Grip Type Research Articles

Influence of Mouse Grip Type on Flicking and Tracking Tasks Performance

Influence of Mouse Grip Type on Flicking and Tracking Tasks Performance

탄성 밴드를 활용한 스탠딩 로우 운동의 그립 형태가 주동근과 안정근의 근활성도에 미치는 영향

This study aimed to investigate the effect of standing row exercise grip on the muscle activity of agonist and stabilizer muscles. 9 men with at least 6 months of resistance exercise experience were selected and performed standing row exercise using an elastic band with a tension of 12 kg. Electromyography was measured during 10 standing row movements according to three types of grips (over, parallel, under), and the muscles of the biceps brachii, rectus abdominis, erector spinae, upper trapezius, middle trapezius, lower trapezius, and latissimus dorsi muscles were measured. The hair roots and latissimus dorsi muscles were measured. For data processing, repeated measures one-way analysis of variance was performed using the SPSS ver 22.0 statistical program. In the biceps brachii, there was a significant difference in the electromyographic response depending on the grip type, and it was highest in the undergrip. Significant differences were also seen in the upper trapezius and middle trapezius muscles, and were highest in the overgrip. This conclusion suggests that due to changes in activated muscles depending on the grip type, the grip type and arm angle should be considered according to the target muscle development when creating a program for row exercise.

Sensory Factors Influence Dynamic and Static Bi-Manual Finger Grip Strength in a Real-World Task Context

Individual grip strength provides a functional window into somatosensory processes and their effects on motor behaviour in healthy, impaired, and ageing individuals. Variations in grip strength during hand–tool interaction are therefore exploited in a variety of experimental tasks to study the effects of pathology or ageing-related changes on sensory, motor, and cognitive ability. However, many different factors may influence individual grip strength systematically in a given task context without being explicitly identified and controlled for. Grip strength may vary as a function of the location of the measurement device (sensor) on the fingers/hand, the shape, weight and size of object(s) being gripped, the type of grip investigated (static versus dynamic grip), and the hand (dominant versus non-dominant) used for gripping. This study tests for additional factors such as sight, sound, and interactions with/between any of the other factors in a complex task context. A wearable biosensor system, designed for measuring grip strength variations in operators gripping cylindrical objects bi-manually, was used. Grip force signals were recorded from all sensors of the wearable (glove) system, including three directly task-relevant sensors for bi-manually gripping cylindrical objects with the dominant and non-dominant hands. Five young male participants were tested for the effects of sound, movement, and sight on grip strength. The participants had to pick up two cylindrical objects of identical size and weight, then hold them still (static grip) or move them upwards and downwards (dynamic grip) for ten seconds while listening to soft or hard music, with their eyes open or blindfolded. Significant effects of sensor location, hand, movement, sight, and sound on bi-manual grip strength were found. Stronger grip force signals were produced by task-relevant sensors in the dominant hand when moving the cylindrical handles (dynamic grip) in comparison with the static grip condition, depending, as expected, on whether grip signals were measured from the dominant or the non-dominant hand. Significantly stronger grip strength was produced blindfolded (sight condition), and grips were significantly stronger with exposure to harder music (sound factor). It is concluded that grip strength is significantly influenced by sensory factors and interactions between the other factors tested for, pointing towards the need for identifying and systematically controlling such potential sources of variation in complex study task contexts.

Sound symbolism in manual and vocal responses: phoneme-response interactions associated with grasping as well as vertical and size dimensions of keypresses

