Research

17 pages, 3827 KiB

Open AccessArticle

The Comfort and Measurement Precision-Based Multi-Objective Optimization Method for Gesture Interaction

by Wenjie Wang, Yongai Hou, Shuangwen Tian, Xiansheng Qin, Chen Zheng, Liting Wang, Hepeng Shang and Yuangeng Wang

Bioengineering 2023, 10(10), 1191; https://doi.org/10.3390/bioengineering10101191 - 13 Oct 2023

Viewed by 1042

Abstract

As an advanced interaction mode, gestures have been widely used for human–computer interaction (HCI). This paper proposes a multi-objective optimization method based on the objective function

J_{C P}

to solve the inconsistency between the gesture comfort

J_{C S}

and measurement precision [...] Read more.

As an advanced interaction mode, gestures have been widely used for human–computer interaction (HCI). This paper proposes a multi-objective optimization method based on the objective function

J_{C P}

to solve the inconsistency between the gesture comfort

J_{C S}

and measurement precision

J_{P_{H}}

in the gesture interaction. The proposed comfort model

C S

takes seventeen muscles and six degrees of freedom into consideration based on the data from muscles and joints, and is capable of simulating the energy expenditure of the gesture motion. The

C S

can provide an intuitive indicator to predict which act has the higher risk of fatigue or injury for joints and muscles. The measurement precision model

{∆ P}_{H}

is calculated from the measurement error

({∆ X}_{H}, {∆ Y}_{H}, {∆ Z}_{H})

caused by calibration, that provides a means to evaluate the efficiency of the gesture interaction. The modeling and simulation are implemented to analyze the effectiveness of the multi-objective optimization method proposed in this paper. According to the result of the comparison between the objective function

J_{C S}

, based on the comfort model

C S

, and the objective function

J_{P_{H}}

, based on the measurement precision models

{∆ P}_{H}

, the consistency and the difference can be found due to the variation of the radius

r_{B_R H O}

and the center coordinates

P_{B_R H O} (x_{B_R H O}, y_{B_R H O}, z_{B_R H O})

. The proposed objective function

J_{C P}

compromises the inconsistency between the objective function

J_{C S}

and

J_{P_{H}}

. Therefore, the multi-objective optimization method proposed in this paper is applied to the gesture design to improve the ergonomics and operation efficiency of the gesture, and the effectiveness is verified through usability testing. Full article

(This article belongs to the Special Issue Human Movement and Ergonomics)

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16 pages, 1621 KiB

Open AccessEditor’s ChoiceArticle

Correlations between Ratings and Technical Measurements in Hand-Intensive Work

by Gunilla Dahlgren, Per Liv, Fredrik Öhberg, Lisbeth Slunga Järvholm, Mikael Forsman and Börje Rehn

Bioengineering 2023, 10(7), 867; https://doi.org/10.3390/bioengineering10070867 - 21 Jul 2023

Viewed by 1403

Abstract

An accurate rating of hand activity and force is essential in risk assessment and for the effective prevention of work-related musculoskeletal disorders. However, it is unclear whether the subjective ratings of workers and observers correlate to corresponding objective technical measures of exposure. Fifty-nine [...] Read more.

An accurate rating of hand activity and force is essential in risk assessment and for the effective prevention of work-related musculoskeletal disorders. However, it is unclear whether the subjective ratings of workers and observers correlate to corresponding objective technical measures of exposure. Fifty-nine workers were video recorded while performing a hand-intensive work task at their workplace. Self-ratings of hand activity level (HAL) and force (Borg CR10) using the Hand Activity Threshold Limit Value^® were assessed. Four ergonomist observers, in two pairs, also rated the hand activity and force level for each worker from video recordings. Wrist angular velocity was measured using inertial movement units. Muscle activity in the forearm muscles flexor carpi radialis (FCR) and extensor carpi radialis (ECR) was measured with electromyography root mean square values (RMS) and normalized to maximal voluntary electrical activation (MVE). Kendall’s tau-b correlations were statistically significant between self-rated hand activity and wrist angular velocity at the 10th, 50th, and 90th percentiles (0.26, 0.31, and 0.23) and for the ratings of observers (0.32, 0.41, and 0.34). Significant correlations for force measures were found only for observer-ratings in five of eight measures (FCR 50th percentile 0.29, time > 10%MVE 0.43, time > 30%MVE 0.44, time < 5% −0.47) and ECR (time > 30%MVE 0.26). The higher magnitude of correlation for observer-ratings suggests that they may be preferred to the self-ratings of workers. When possible, objective technical measures of wrist angular velocity and muscle activity should be preferred to subjective ratings when assessing risks of work-related musculoskeletal disorders. Full article

