focusing on the relative contribution of sensory and motor deficits to grip force control in patients with chronic stroke. MethodsTwenty-four chronic stroke patients performed three manipulative tasks: five trials of 5-s grasp-lift-holding, 30-s static holding, and vertical dynamic/cyclic oscillation of holding the object. ResultsExerted static grip force on the paretic side exhibited statistically greater than that on the non-paretic side. Spearman's rank correlation coefficient revealed that the contribution to static grip force control was larger in sensory deficits than in motor deficits. In addition, the sensory deficit is related to the reduced coupling between grip force and load force, suggesting difficulty in predictive control due to the absence of sensory feedback. ConclusionsGiven that grip force control involves predictive feedforward and online feedback control, the evaluation of grip force might be an important and feasible evaluation manner for the assessment of sensorimotor control in patients post-stroke. SignificanceDetailed evaluation of grip force control would help to understand the mechanisms underlying hand dysfunction in stroke patients.

Cortical Sensorimotor Integration as a Neural Origin of Impaired Grip Force Direction Control following Stroke.

Stroke is a major cause of disability worldwide. Upper limb impairment is prevalent after stroke. One of the post-stroke manifestations is impaired grip force directional control contributing to diminished abilities to grip and manipulate objects necessary for activities of daily living. The objective of this study was to investigate the neural origin of the impaired grip force direction control following stroke. Due to the importance of online adjustment of motor output based on sensory feedback, it was hypothesized that grip force direction control would be associated with cortical sensorimotor integration in stroke survivors. Ten chronic stroke survivors participated in this study. Cortical sensorimotor integration was quantified by short latency afferent inhibition (SAI), which represents the responsiveness of the primary motor cortex to somatosensory input. Grip force direction control was assessed during paretic grip. Grip force direction control was significantly associated with SAI. This relationship was independent of sensory impairment level. Cortical sensorimotor integration may play a significant role in the grip force direction control important for gripping and manipulating objects with the affected hand following stroke. This knowledge may be used to inform personalized rehabilitation treatment. For example, for patients with impaired grip force direction control, behavioral therapy focusing on feedback motor control, augmented by use of brain stimulation to reinforce cortical sensorimotor integration such as paired associative stimulation, may be applied.

Longitudinal changes in body composition, physiological characteristics, and motor performance of Paralympic goalball athletes

Research has yet to explore the long-term influences of physical fitness parameters on goalball and how COVID-19 affected athletes’ training program. This study evaluated the longitudinal changes in body composition (BC), postural balance (PB), maximal isometric grip force (MIGF), vertical jump (countermovement (CJ), squat jump (SJ), and peak oxygen consumption (VO2peak) in seven male Paralympic goalball athletes preparing for the Tokyo 2020 Paralympics. Six measurements were performed three times ([first] pre-lock down: January 2020, [second] post-lock down: September 2020, and [third] final follow-up: June 2021) on a variable-by-variable basis. Post hoc tests showed a significant improvement in BC at the third time point compared to the first and second time points. Concomitantly, PB and MIGF were significantly improved at the third time point compared to the first and second time points, respectively. A significant decline was observed in CJ and SJ heights at the second time point compared to the first time point whereas SJ height increased at the third time point compared to the second time point. No change was observed in CJ height at the third time point versus the second time point. There was a dramatic reduction in VO2peak at the second time point compared to the first time point. No change was observed in VO2peak occurred at the third time point versus pre and post lock down. Even with the disruption in the annual training plan due to COVID-19 pandemic, our participants maintained physical fitness levels with home-based exercises.