It has been shown that reading the vowel [i] and consonant [t] facilitates precision grip responses, while [ɑ] and [k] are associated with faster power grip responses. A similar effect has been observed when participants perform responses with small or large response keys. The present study investigated whether the vowels and consonants could produce different effects with the grip responses and keypresses when the speech units are read aloud (Experiment 1) or silently (Experiment 2). As a second objective, the study investigated whether the recently observed effect, in which the upper position of a visual stimulus is associated with faster vocalizations of the high vowel and the lower position is associated with the low vowel, can be observed in manual responses linking, for example, the [i] with responses of the upper key and [ɑ] with lower responses. Firstly, the study showed that when the consonants are overtly articulated, the interaction effect can be observed only with the grip responses, while the vowel production was shown to systematically influence small/large keypresses, as well as precision/power grip responses. Secondly, the vowel [i] and consonant [t] were associated with the upper responses, while [ɑ] and [k] were associated with the lower responses, particularly in the overt articulation task. The paper delves into the potential sound-symbolic implications of these phonetic elements, suggesting that their acoustic and articulatory characteristics might implicitly align them with specific response magnitudes, vertical positions, and grip types.

Influence of food physical properties and environmental context on manipulative behaviors highlighted by new methodological approaches in zoo-housed bonobos (Pan paniscus).

Research on manipulative abilities in nonhuman primates, in the context of hominid evolution, has mostly focused on manual/pedal postures considered as static behaviors. While these behavioral repertoires highlighted the range of manipulative abilities in many species, manipulation is a dynamic process that mostly involves successive types of grips before reaching its goal. The present study aims to investigate the use of manual/pedal postures in zoo-housed bonobos in diverse dynamic food processing by using an innovative approach: the optimal matching analysis that compares sequences (i.e., succession of grasping postures) with each other. To characterize the manipulative techniques spontaneously employed by bonobos, we performed this sequential analysis of manual/pedal postures during 766 complete feeding sequences of 17 individuals. We analyzed the effectiveness with a score defined by a partial proxy of food intake (i.e., the number of mouthfuls) linked to a handling score measuring both the diversity and changes of manual postures during each sequence. We identified four techniques, used differently depending on the physical substrate on which the individual performed food manipulation and the food physical properties. Our results showed that manipulative techniques were more complex (i.e., higher handling score) for large foods and on substrates with lower stability. But the effectiveness score was not significantly lower for these items since manipulative complexity seemed to be compensated by a greater number of mouthfuls. It appeared that the techniques employed involved a trade-off between manipulative complexity and the amount of food ingested. This study allowed us to test and validate innovative analysis methods that are applicable to diverse ethological studies involving sequential events. Our results bring new data for a better understanding of the evolution of manual abilities in primates in association with different ecological contexts and both terrestrial and arboreal substrates and suggest that social and individual influences need to be explored further.

Mu-ERD reflects action understanding, but the effect is small

Since the mid-2000’s, many researchers have provided evidence that mu-ERD measured at the motor cortex may reflect the collective activation of upstream brain regions associated with the human mirror system during action observation paradigms; however, several recent papers have called these findings into question. Our study represents an effort to address these criticisms. In our study, participants watched videos in which the type of grip an actor used to grasp a coffee mug either conveyed the goal with 100 % certainty (unambiguous-goal trials), or offered no predictive information (ambiguous-goal trials). If mu-ERD indexes action understanding, then we predicted that mu-ERD should increase while participants watched the actor grasp the mug for unambiguous-goal trials, but not for ambiguous-goal trials. During the intervals where participants watched the actor execute the goal, mu-ERD for unambiguous-goal trials should remain steady, whereas mu-ERD for ambiguous-goal trials should now increase. Conversely, if mu-ERD does not index action understanding, and instead reflects general motor processes associated with action (such as the activation of population vectors in M1 or planning processes), then mu-ERD should show no difference across conditions. Across most comparisons, we found that mu-ERD mostly reflected general motor processes; however, there was a small effect when participants overserved unambiguous-goal trials while watching the actor execute the goal suggesting that mu-ERD does reflect mirroring, but the effect is small.