(This article belongs to the Special Issue Human Movement and Ergonomics)

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15 pages, 673 KiB

Open AccessArticle

The Impact of Peripheral Vision on Manual Reaction Time Using Fitlight Technology for Handball, Basketball and Volleyball Players

by Dana Badau, Alina Mihaela Stoica, Marin Florin Litoi, Adela Badau, Daniel Duta, Cezar Gheorghe Hantau, Anca Maria Sabau, Bogdan Marian Oancea, Catalin Vasile Ciocan, Julien Leonard Fleancu and Bogdan Gozu

Bioengineering 2023, 10(6), 697; https://doi.org/10.3390/bioengineering10060697 - 07 Jun 2023

Cited by 2 | Viewed by 2611

Abstract

The purpose of the research was to identify the impact of peripheral (unilateral and bilateral) vision on manual reaction time to visual stimuli in handball, basketball and volleyball players by implementing a 6-week experimental program of specific exercises and some adapted tests using [...] Read more.

The purpose of the research was to identify the impact of peripheral (unilateral and bilateral) vision on manual reaction time to visual stimuli in handball, basketball and volleyball players by implementing a 6-week experimental program of specific exercises and some adapted tests using Fitlight technology. The research included 412 players (212 male—51.5%; 200 female—48.5%) from three team sports: basketball—146 (35.4%), handball—140 (40%) and volleyball—126 (30.6%). The experimental program carried out over 6 weeks was identical for all handball, basketball and volleyball players participating in the study; two training sessions per week were performed, with each session lasting 30 min; 15 exercises were used for the improvement of manual reaction time to visual stimuli involving peripheral vision. Through the Analysis of Variance (ANOVA), we identified statistically significant differences between the arithmetic means of the samples of handball, basketball and volleyball players, as well as according to general samples also of gender (male and female), p = 0.000. Male and female handball samples achieved the greatest progress in manual reaction time to visual stimuli involving peripheral vision for the Reaction time test with a unilateral right visual stimulus (30 s) and the Reaction time test with a unilateral left visual stimulus (30 s), while general sample also of male and female basketball samples, for the Reaction time test with bilateral visual stimuli (30 s) and the Reaction time test with six Fitlights (1 min); male and female volleyball samples recorded the lowest progress in all tests compared to handball and basketball groups. According to our results, female samples made greater progress in reaction time than male groups for all four tests of the present study. The implemented experimental program led to an improvement in manual reaction time to visual stimuli due to the use of Fitlight technology and the involvement of peripheral vision for all research samples. Full article

(This article belongs to the Special Issue Human Movement and Ergonomics)

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13 pages, 603 KiB

Open AccessArticle

A Twenty-Year Retrospective Analysis of Risk Assessment of Biomechanical Overload of the Upper Limbs in Multiple Occupational Settings: Comparison of Different Ergonomic Methods

by Emma Sala, Lorenzo Cipriani, Andrea Bisioli, Emilio Paraggio, Cesare Tomasi, Pietro Apostoli and Giuseppe De Palma

Bioengineering 2023, 10(5), 580; https://doi.org/10.3390/bioengineering10050580 - 11 May 2023

Cited by 1 | Viewed by 1361

Abstract

Background: Several methods with which to assess the risk of biomechanical overload of the upper limb are described in the literature. Methods: We retrospectively analysed the results of the risk assessment of the biomechanical overload of the upper limb in multiple settings by [...] Read more.

Background: Several methods with which to assess the risk of biomechanical overload of the upper limb are described in the literature. Methods: We retrospectively analysed the results of the risk assessment of the biomechanical overload of the upper limb in multiple settings by comparing the application of the Washington State Standard, the threshold limit values (TLV) proposed by the American Conference of Governmental Industrial Hygienists (ACGIH), based on hand-activity levels (HAL) and normalised peak force (PF), the Occupational Repetitive Actions (OCRA) checklist, the Rapid Upper-Limb Assessment (RULA), and the Strain Index and Outil de Repérage et d’Evaluation des Gestes of INRS (Institut National de Recherche et de Sécurité). Results: Overall, 771 workstations were analysed for a total of 2509 risk assessments. The absence of risk demonstrated for the Washington CZCL, used as the screening method, was in good agreement with the other methods, with the sole exception of the OCRA CL, which showed at-risk conditions in a higher percentage of workstations. Differences in the assessment of the frequency of actions were observed among the methods, while their assessments of strength appeared to be more uniform. However, the greatest discrepancies were observed in the assessment of posture. Conclusions: The use of multiple assessment methods ensures a more adequate analysis of biomechanical risk, allowing researchers to investigate the factors and segments in which different methods show different specificities. Full article

