Repetition Count Research Articles

Using the Wrist-Worn Atlas Wristband2 Monitor to Objectively Measure Resistance Training Exercises

Background: Devices for monitoring physical activity have focused mainly on measuring aerobic activity; however, the 2018 Physical Activity Guidelines for Americans also recommend muscle-resistance training two or more days per week. Recently, a wrist-worn activity monitor, the Atlas Wristband2, was developed to recognize resistance training exercises. Purpose: To assess the ability of the Wristband2 to identify the type and number of repetitions of resistance training exercises, when worn on the left wrist as directed by the manufacturer, and when worn on the right wrist. Methods: While wearing monitors on both wrists, 159 participants completed a circuit-style workout consisting of two sets of 12 repetitions of 14 different resistance training exercises. Data from the monitors were used to determine classification accuracies for identifying exercise type verses direct observation. The average repetitions and mean absolute error (MAE) for repetitions were calculated for each exercise. Results: The Wristband2 classification accuracy for exercise type was 78.4 ± 2.5%, ranging from 54.7 ± 3.4% (dumbbell [DB] bench press) to 97.5 ± 1.0% (DB biceps curls), when worn on the left wrist. An average of 11.0 ± 0.2 repetitions, ranging from 9.0 ± 0.3 repetitions (DB lunges) to 11.9 ± 0.1 repetitions (push-ups), were identified. For all exercises, MAE ranged from 0.0–4.6 repetitions. When worn on the right wrist, exercise type classification accuracy dropped to 24.2 ± 5.1%, and repetitions decreased to 8.1 ± 0.8 out of 12. Conclusions: The Wristband2, worn on the left wrist, had acceptable exercise classification and repetition counting capabilities for many of the 14 exercises used in this study, and may be a useful tool to objectively track resistance training.

Rubber pole 충격 시 pole의 형상에 따른 조직의 수축과 pole의 온도특성에 관한 연구

In this study, the shrinkage at the artificial skin tissue and temperature characteristics of rubber pole were analyzed by the experimental and numerical method. A artificial skin tissue was produced by using the rigid sponge pad. The impact of tissue was applied by three types of rubber pole. The shrinkage results along the depth of tissue were measured according to the repetition count of impact. When the shape of rubber pole was sphere type, the shrinkage was greatest. The temperature around the pole was highest in the sphere type while that inside pole was greatest in the twine deep sphere type. This is because the pole temperature of twine deep sphere type was transmitted more inside. As a result, the sphere type rubber pole was the most effective because it showed the largest shrinkage and the lowest temperature gradient during impact.

Preliminary Examination of the Ability of a New Wearable Device to Capture Functional Hand Activity After Stroke.

Background and Purpose- A reliable measure of movement repetitions is required to assist in determining the optimal dose for maximizing upper limb recovery after stroke. This study investigated the ability of a new wearable device to capture reach-to-grasp repetitions in individuals with stroke. Methods- Eight individuals with stroke wore an instrumented wrist bracelet while completing 12 upper limb activities. Participants completed 5 and 10 repetitions of each activity on 2 separate sessions (time 1 and time 2) and completed clinical assessments (Fugl-Meyer Upper Extremity Assessment and Action Research Arm Test). Mean reach-to-grasp counts (ie, hand counts) were compared across activities. Scaling properties were assessed by the ratio of 10 repetitions to 5 repetitions for the activities (ie, expected value of 2). Bland-Altman diagrams were used to examine agreement between time 1 and time 2 counts. Results- The wrist bracelet averaged 0 to 0.6 hand counts per repetition for the arm-only and hand-only activities and averaged 1 to 2 counts per repetition of the reach-to-grasp activities. The mean ratio of 10 repetition to 5 repetition counts was ≈2 for all of the reach-to-grasp activities. Mean differences from time 1 to time 2 were <0.3 counts/repetition for all activities except one. Conclusions- These preliminary results provide evidence that the wrist bracelet is able to capture hand counts over a variety of tasks in a consistent manner. This wrist bracelet could be further developed as a tool to record dose of upper limb practice for research or clinical practice, as well as providing motivation and accountability to patients participating in treatments requiring upper limb movement repetitions. Currently, there are limitations in interpreting the impact of impairment and common compensatory movements on hand counts, and it would be valuable for future studies to explore these effects.