Branching out: perch diameter and orientation affect pull strength in chameleons (genus: Bradypodion)

Abstract Arboreal species tend to have specific adaptations allowing them to effectively negotiate the complexity of their habitats. For example, chameleons have a prehensile tail and limbs adapted to grasping branches. However, the impact of branch diameter and orientation on their movement has been poorly studied. Using ecological, morphological, and pull force data from two species of Bradypodion from different habitats, we examined if chameleons use different substrates and if perch orientation and diameter affect pull strength by quantifying their grip forces on different sized dowels. We found that the habitat of Bradypodion ventrale is homogeneous, and dominated by sparse patches of narrow, vertical perches. For this species, perch diameter significantly affected pull strength in both horizontal and vertical pull directions, with chameleons performing best on a vertical 1.5-mm dowel and a horizontal 3-mm dowel. In contrast, Bradypodion pumilum typically occurs in more variable vegetation, ranging from low shrubs to wooded habitat with high canopy. Our results show that the habitat has perches that are on average wider than for B. ventrale with a greater size range. The performance of B. pumilum was less impacted by perch diameter and pull direction suggesting that B. pumilum is able to use perches of different diameters in their more heterogeneous habitat.

Advancing Robotic Gripper Control with the Integration of Flexible Printed Pressure Sensors

A pressure sensor array fabricated on a flexible substrate using the printing method can be easily mounted in various locations by combining it with a wireless communication circuit. This is particularly advantageous for applications where wiring is difficult, such as the tip of a robot gripper. Additionally, printed devices are highly efficient in material utilization, facilitating large areas and low‐cost production. In recent years, there has been growing interest in the harmonious interaction between robots and humans, and the intelligentization of robots is a worthwhile research area. Herein, a method for realizing intelligent gripping force control and object recognition robots using a printed flexible pressure sensor array in combination with a wireless communication circuit is proposed. By mounting the sensor array on a robot gripper and performing arithmetic processing on software, these capabilities are achieved.

The interplay of sensory feedback, arousal, and action tremor amplitude in essential tremor.

Essential tremor (ET) amplitude is modulated by visual feedback during target driven movements and in a grip force task. It has not been examined yet whether visual feedback exclusively modulates target force tremor amplitude or if other afferent inputs like auditory sensation has a modulatory effect on tremor amplitude as well. Also, it is unknown whether the enhanced sensory feedback causes an increase of arousal in persons with ET (p-ET). We hypothesized that (1) amplitude of tremor is modulated by variation of auditory feedback in the absence of visual feedback in a force tremor paradigm; (2) increase of tremor amplitude coincides with pupillary size as a measure of arousal. 14 p-ET and 14 matched healthy controls (HC) conducted a computer-based experiment in which they were asked to match a target force on a force sensor using their thumb and index finger. The force-induced movement was fed back to the participant visually, auditory or by a combination of both. Results showed a comparable deviation from the target force (RMSE) during the experiment during all three sensory feedback modalities. The ANOVA revealed an effect of the high vs. low feedback condition on the tremor severity (Power 4-12Hz) for the visual- and also for the auditory feedback condition in p-ET. Pupillometry showed a significantly increased pupil diameter during the auditory involved high feedback conditions compared to the low feedback conditions in p-ET. Our findings suggest that action tremor in ET is firstly modulated not only by visual feedback but also by auditory feedback in a comparable manner. Therefore, tremor modulation seems to be modality independent. Secondly, high feedback was associated with a significant pupil dilation, possibly mirroring an increased arousal/perceived effort.

An intelligent grasper to provide real-time force feedback to shorten the learning curve in laparoscopic training