Bilateral reconstruction of palmar soft tissues defects of the hands after thermal injury

Introduction Thermal injury to the palmar surface of the hand is usually complicated by flexion desmogenic contracture of the finger joints. This condition is more complicated with significant wound areas and depths of soft tissue destruction. Conventional surgical methods and soft tissue reconstructions may fail to provide full restoration of the hand function.The objective was to present the optimal treatment strategy for patients with scar flexion contractures of the fingers after thermal injury to the palmar surface of both hands using a pediatric case report.Material and methods A child aged 2 years and 4 months underwent surgical treatment to include excision of scars, skin grafting of both hands with a vascularized fasciocutaneous flap raised with the radial artery.Result The patient could regain all types of hand grip on both sides 12 years after surgical treatment. Both hands were aesthetically acceptable.Discussion Treatment of patients with thermal injury and substantial soft tissue damage is a complex disease process. Conservative treatment and surgical procedures using non-vascularized skin flaps are normally used for the condition. These approaches are associated with cicatricial and arthrogenic flexion contracture of the finger joints. The radical treatment includes thorough wound debridement and early flap coverage and wound closure using a flap with an axial-pattern blood supply, free flaps and reverse-flow flaps. The surgical approach helps to avoid flexion contracture of the fingers initiating early restoration of professional, social stereotypes and stereotypes in everyday life.Conclusion The clinical observation has shown the possibility of one-stage organ-preserving surgical treatment using flaps with an axial blood supply.

Convolutional neural networks reveal properties of reach-to-grasp encoding in posterior parietal cortex

Deep neural networks (DNNs) are widely adopted to decode motor states from both non-invasively and invasively recorded neural signals, e.g., for realizing brain-computer interfaces. However, the neurophysiological interpretation of how DNNs make the decision based on the input neural activity is limitedly addressed, especially when applied to invasively recorded data. This reduces decoder reliability and transparency, and prevents the exploitation of decoders to better comprehend motor neural encoding. Here, we adopted an explainable artificial intelligence approach – based on a convolutional neural network and an explanation technique – to reveal spatial and temporal neural properties of reach-to-grasping from single-neuron recordings of the posterior parietal area V6A. The network was able to accurately decode 5 different grip types, and the explanation technique automatically identified the cells and temporal samples that most influenced the network prediction. Grip encoding in V6A neurons already started at movement preparation, peaking during movement execution. A difference was found within V6A: dorsal V6A neurons progressively encoded more for increasingly advanced grips, while ventral V6A neurons for increasingly rudimentary grips, with both subareas following a linear trend between the amount of grip encoding and the level of grip skills. By revealing the elements of the neural activity most relevant for each grip with no a priori assumptions, our approach supports and advances current knowledge about reach-to-grasp encoding in V6A, and it may represent a general tool able to investigate neural correlates of motor or cognitive tasks (e.g., attention and memory tasks) from single-neuron recordings.

Qualitative age-related changes in fine motor skill performance among 3- to 6-year-old typically developing children

This study described intra-task fine motor skill components of the Manual Dexterity tasks (Posting Coins; PC, Threading Beads; TB, Drawing Trail; DT) of the Movement Assessment Battery for Children-2 Test for typically developing children and investigated age- and sex-related differences. Three- to six-year-old Dutch children (n = 182, Mage 4.5 ± 1.1 years, 51.1% boys) were observed with regard to intra-task fine motor skill components, and changes in intra-task components of the Manual Dexterity tasks were analyzed across age using of the Kruskal–Wallis test with post-hoc Mann–Whitney U tests, and differences between sexes using the Mann–Whitney U test. The following intra-task components were observed: grip type, manipulation, non-dominant or non-writing hand, grip position, posture, head, coin placement, placement of the bead on the lace tip and joint movement. Results showed that the younger children (3-year-olds) more frequently used a grasp with the full hand (PC, TB), more often put the coin on the container and sliding it in (PC), more often supported the side or top of the container (PC), used more bi-manual manipulation (transferring from hand-to-hand or hand, body or surface assist) (TB, DT), more frequently used primitive, too high grips, predominantly used their proximal joints, and did not support the paper (DT). This in comparison with more frequent use of three-point pinch, direct coin placement, grabbing the front or back of the container, in-hand-manipulation, mature grips and correct height, distal joint use and supporting the paper from the side or below by most 5- and 6-year-olds. Furthermore, most sex-related differences were found in the younger age-groups (3- and 4-year-olds) in the DT tasks with girls outperforming boys. Results from this study add to the knowledge on qualitative fine motor skill performance in a convenience sample of 3- to 6-year-old typically developing children. A limitation of the current study was the relatively small sample size of 6-year-old children. The strength of the current study is its novelty in providing qualitative descriptions of intra-task fine motor skill components in typically developing 3- to 6-year-old children.