Repetition Estimation

Visual repetition is ubiquitous in our world. It appears in human activity (sports, cooking), animal behavior (a bee’s waggle dance), natural phenomena (leaves in the wind) and in urban environments (flashing lights). Estimating visual repetition from realistic video is challenging as periodic motion is rarely perfectly static and stationary. To better deal with realistic video, we elevate the static and stationary assumptions often made by existing work. Our spatiotemporal filtering approach, established on the theory of periodic motion, effectively handles a wide variety of appearances and requires no learning. Starting from motion in 3D we derive three periodic motion types by decomposition of the motion field into its fundamental components. In addition, three temporal motion continuities emerge from the field’s temporal dynamics. For the 2D perception of 3D motion we consider the viewpoint relative to the motion; what follows are 18 cases of recurrent motion perception. To estimate repetition under all circumstances, our theory implies constructing a mixture of differential motion maps: mathbf {F}, {varvec{nabla }}mathbf {F}, {varvec{nabla }}{varvec{cdot }} mathbf {F} and {varvec{nabla }}{varvec{times }} mathbf {F}. We temporally convolve the motion maps with wavelet filters to estimate repetitive dynamics. Our method is able to spatially segment repetitive motion directly from the temporal filter responses densely computed over the motion maps. For experimental verification of our claims, we use our novel dataset for repetition estimation, better-reflecting reality with non-static and non-stationary repetitive motion. On the task of repetition counting, we obtain favorable results compared to a deep learning alternative.

Correctable and uncorrectable errors using large scale DRAM DIMMs in replacement network servers

This paper investigated DRAM DIMM errors using field records in replacement network servers. Large DRAM samples of about 40 K were collected over a 2.5 years period from 23 different server types, included various DIMMs from three different DRAM manufacturers with densities between 4 and 128 GB, and speeds between 1066 and 2400 Mbps. Errors that occurred during system operation were classified as either correctable (CE) or uncorrectable (UE) errors based on error correction code (ECC) schemes built into the servers. Of the collected DIMMS, 24% had recorded errors, where CE-only, UE-only, and UE and CE together comprised 28%, 43%, and 29% of recorded errors, respectively. Since UEs can cause large-scale failures, systems are replaced upon any UE occurrence. Approximately half UE-only DIMMs had 1 UE error. In contrast, many DIMMs had billions of CE errors, where a faulty location may be repetitively accessed. Such drastic differences in UE and CE counts help explain the importance of ECC and error mitigation schemes. Comparative analyses of errors were made over the manufacturers and operating speeds. After reasonable adjustments for repetitive counts of errors, failure in time (FIT) differences were up to 38% over manufacturers. Higher speed DIMMs generally had higher FIT with 2400 Mbps DIMMs exhibiting 6.7 times FIT of 1066 Mbps DIMMs.

A Smart Glove to Track Fitness Exercises by Reading Hand Palm

Medical studies have intensively demonstrated that sports activity can enhance both the mental and the physical health of practitioners. In recent years, fitness activity became the most common way to motivate and engage people in sports activity. Recently, there have been multiple attempts to elaborate on the “ideal” IoT-based solution to track and assess these fitness activities. Most fitness activities (except aerobic activities like running) involve one or multiple interactions between the athlete’s hand palms and body or between the hand palms and the workout materials. In this work, we present our idea to exploit these biomechanical interactions of the hand palms to track fitness activities via a smart glove. Our smart glove-based system integrates force-sensitive resistor (FSR) sensors into wearable fitness gloves to identify and count fitness activity, by analyzing the time series of the pressure distribution in the hand palms observed during fitness sessions. To assess the performance of our proposed system, we conducted an experimental study with 10 participants over 10 common fitness activities. For the user-dependent activity recognition case, the experimental results showed 88.90% of the F score for overall activity recognition. The result of leave-one-participant-out cross-validation showed an F score ranging from 58.30% to 100%, with an average of 82.00%. For the exercise repetition count, the system achieved an average counting error of 9.85%, with a standard deviation of 1.38.