BackgroundA lack of force feedback in laparoscopic surgery often leads to a steep learning curve to the novices and traditional training system equipped with force feedback need a high educational cost. This study aimed to use a laparoscopic grasper providing force feedback in laparoscopic training which can assist in controlling of gripping forces and improve the learning processing of the novices.MethodsFirstly, we conducted a pre-experiment to verify the role of force feedback in gripping operations and establish the safe gripping force threshold for the tasks. Following this, we proceeded with a four-week training program. Unlike the novices without feedback (Group A2), the novices receiving feedback (Group B2) underwent training that included force feedback. Finally, we completed a follow-up period without providing force feedback to assess the training effect under different conditions. Real-time force parameters were recorded and compared.ResultsIn the pre-experiment, we set the gripping force threshold for the tasks based on the experienced surgeons’ performance. This is reasonable as the experienced surgeons have obtained adequate skill of handling grasper. The thresholds for task 1, 2, and 3 were set as 0.731 N, 1.203 N and 0.938 N, respectively. With force feedback, the gripping force applied by the novices with feedback (Group B1) was lower than that of the novices without feedback (Group A1) (p < 0.005). During the training period, the Group B2 takes 6 trails to achieve gripping force of 0.635 N, which is lower than the threshold line, whereas the Group A2 needs 11 trails, meaning that the learning curve of Group B2 was significantly shorter than that of Group A2. Additionally, during the follow-up period, there was no significant decline in force learning, and Group B2 demonstrated better control of gripping operations. The training with force feedback received positive evaluations.ConclusionOur study shows that using a grasper providing force feedback in laparoscopic training can help to control the gripping force and shorten the learning curve. It is anticipated that the laparoscopic grasper equipped with FBG sensor is promising to provide force feedback during laparoscopic training, which ultimately shows great potential in laparoscopic surgery.

High-intensity acute exercise impacts motor learning in healthy older adults

Healthy aging is associated with changes in motor sequence learning, with some studies indicating decline in motor skill learning in older age. Acute cardiorespiratory exercise has emerged as a potential intervention to improve motor learning, however research in healthy older adults is limited. The current study investigated the impact of high-intensity interval exercise (HIIT) on a subsequent sequential motor learning task. Twenty-four older adults (aged 55–75 years) completed either 20-minutes of cycling, or an equivalent period of active rest before practicing a sequential force grip task. Skill learning was assessed during acquisition and at a 6-hour retention test. In contrast to expectation, exercise was associated with reduced accuracy during skill acquisition compared to rest, particularly for the oldest participants. However, improvements in motor skill were retained in the exercise condition, while a reduction in skill was observed following rest. Our findings indicate that high-intensity exercise conducted immediately prior to learning a novel motor skill may have a negative impact on motor performance during learning in older adults. We also demonstrated that exercise may facilitate early offline consolidation of a motor skill within this population, which has implications for motor rehabilitation.

Development of a new cerebral ischemia reperfusion model of Mongolian gerbils and standardized evaluation system.

The Mongolian gerbil is an excellent laboratory animal for preparing the cerebral ischemia model due to its inherent deficiency in the circle of Willis. However, the low incidence and unpredictability of symptoms are caused by numerous complex variant types of the circle. Additionally, the lack of an evaluation system for the cerebral ischemia/reperfusion (I/R) model of gerbils has shackled the application of this model. We created a symptom-oriented principle and detailed neurobehavioral scoring criteria. At different time points of reperfusion, we analyzed the alteration in locomotion by rotarod test and grip force score, infarct volume by triphenyltetrazolium chloride (TTC) staining, neuron loss using Nissl staining, and histological characteristics using hematoxylin-eosin (H&E) straining. With a successful model rate of 56%, 32 of the 57 gerbils operated by our method harbored typical features of cerebral I/R injury, and the mortality rate in the male gerbils was significantly higher than that in the female gerbils. The successfully prepared I/R gerbils demonstrated a significant reduction in motility and grip strength at 1 day after reperfusion; formed obvious infarction; exhibited typical pathological features, such as tissue edema, neuronal atrophy and death, and vacuolated structures; and were partially recovered with the extension of reperfusion time. This study developed a new method for the unilateral common carotid artery ligation I/R model of gerbil and established a standardized evaluation system for this model, which could provide a new cerebral I/R model of gerbils with more practical applications.