(This article belongs to the Special Issue Human Movement and Ergonomics)

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14 pages, 1689 KiB

Open AccessArticle

Testing the Level of Agreement between Two Methodological Approaches of the Rapid Upper Limb Assessment (RULA) for Occupational Health Practice—An Exemplary Application in the Field of Dentistry

by Ramona Nowara, Fabian Holzgreve, Rejane Golbach, Eileen M. Wanke, Christian Maurer-Grubinger, Christina Erbe, Doerthe Brueggmann, Albert Nienhaus, David A. Groneberg and Daniela Ohlendorf

Bioengineering 2023, 10(4), 477; https://doi.org/10.3390/bioengineering10040477 - 15 Apr 2023

Cited by 1 | Viewed by 1616

Abstract

Background: The Rapid Upper Limb Assessment (RULA) is used for the risk assessment of workplace-related activities. Thus far, the paper and pen method (RULA-PP) has been predominantly used for this purpose. In the present study, this method was compared with an RULA evaluation [...] Read more.

Background: The Rapid Upper Limb Assessment (RULA) is used for the risk assessment of workplace-related activities. Thus far, the paper and pen method (RULA-PP) has been predominantly used for this purpose. In the present study, this method was compared with an RULA evaluation based on kinematic data using inertial measurement units (RULA-IMU). The aim of this study was, on the one hand, to work out the differences between these two measurement methods and, on the other, to make recommendations for the future use of the respective method on the basis of the available findings. Methods: For this purpose, 130 (dentists + dental assistants, paired as teams) subjects from the dental profession were photographed in an initial situation of dental treatment and simultaneously recorded with the IMU system (Xsens). In order to compare both methods statistically, the median value of the difference of both methods, the weighted Cohen’s Kappa, and the agreement chart (mosaic plot) were applied. Results: In Arm and Wrist Analysis—area A—here were differences in risk scores; here, the median difference was 1, and the agreement in the weighted Cohen’s kappa test also remained between 0.07 and 0.16 (no agreement to poor agreement). In area B—Neck, Trunk, and Leg Analysis—the median difference was 0, with at least one poor agreement in the Cohen’s Kappa test of 0.23–0.39. The final score has a median of 0 and a Cohen’s Kappa value of 0.21–0.28. In the mosaic plot, it can be seen that RULA-IMU had a higher discriminatory power overall and more often reached a value of 7 than RULA-PP. Conclusion: The results indicate a systematic difference between the methods. Thus, in the RULA risk assessment, RULA-IMU is mostly one assessment point above RULA-PP. Therefore, future study results of RULA by RULA-IMU can be compared with literature results obtained by RULA-PP to further improve the risk assessment of musculoskeletal diseases. Full article

(This article belongs to the Special Issue Human Movement and Ergonomics)

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11 pages, 788 KiB

Open AccessArticle

Characterization of Postural Sway in Women with Osteoporosis and a Control Group by Means of Linear and Nonlinear Methods

by Felix Stief, Anna Sohn, Lutz Vogt, Andrea Meurer and Marietta Kirchner

Bioengineering 2023, 10(4), 403; https://doi.org/10.3390/bioengineering10040403 - 24 Mar 2023

Cited by 1 | Viewed by 1070

Abstract

The mechanisms underlying the altered postural control and risk of falling in patients with osteoporosis are not yet fully understood. The aim of the present study was to investigate postural sway in women with osteoporosis and a control group. The postural sway of [...] Read more.