Programmed-Lattice Editor and accelerated processing of parametric program-representations of steady lattices

Our goal is to facilitate the design, analysis, optimization, and additive manufacturing of a specific class of 3D lattices that may comprise an extremely large number of elements. We target lattices that exhibit periodicity and uniform geometric gradations in three directions, along possibly curved axes. We propose a Parametric Program-Representation (PPR) of periodic lattices, wherein we represent a lattice by a program with a selected set of exposed control parameters that may be used to adjust the overall shape of the lattice, its repetition count in each direction, its microstructure, and its gradation. In our Programmed-Lattice Editor (PLE), a typical lattice is represented by a short program of 10 to 50 statements. We propose a simple API and a few rudimentary GUI tools that automate the creation of the corresponding expressions in the program. The overall shape and gradation of the lattice is controlled by three similarity transformations. This deliberate design choice ensures that the gradation in each direction is regular (i.e., mathematically steady), that each cell can be evaluated directly, without iterations, and that integral properties (such as surface area, volume, center of mass and spherical inertia of the whole lattice) can be obtained rapidly without having to calculate them for each individual element of the lattice.

Recognition and Repetition Counting for ComplexPhysical Exercises with Deep Learning.

Activity recognition using off-the-shelf smartwatches is an important problem in human activity recognition. In this paper, we present an end-to-end deep learning approach, able to provide probability distributions over activities from raw sensor data. We apply our methods to 10 complex full-body exercises typical in CrossFit, and achieve a classification accuracy of 99.96%. We additionally show that the same neural network used for exercise recognition can also be used in repetition counting. To the best of our knowledge, our approach to repetition counting is novel and performs well, counting correctly within an error of ±1 repetitions in 91% of the performed sets.

Effect of Knee Compression on Kinetic Variables During Vertical Jumps

Abstract The purpose of this study was to determine how knee compression affected kinetic variables during vertical jumps. Ten healthy males, age 20s, performed a single maximum vertical jump and a ten-consecutive vertical jump trial without knee compression (control condition) and with knee compression. The collected data of ground reaction force were used to analyse the vertical jump height (VJH), peak active force (PAF), decay rate (DR), peak passive force (PPF), loading rate (LR), and the coefficient of variation (CV). During a maximum vertical jump, knee compression increased the magnitudes of DR, PAF, and VJH by 19.8%, 3.41%, and 4.87%, respectively, compared to those under a control condition. During ten consecutive vertical jumps, PAF and VJH showed statistically significant difference according to the repetition count. Also, the mean and CV of PAF, DR, LR, and VJH over consecutive jumps were higher in magnitude under knee compression condition than under the control condition.

Resistance Training Volume Load with and without Exercise Displacement.

Monitoring the resistance training volume load (VL) (sets × reps × load) is essential to managing resistance training and the recovery–adaptation process. Subjects: Eight trained weightlifters, seven of which were at national level, participated in the study. Methods: VL was measured both with (VLwD) and without (VL) the inclusion of barbell displacement, across twenty weeks of training, in order to allow for comparisons to be made of these VL calculating methods. This consisted of recording the load, repetition count, and barbell displacement for every set executed. Comparisons were made between VL and VLwD for individual blocks of training, select training weeks, and select training days. Results: Strong, statistically significant correlations (r ≥ 0.78, p < 0.001) were observed between VL and VLwD between all training periods analyzed. t-tests revealed statistically significant (p ≤ 0.018) differences between VL and VLwD in four of the seven training periods analyzed. Conclusion: The very strong relationship between VL and VLwD suggest that a coach with time constraints and a large number of athletes can potentially spare the addition of displacement. However, differences in percent change indicate that coaches with ample time should include displacement in VL calculations, in an effort to acquire more precise workload totals.