The effects of umbrella handle shape and grip type on muscle activation and postural variability under windy conditions

This study investigated how different shapes of umbrella handles and grip types influence muscle activation and postural variability under windy conditions. Seventeen adult participants were enrolled in this study, and different handle shapes (cylindrical, ellipsoidal, and triangular prism-shaped), grip types (four- and five-finger grip), and wind strengths were tested. Activation of the forearm and upper arm muscles was recorded using surface electromyography. Postural variability and ratings of (1) perceived difficulty of use and (2) perceived grip-posture variability were measured. The results indicated that activation of the finger flexor muscle increased under windy conditions, whereas postural variability was not affected. Weak wind (3.2–7.5 m/s) conditions caused greater perceived postural variability and activation of the wrist extensor muscle. The ellipsoidal handle shape had lower endpoint postural variability when held with a five-finger grip and also had lower perceived postural variability and difficulty compared to that with the cylindrical shape. Our findings can be used to select appropriate umbrella handle designs based on grip type and wind conditions.

The Effects of Structural Characteristics of the Rollator on the Elderly’s Gait Strategies in Various Walking Environments

A rollator, one of the most widely used among walking assistance devices, can assist the elderly with stable walking in their daily lives. In this study, we investigated how the structural characteristics of two types of rollators affect the upper and lower extremity muscle activity and plantar pressure of the elderly in various walking environments. We quantified muscle activity (upper and lower limbs) and plantar pressure (mean force, peak pressure, and contact area) of 11 older adults walking in various environments (flat, obstacle, uneven, and sloped terrain) using two types of rollators. Upper extremity muscle activity was highest in the obstacle terrain and the uneven terrain, and a significant difference was found due to the structural differences of the rollator. Additionally, it was observed that lower extremity muscle activity and plantar pressure patterns appeared in accordance with the gait strategy to maintain stability in an unstable or inclined walking environment. In other words, it was confirmed that the weight of the rollator, the size of the wheel, grip type, and the auxiliary tools had a great effect on the upper and lower extremity muscle activity and plantar pressure of the elderly during walking. From the results of this study, it can be suggested that it is absolutely necessary to consider the biomechanical characteristics of the elderly and the structure of the rollator, which appear differently depending on the walking environment, in the development of walking aids. In the future, more clinical data will be collected, and based on this a rollator that can safely assist the elderly in various walking environments will be developed.

Analysis of grip specificity on force production in grapplers and its effect on bilateral deficit grip specificity and bilateral deficit in force production among grapplers.

The use of strength training is important for athletes in combat sports such as judo and jiu-jitsu. Specificity is key when prescribing strength training programs for athletes, considering maximal strength, muscular power and strength-endurance. Grappling combat sports require grip control, which is necessary to execute throwing techniques and groundwork. The aim of this study was to verify the bilateral strength deficit in general and in grappling combat sport-specific action in the control group and grapplers. A sample of 73 subjects, divided into 2 groups, was used: the Student Group (15 females and 16 males) and the Grappler Group (29 males and 13 females). The male and female participants attended four laboratory sessions over a 48-hour interval, the first two to familiarize themselves with the Electromechanical Functional Dynamometer (EMFD), and the last two to collect maximal isometric strength data, using a standard grip and a judo/jiujitsu specific grip. Significant differences in mean and peak forces (p < 0.001) were found, with high performance combat sport athletes having greater maximal isometric strength compared to students both bilaterally and unilaterally (p < 0.001). All comparisons also indicated higher values for males compared to females (p < 0.001). The results suggest that specific training in combat sports as well as sex differences play a significant role in maximal isometric strength performance. The type of grip used affects the application of force in the upper limb isometric strength tests, finding a main effect of grip type (p < 0.001), with the standard grip obtaining higher levels. However, the dominance between hands remains constant. More research is needed on specific judogi/jiu-jitsu-gi grips and their impact on maximal isometric strength with the EMFD.