The mechanisms underlying the altered postural control and risk of falling in patients with osteoporosis are not yet fully understood. The aim of the present study was to investigate postural sway in women with osteoporosis and a control group. The postural sway of 41 women with osteoporosis (17 fallers and 24 non-fallers) and 19 healthy controls was measured in a static standing task with a force plate. The amount of sway was characterized by traditional (linear) center-of-pressure (COP) parameters. Structural (nonlinear) COP methods include spectral analysis by means of a 12-level wavelet transform and a regularity analysis via multiscale entropy (MSE) with determination of the complexity index. Patients showed increased body sway in the medial–lateral (ML) direction (standard deviation in mm: 2.63 ± 1.00 vs. 2.00 ± 0.58, p = 0.021; range of motion in mm: 15.33 ± 5.58 vs. 10.86 ± 3.14, p = 0.002) and more irregular sway in the anterior–posterior (AP) direction (complexity index: 13.75 ± 2.19 vs. 11.18 ± 4.44, p = 0.027) relative to controls. Fallers showed higher-frequency responses than non-fallers in the AP direction. Thus, postural sway is differently affected by osteoporosis in the ML and AP directions. Clinically, effective assessment and rehabilitation of balance disorders can benefit from an extended analysis of postural control with nonlinear methods, which may also contribute to the improvement of risk profiles or a screening tool for the identification of high-risk fallers, thereby prevent fractures in women with osteoporosis. Full article

(This article belongs to the Special Issue Human Movement and Ergonomics)

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Review

Jump to: Research, Other

38 pages, 1633 KiB

Open AccessReview

A Review on the Usability, Flexibility, Affinity, and Affordability of Virtual Technology for Rehabilitation Training of Upper Limb Amputees

by Xiangyu Liu, Di Zhang, Ke Miao, Yao Guo, Xinyu Jiang, Xi Zhang, Fumin Jia, Hao Tang and Chenyun Dai

Bioengineering 2023, 10(11), 1301; https://doi.org/10.3390/bioengineering10111301 - 09 Nov 2023

Viewed by 1322

Abstract

(1) Background: Prosthetic rehabilitation is essential for upper limb amputees to regain their ability to work. However, the abandonment rate of prosthetics is higher than 50% due to the high cost of rehabilitation. Virtual technology shows potential for improving the availability and cost-effectiveness [...] Read more.

(1) Background: Prosthetic rehabilitation is essential for upper limb amputees to regain their ability to work. However, the abandonment rate of prosthetics is higher than 50% due to the high cost of rehabilitation. Virtual technology shows potential for improving the availability and cost-effectiveness of prosthetic rehabilitation. This article systematically reviews the application of virtual technology for the prosthetic rehabilitation of upper limb amputees. (2) Methods: We followed PRISMA review guidance, STROBE, and CASP to evaluate the included articles. Finally, 17 articles were screened from 22,609 articles. (3) Results: This study reviews the possible benefits of using virtual technology from four aspects: usability, flexibility, psychological affinity, and long-term affordability. Three significant challenges are also discussed: realism, closed-loop control, and multi-modality integration. (4) Conclusions: Virtual technology allows for flexible and configurable control rehabilitation, both during hospital admissions and after discharge, at a relatively low cost. The technology shows promise in addressing the critical barrier of current prosthetic training issues, potentially improving the practical availability of prosthesis techniques for upper limb amputees. Full article

(This article belongs to the Special Issue Human Movement and Ergonomics)

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Other

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11 pages, 1391 KiB

Open AccessBrief Report

The Three-Dimensional Body Center of Mass at the Workplace under Hypogravity

by Tatiana Maillard

Bioengineering 2023, 10(10), 1221; https://doi.org/10.3390/bioengineering10101221 - 19 Oct 2023

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Abstract

The center of mass dynamics of the seated posture of humans in a work environment under hypogravity (0 < g < 1) have rarely been investigated, and such research is yet to be carried out. The present study determined the difference in the [...] Read more.

The center of mass dynamics of the seated posture of humans in a work environment under hypogravity (0 < g < 1) have rarely been investigated, and such research is yet to be carried out. The present study determined the difference in the body system of 32 participants working under simulated 1/6 g (Moon) and 1 g (Earth) for comparison using static and dynamic task measurements. This was based on a markerless motion capture method that analyzed participants’ center of mass at the start, middle and end of the task when they began to get fatigued. According to this analysis, there is a positive relationship (p < 0.01) with a positive coefficient of correlation between the downward center of mass body shift along the proximodistal axis and gravity level for males and females. At the same time, the same positive relationship (p < 0.01) between the tilt of the body backward along the anterior–posterior axis and the level of gravity was found only in females. This offers fresh perspectives for comprehending hypogravity in a broader framework regarding its impact on musculoskeletal disorders. It can also improve workplace ergonomics, body stability, equipment design, and biomechanics. Full article

(This article belongs to the Special Issue Human Movement and Ergonomics)

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