When Virtual Reality Meets Internet of Things in the Gym

With the advent of immersive virtual reality (VR) head-mounted displays (HMD), we envision that immersive VR will revolutionize the personal fitness experience in our daily lives. Toward this vision, we present JARVIS, a virtual exercise assistant that is able to provide an immersive and interactive gym exercise experience to a user. JARVIS is enabled by the synergy between Internet of Things (IoT) and immersive VR. JARVIS employs miniature IoT sensing devices removably attachable to exercise machines to track a multitude of exercise information including exercise types, repetition counts, and progress within each repetition in real time. Based on the tracked exercise information, JARVIS shows the user the proper way of doing the exercise in the virtual exercise environment, thereby helping the user to better focus on the target muscle group. We have conducted both in-lab experiments and a pilot user study to evaluate the performance and effectiveness of JARVIS, respectively. Our in-lab experiments with fifteen participants show that JARVIS is able to segment exercise repetitions with an average accuracy of 97.96% and recognize exercise types with an average accuracy of 99.08%. Our pilot user study with ten participants shows statistically significant improvements in perceived enjoyment, competence, and usefulness with JARVIS compared to a traditional machine exercise setting (p &lt; 0.05). Finally, our surface electromyography (sEMG) signal analysis conducted during the pilot user study shows statistically significant improvement in terms of muscle activation (p &lt; 0.01), indicating the potential of JARVIS in providing an engaging and effective guidance for machine exercises.

Automatic matching of construction onsite resources under camera views

When a video camera network is placed on a construction site to monitor onsite activities, construction resources, such as equipment and worker, might be captured by two or more cameras at the same time. Therefore, it is important to conduct the matching to identify whether the resources captured into separate camera views refer to the same one on the site. Otherwise, it leads to the repetitive counting, when analyzing the onsite resources utilization automatically. This paper proposes a novel matching method that relies on the construction site visual features and the spatial relationships of onsite construction resources as the matching cues. Specifically, the method first searches the potential matching candidates between two camera views following their epipolar constraints. Then, the triangular coordinates of these candidates are calculated based on their locations in the triangular mesh of each camera view. This way, the matching of multiple construction resources between two camera views could be converted to a combinatorial optimization problem and solved with the Hungarian algorithm. The proposed method has been tested with the images and videos captured from real construction sites. The test results showed that the average matching accuracy could reach 93%.

A Wearable Sensor-Based Exercise Biofeedback System: Mixed Methods Evaluation of Formulift.

BackgroundFormulift is a newly developed mobile health (mHealth) app that connects to a single inertial measurement unit (IMU) worn on the left thigh. The IMU captures users’ movements as they exercise, and the app analyzes the data to count repetitions in real time and classify users’ exercise technique. The app also offers feedback and guidance to users on exercising safely and effectively.ObjectiveThe aim of this study was to assess the Formulift system with three different and realistic types of potential users (beginner gym-goers, experienced gym-goers, and qualified strength and conditioning [S&C] coaches) under a number of categories: (1) usability, (2) functionality, (3) the perceived impact of the system, and (4) the subjective quality of the system. It was also desired to discover suggestions for future improvements to the system.MethodsA total of 15 healthy volunteers participated (12 males; 3 females; age: 23.8 years [SD 1.80]; height: 1.79 m [SD 0.07], body mass: 78.4 kg [SD 9.6]). Five participants were beginner gym-goers, 5 were experienced gym-goers, and 5 were qualified and practicing S&C coaches. IMU data were first collected from each participant to create individualized exercise classifiers for them. They then completed a number of nonexercise-related tasks with the app. Following this, a workout was completed using the system, involving squats, deadlifts, lunges, and single-leg squats. Participants were then interviewed about their user experience and completed the System Usability Scale (SUS) and the user version of the Mobile Application Rating Scale (uMARS). Thematic analysis was completed on all interview transcripts, and survey results were analyzed.ResultsQualitative and quantitative analysis found the system has “good” to “excellent” usability. The system achieved a mean (SD) SUS usability score of 79.2 (8.8). Functionality was also deemed to be good, with many users reporting positively on the systems repetition counting, technique classification, and feedback. A number of bugs were found, and other suggested changes to the system were also made. The overall subjective quality of the app was good, with a median star rating of 4 out of 5 (interquartile range, IQR: 3-5). Participants also reported that the system would aid their technique, provide motivation, reassure them, and help them avoid injury.ConclusionsThis study demonstrated an overall positive evaluation of Formulift in the categories of usability, functionality, perceived impact, and subjective quality. Users also suggested a number of changes for future iterations of the system. These findings are the first of their kind and show great promise for wearable sensor-based exercise biofeedback systems.