Effect of Kinesio taping on wrist proprioception in healthy subjects: A randomized clinical trial

BackgroundAlthough the use of KT has increased considerably in the clinical practice in the last years, there is limited evidence about the effects of its application in proprioception. PurposeThe aim of this study was to determine the effect of KT on joint position sense and force sense on the wrist of healthy subjects. MethodsFifty-four subjects were analyzed in a randomized, crossover, single-blind study design. To determine the force sense, the subjects had to reach 50% of their maximum grip force. Wrist joint position sense was assessed during active repositioning tests at the target angles of 30° flexion and extension of wrist. A digital dynamometer was used to determine the sense of force and a digital goniometer was used to determine the joint position sense. Subjects were evaluated with KT (I- strip on ventral aspect of forearms from origin to insertion) and placebo (an inelastic tape was applied following the same procedure as KT). ResultsNo significant differences have been found in the force sense, neither in the comparisons between control and interventions (p=0.286), nor between pre and post-intervention (p=0.111). For wrist joint position sense, a statistically significant effect (p< 0.05) was found at 30º of extension between the control and experimental group in favor of the control group. ConclusionsThe application of KT did not produce changes in FS and only caused a significant improvement in JPS in extension (30º). The results appear to indicate that the application of KT to improve proprioception in healthy subjects should be reconsidered.

Design of Household Cognitive Level Assessment System Based on Grip Force and Finger Force Distribution.

In this paper we designed a household cognitive level assessment system based on finger force distribution. The system evaluates the user's current cognitive level according to the degree of matching between the characteristics of user's grip force and finger force distribution data and the characteristics in the database. The system based on finger force distribution will greatly reduce the space and economic cost of household cognitive level assessment.

Older adults are impaired in the release of grip force during a force tracking task.

Age-related changes in force generation have been implicated in declines in older adult manual dexterity. While force generation is a critical aspect of the successful manipulation of objects, the controlled release of force represents the final component of dexterous activities. The impact of advancing age on the release of grip force has received relatively little investigation despite its importance in dexterity. The primary aim of this project was to determine the effects of age on the control of force release during a precision grip tracking task. Young adults (N = 10, 18-28years) and older adults (N = 10, 57-77years) completed a ramp-hold-release (0-35% of maximum grip force) force tracking task with their dominant hand. Compared to young adults, older adults were disproportionately less accurate (i.e., less time within target range) and had more error (i.e., greater relative root mean squared error) in the release of force, compared to generation of grip force. There was a significant difference between groups in two-point discrimination of the thumb, which was moderately correlated to force control across all phases of the task. The decline in force release performance associated with advanced age may be a result of sensory deficits and changes in central nervous system circuitry.

Fast grip force adaptation to friction relies on localized fingerpad strains.

During object manipulation, humans adjust the grip force to friction, such that slippery objects are squeezed more firmly than sticky ones. This essential mechanism to keep a stable grasp relies on feedback from tactile afferents innervating the fingertips, that are sensitive to local skin strains. To test if this feedback originates from the skin-object interface, we asked participants to perform a grip-lift task with an instrumented object able to monitor skin strains at the contact through transparent plates of different frictions. We observed that, following an unbeknown change in plate across trials, participants adapted their grip force to friction. After switching from high to low friction, we found a significant increase in strain inside the contact arising ~100 ms before the modulation of grip force, suggesting that differences in strain patterns before lift-off are used by the nervous system to quickly adjust the force to the frictional properties of manipulated objects.

Towards hand grip force assessment by using EMG estimators

The purpose of this study was to propose a method to assess individual regression (calibration) curves to establish a relationship between an isometric grip force and surface electromyography (EMG) estimator. In this study 18 healthy volunteers (12 male (23.0 ± 2.0 years) and 6 female (23.2 ± 0.7 years)) had been examined. Ten EMG estimators (mean absolute value, root mean square, entropy, energy, turns per second, mean of zero crossings, median power frequency, mean power frequency, and Hilbert transforms), two EMG locations (brachioradialis and flexor digitorum superficialis) and five types of regression curves (linear, exponential, power, logarithm, and quadratic polynomial) have been tested. Using a quadratic polynomial regression curve and energy EMG estimator of the flexor digitorum superficialis muscle, it was obtained the lowest dispersity of EMG estimator and the most accurate prediction of grip isometric force among all tested EMG estimators.