ASSESSMENT OF HAND FUNCTION IN PATIENTS WITH RHEUMATOID ARTHRITIS AS A RESULT OF PHYSICAL THERAPY

Assessment of hand function is the great importance in physical therapy for patients with rheumatoid arthritis, as the choice of rehabilitation measures and evaluation of their results depends on the functional capacity of the hand.&#x0D; The purpose is to evaluate hand function in patients with rheumatoid arthritis as a result of physical therapy using the Sollerman test.&#x0D; Materials and methods. The research was conducted on the basis of the rheumatology department and the department of rehabilitation treatment using traditional and alternative methods of the Municipal Enterprise “Rivne Regional Clinical Hospital named after Yuriy Semeniuk” in Rivne. The results of the research were accumulated as patients were admitted for inpatient treatment. A total of 188 patients with rheumatoid arthritis were examined, with an average age of 44.9±7.6 years. All patients were randomly assigned to the control (n=92) and main (n=96) groups. Patients of the control group underwent rehabilitation in accordance with the recommendations of the regulatory document of the Ministry of Health of Ukraine. Patients in the main group were treated according to the proposed physical therapy technology, which included the following elements: therapeutic exercises, therapeutic massage, physiotherapy, hydrotherapy, orthotics, kinesiotaping of the upper extremities, mechanotherapy and psychological support. A physical therapy programme was developed for each patient for a long-term period of 6 months. To determine the function of the arm, the Sollerman test was used. The obtained digital material was processed statistically using the Statistica 10 statistical analysis package (Serial Number: STA999K347150-W).&#x0D; Results. The initial examination revealed the presence of disorders of the basic functions of the hand and deviations from the norm, as well as impaired fine motor skills and various types of hand grip according to the Solleraman test. We analysed the quality of different types of grasping in patients with rheumatoid arthritis, in particular, the greatest difficulties were in performing spherical and cylindrical grasping – in 82.9% of patients and 89.3% of cases, respectively. Forceps grasping was also difficult in 76.5% of patients. During the repeated examination after 3 and 6 months, patients in both groups showed positive dynamics in the performance of individual test tasks. Thus, in patients of the main group, after 3 months, the average Sollerman test scores increased to 65.1±5.3 points, in the control group this figure was significantly lower than 61.8±3.6 points (x ±S) (p&lt;0.05). In 6 months after hospitalisation, the mean values of the Sollerman test in the main group of patients with rheumatoid arthritis increased significantly and were close to normal values. In patients of the control group, the average values of this test also increased, but they were significantly lower than those of the main group. Accordingly, the mean Sollerman test score in patients of the main group increased from 65.1±5.3 points to 70.2±6.3 points, which is significantly higher than in patients of the control group – from 61.8±3.6 points to 65.1±3.8 points (x±S) (p&lt;0.05). The results of the Sollerman test in the main group are significantly higher than those of the control group, which indicates the effectiveness of the developed rehabilitation technology for patients in the main group.&#x0D; Conclusions. The increase in the functional capacity of the upper extremities of patients in the main group with rheumatoid arthritis confirms the effectiveness of the implemented physical therapy technology.