Examination of the Relationship between Straight Leg Raising Repetition Count and both Knee Extension Strength and Walking Independence in Patients with Collagen Disease.

The aim of the current study was to examine the relationship between the straight leg raising (SLR) repetition count and both the knee extension strength (KES) and walking independence. We enrolled 106 inpatients aged ≥20 years with collagen disease in a cross-sectional study. We measured the SLR repetition count, KES, and walking independence of each participant. The correlations between the SLR repetition count and KES/walking independence were then examined. Furthermore, patients were divided into three groups depending on their SLR repetition count (low, medium, or high), and the differences among the groups were analyzed. A moderately significant correlation was found between the SLR repetition count and KES (right: r=0.46, P<0.01; left: r=0.55, P<0.01). Moreover, there was a strong correlation between the maximum SLR repetition count and walking independence (r=0.74, P<0.01). Differences in KES and walking independence were observed among the SLR repetition groups (P<0.01). KES and walking independence in the group with a low repetition count were 0.08±0.04 kgf/kg and 1 (1-4) point, whereas the values in the group with a medium repetition count were 0.25±0.08 kgf/kg and 5 (1-7) points and those in the group with a high repetition count were 0.40±0.13 kgf/kg and 7 (4-7) points. The SLR repetition count is related to KES and walking independence. SLR repetition counts can be used in the clinical setting for the assessment of lower limb strength and walking independence.

The role of short-term memory impairment in nonword repetition, real word repetition, and nonword decoding: A case study

ABSTRACTIn a companion study, adults with dyslexia and adults with a probable history of childhood apraxia of speech showed evidence of difficulty with processing sequential information during nonword repetition, multisyllabic real word repetition and nonword decoding. Results suggested that some errors arose in visual encoding during nonword reading, all levels of processing but especially short-term memory storage/retrieval during nonword repetition, and motor planning and programming during complex real word repetition. To further investigate the role of short-term memory, a participant with short-term memory impairment (MI) was recruited. MI was confirmed with poor performance during a sentence repetition and three nonword repetition tasks, all of which have a high short-term memory load, whereas typical performance was observed during tests of reading, spelling, and static verbal knowledge, all with low short-term memory loads. Experimental results show error-free performance during multisyllabic real word repetition but high counts of sequence errors, especially migrations and assimilations, during nonword repetition, supporting short-term memory as a locus of sequential processing deficit during nonword repetition. Results are also consistent with the hypothesis that during complex real word repetition, short-term memory is bypassed as the word is recognized and retrieved from long-term memory prior to producing the word.

Numerical Analysis of Welding Residual Stress Relaxation in High-Strength Multilayer Weldment Under Fatigue Loads

The primary purpose of this investigation was to study welding residual stress relaxation by repeated loading. A coupling finite element analysis model for prediction of the welding residual stress and the mechanical stress relaxation after external repeated loads was presented. The accuracy of this model was verified through experiments. Also, it is found that the residual stress of weldment is relaxed by external loads, and the greatest amount of relaxation was obtained by early repeated loads. As the repetition count increased, the amount of relaxation became smaller than the amount of relaxation in the early stage.

The short-term effect of high versus moderate protein intake on recovery after strength training in resistance-trained individuals