Architecture of the motor and premotor cortex of the capuchin monkey

IntroductionOver the last 65 million years, primates have evolved hind- and forelimbs capable of skilled grasping (e.g., tree branches) and manipulation of tools and other objects. The New World capuchin monkey and the Old World macaque monkey stand out among other primates for their manual dexterity. The capuchin monkey is distributed throughout the Amazon and the Atlantic Forests and is the only New World monkey to have evolved an opposable thumb and to have developed the capability of using tools in the wild.MethodsThe present work analyzes the cyto-, myelo- and immunoarchitecture of the motor and premotor areas of the capuchin monkey using Nissl, Gallyas and SMI-32 immunolabeling techniques.ResultsThese different staining techniques allowed for the parcellation of Brodmann area 4 into the ventral (F1v), medial (F1m) and dorsal (F1d) areas. Additionally, lateral area 6 was subdivided into the dorsal (F2 and F7) and ventral (F4 and F5) areas. Area F5 was subsequently subdivided into the convexity (F5c), anterior (F5a) and posterior (F5p) areas. Medial area 6 was subdivided into F3 and F6 areas.DiscussionThese motor and premotor areas of the capuchin monkey are similar to those of macaque and humans, and different from those of other New World monkeys. We argue that this is due to differences in manual dexterity across New World monkeys: capuchin monkeys have evolved different types of precision grips, while most of the other New World monkeys exclusively perform whole-hand grips during object manipulation.

The effect of the government's green grip: Evidence from government-initiated corporate environmental ratings and corporate debt financing

The Chinese government has initiated corporate environmental ratings to curb environmental pollution. We investigate the impact of such ratings as a type of government green grip on corporate debt consequences. We provide solid evidence that government-initiated corporate environmental ratings help environmentally friendly companies obtain more long-term loans and reduce the cost of debt. Lenders view a healthy environment as a signal of good credit; accordingly, they offer greener companies more favorable debt financing terms. The positive effect of government-initiated corporate environmental ratings is magnified by other government green-credit policies and the external financing environment. Overall, this study provides a valuable understanding of government-initiated corporate environmental ratings and corporate financing consequences.

Motor decoding from the posterior parietal cortex using deep neural networks

Objective. Motor decoding is crucial to translate the neural activity for brain-computer interfaces (BCIs) and provides information on how motor states are encoded in the brain. Deep neural networks (DNNs) are emerging as promising neural decoders. Nevertheless, it is still unclear how different DNNs perform in different motor decoding problems and scenarios, and which network could be a good candidate for invasive BCIs. Approach. Fully-connected, convolutional, and recurrent neural networks (FCNNs, CNNs, RNNs) were designed and applied to decode motor states from neurons recorded from V6A area in the posterior parietal cortex (PPC) of macaques. Three motor tasks were considered, involving reaching and reach-to-grasping (the latter under two illumination conditions). DNNs decoded nine reaching endpoints in 3D space or five grip types using a sliding window approach within the trial course. To evaluate decoders simulating a broad variety of scenarios, the performance was also analyzed while artificially reducing the number of recorded neurons and trials, and while performing transfer learning from one task to another. Finally, the accuracy time course was used to analyze V6A motor encoding. Main results. DNNs outperformed a classic Naïve Bayes classifier, and CNNs additionally outperformed XGBoost and Support Vector Machine classifiers across the motor decoding problems. CNNs resulted the top-performing DNNs when using less neurons and trials, and task-to-task transfer learning improved performance especially in the low data regime. Lastly, V6A neurons encoded reaching and reach-to-grasping properties even from action planning, with the encoding of grip properties occurring later, closer to movement execution, and appearing weaker in darkness. Significance. Results suggest that CNNs are effective candidates to realize neural decoders for invasive BCIs in humans from PPC recordings also reducing BCI calibration times (transfer learning), and that a CNN-based data-driven analysis may provide insights about the encoding properties and the functional roles of brain regions.