BackgroundDietary protein intakes up to 2.9 g.kg−1.d−1 and protein consumption before and after resistance training may enhance recovery, resulting in hypertrophy and strength gains. However, it remains unclear whether protein quantity or nutrient timing is central to positive adaptations. This study investigated the effect of total dietary protein content, whilst controlling for protein timing, on recovery in resistance trainees.MethodsFourteen resistance-trained individuals underwent two 10-day isocaloric dietary regimes with a protein content of 1.8 g.kg−1.d−1 (PROMOD) or 2.9 g.kg−1.d−1 (PROHIGH) in a randomised, counterbalanced, crossover design. On days 8–10 (T1-T3), participants undertook resistance exercise under controlled conditions, performing 3 sets of squat, bench press and bent-over rows at 80% 1 repetition maximum until volitional exhaustion. Additionally, participants consumed a 0.4 g.kg−1 whey protein concentrate/isolate mix 30 min before and after exercise sessions to standardise protein timing specific to training. Recovery was assessed via daily repetition performance, muscle soreness, bioelectrical impedance phase angle, plasma creatine kinase (CK) and tumor necrosis factor-α (TNF-α).ResultsNo significant differences were reported between conditions for any of the performance repetition count variables (p > 0.05). However, within PROMOD only, squat performance total repetition count was significantly lower at T3 (19.7 ± 6.8) compared to T1 (23.0 ± 7.5; p = 0.006). Pre and post-exercise CK concentrations significantly increased across test days (p ≤ 0.003), although no differences were reported between conditions. No differences for TNF-α or muscle soreness were reported between dietary conditions. Phase angle was significantly greater at T3 for PROHIGH (8.26 ± 0.82°) compared with PROMOD (8.08 ± 0.80°; p = 0.012).ConclusionsWhen energy intake and peri-exercise protein intake was controlled for, a short term PROHIGH diet did not improve markers of muscle damage or soreness in comparison to a PROMOD approach following repeated days of intensive training. Whilst it is therefore likely that moderate protein intakes (1.8 g.kg−1.d−1) may be sufficient for resistance-trained individuals, it is noteworthy that both lower body exercise performance and bioelectrical phase angle were maintained with PROHIGH. Longer term interventions are warranted to determine whether PROMOD intakes are sufficient during prolonged training periods or when extensive exercise (e.g. training twice daily) is undertaken.

Examination of Simple Outcome Measures and Cut-off Values Related to Walking Independence of Inpatients with Medical Diseases in Acute Care Hospitals.

The objective of the current study was to identify simple outcome measures to predict walking independence in inpatients with medical diseases in acute care hospitals and to identify the cut-off values of the relevant measures. Two hundred inpatients aged 20 years or above who had a medical disease were enrolled in this cross-sectional study. The subjects' walking independence, physical characteristics, cognitive status, and blood test data were examined. Logistic regression analysis was performed, and cut-off values were calculated. The identified outcome measures and their respective cut-off values were as follows: the straight leg raising (SLR) repetition count, 27; the one-leg standing time (OLST), 3.6 s; and the orientation score of the mini-mental state examination (MMSE), 9/10. Our study findings suggest that the SLR repetition count, OLST, and the MMSE orientation score are simple outcome measures related to walking independence in inpatients with medical diseases in acute care hospitals.

Qualitative Importance Measures of Systems Components – A New Approach and Its Applications

Abstract The paper presents an improved methodology of analysing the qualitative importance of components in the functional and reliability structures of the system. We present basic importance measures, i.e. the Birnbaum’s structural measure, the order of the smallest minimal cut-set, the repetition count of an i-th event in the Fault Tree and the streams measure. A subsystem of circulation pumps and fuel heaters in the main engine fuel supply system of a container vessel illustrates the qualitative importance analysis. We constructed a functional model and a Fault Tree which we analysed using qualitative measures. Additionally, we compared the calculated measures and introduced corrected measures as a tool for improving the analysis. We proposed scaled measures and a common measure taking into account the location of the component in the reliability and functional structures. Finally, we proposed an area where the measures could be applied.

Picosecond Laser Surface Cleaning of AM1 Superalloy

Laser scanning processing of nickel-based superalloy AM1 surfaces by ultra-short pulses (10 ps) is introduced as a cleaning and deoxidation postprocess. The laser cleaning is investigated with two-directional surface scanning by a laser beam with several frequencies of pulse generation. The EDX elemental analyses of the laser cleaned AM1 surfaces were compared with the non-laser treated surface. The optimal speed, laser pulse repetition frequency, overlapping and layer repetition count are determined for minimal structural changes on the mechanically polished AM1 surfaces. The laser cleaning after shifted laser surface texturing (sLST) is presented as a two-step preparation of a superalloy surface for thermal spraying. The heat accumulation effect and temperature fields are calculated from a semi-planar model of a laser beam scanning heat source. The theoretical results are discussed in comparison with experimental studies. The upper and bottom bounds are defined for an optimal high speed laser cleaning process.