Electromyographic Activity of the Pectoralis Major Muscle during Traditional Bench Press and Other Variants of Pectoral Exercises: A Systematic Review and Meta-Analysis

The popularity of the bench press (BP) is justified by being one of the most effective exercises to improve strength and power in the upper body. The primary aim of this systematic review and meta-analysis was to compare the electromyography activity (EMG) of pectoralis muscle between BP and other variants of pectoral exercises (OP). Methods: This study was conducted according to the PRISMA. Original research articles published by March 2023, were located using an electronic search of four databases and yielded 951 original publications. This review included studies that compared the EMG activity of pectoralis muscle between BP and OP. Data were extracted and independently coded by three researchers. Finally, 23 studies were included for systematic review and meta-analysis. Meta-analysis with fixed or random effect model was performed to infer the pooled estimated standardized mean difference, depending on the heterogeneity. The studies were grouped according to the type of the comparison: grip widths, type of grip, inclination of the bench, stability, or exercise type. Results: The original option of BP activates the sternal portion significantly more than the variant with the inclined bench (SMD = 1.80; 95%CI 0.40 to 3.19; p = 0.017). Performing the exercise in an unstable situation produced significantly more activation during the concentric phase than performing the exercise in a stable situation (SMD = −0.18; 95%CI −0.33 to 3.74; p = 0.029). When comparing by type of exercise, greater activations are also seen in the original bench press vs. the comparisons (p = 0.023 to 0.001). Conclusions: The results suggest that the traditional bench press performed with the bench in a horizontal position, with a bar and a grip width between 150% and 200% of the biacromial distance (BAD) results from a greater EMG involvement of the pectoralis major in most variations with the same relative load. However, the sternal portion of pectoralis major showed greater activation with the declined variant of bench press.

Comparison of Muscle Activity between the Horizontal Bench Press and the Seated Chest Press Exercises Using Several Grips.

This study aims to compare muscle activity in the pectoralis major, anterior deltoid, and triceps brachii in the horizontal bench press exercise with a prone grip at 150% and 50% of the biacromial width and the seated chest press exercise with two types of grips (a neutral grip at ~150% of the biacromial width and a prone grip at ~200% of the biacromial width). Twenty physically active adults performed a set of 8 repetitions at 60% of the one repetition maximum. The results showed that the clavicular portion of the pectoralis major had significantly greater muscle activity in the seated chest press exercise with a neutral grip (~30% of the maximal voluntary isometric contraction (MVIC)) than in the lying bench press exercise with a prone grip at 150% of the biacromial width (~25% MVIC). The muscle activity of the anterior deltoid was not significantly different across any exercise or grip evaluated (~24% MVIC). The muscle activity of the triceps brachii was significantly higher in the lying bench press exercise with a grip at 50% biacromial width (~16% MVIC) than at 150% of the biacromial width (~12% MVIC). In conclusion, all exercises and grips showed similar muscle activity, and the selection of these exercises should not be based exclusively on the grounds of muscle activation but rather on the load capacity lifted, the level of technique of the participant, and/or the transference to the specific sporting discipline or event.

Effect of instrument type and one-handed versus two-handed grips on force application during simulated instrument-assisted soft tissue mobilisation

ObjectiveThe purpose of this study was to examine whether the forces used by trained clinicians during a simulated instrument-assisted soft tissue mobilisation (IASTM) treatment varied across five different instruments during...

Soft-Sensor System for Grasp Type Recognition in Underactuated Hand Prostheses.

This paper presents the development of an intelligent soft-sensor system to add haptic perception to the underactuated hand prosthesis PrHand. Two sensors based on optical fiber were constructed, one for finger joint angles and the other for fingertips' contact force. Three sensor fabrications were tested for the angle sensor by axially rotating the sensors in four positions. The configuration with the most similar response in the four rotations was chosen. The chosen sensors presented a polynomial response with R2 higher than 92%. The tactile force sensors tracked the force made over the objects. Almost all sensors presented a polynomial response with R2 higher than 94%. The system monitored the prosthesis activity by recognizing grasp types. Six machine learning algorithms were tested: linear regression, k-nearest neighbor, support vector machine, decision tree, k-means clustering, and hierarchical clustering. To validate the algorithms, a k-fold test was used with a k = 10, and the accuracy result for k-nearest neighbor was 98.5%, while that for decision tree was 93.3%, enabling the classification of the eight grip types.