We propose a linear regression model for the estimation of human body measurements. The input to the model only consists of the information that a person can self-estimate, such as height and weight. ...We evaluate our model against the state-of-the-art approaches for body measurement from point clouds and images, demonstrate the comparable performance with the best methods, and even outperform several deep learning models on public datasets. The simplicity of the proposed regression model makes it perfectly suitable as a baseline in addition to the convenience for applications such as the virtual try-on. To improve the repeatability of the results of our baseline and the competing methods, we provide guidelines toward standardized body measurement estimation.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Low back pain (LBP) is a global health-problem phenomenon. Most patients are categorized as non-specific, thus requiring an individualized approach which still poses a major challenge. In this paper, ...sEMG recordings from two pairs of lumbar muscle sites were collected during an isometric trunk extension exercise. Ninety-one subjects were included in the study; 29 patients with non-specific chronic LBP (CLBP), 25 patients with radiculopathy (RLBP), and 37 control healthy subjects (HS). Six best-performing time-domain raw features were employed to model contextual secondary feature groups. Neuromuscular LBP characteristics were described with coordination, co-activation, trends, and fatigue measures. Altogether, a set of 327 secondary features was created where inputs into the classification models were further refined by employing neighborhood component analysis (NCA). NCA effectively reduced the number of features (<20 components), alongside preserving them in the original interpretable domain. A set of 23 different classifiers was employed and explored, resulting in classification accuracy of 0.94 for HS vs. LBP, 0.89 for HS vs. CLBP, 0.98 for HS vs. RLBP, and 0.89 for CLBP vs. RLBP differentiation. High median precision (0.97) and sensitivity (0.99) across all classifiers for HS vs. RLBP differentiation was obtained, with only three feature components utilized (out of 327). Support vector machines (SVM) and <inline-formula> <tex-math notation="LaTeX">{k} </tex-math></inline-formula>-nearest neighbor (<inline-formula> <tex-math notation="LaTeX">{k} </tex-math></inline-formula>NN) based classifiers consistently demonstrated best classification results. Different profiles of CLBP patients were presented and discussed. The suggested method demonstrated the potential for patients' subgrouping and subsequent more individualized rehabilitation treatments, backed by medical interpretations through feature modeling.
The large body of published literature has shown that the effects of strength training can transfer from trained to untrained homologous limb muscles after unilateral training. These effects on ...strength have been shown to be very specific to the type and speed of training contraction. The aim of this study was to investigate the effects of a 4-week unilateral slow and fast velocity isokinetic concentric training, to compare the effects, and thus investigate whether these effects are speed-specific. Forty-four healthy female students allocated to slow training, fast training, or control performed 12 isokinetic concentric-concentric plantar/dorsal flexors training sessions (3 × 4 weeks) using their nondominant leg. Participants in the two experimental groups showed statistically significant gains in strength in both the trained (ranging from 8 to 41%) and untrained leg (5-26%), thus showing cross-education on strength effects. The present study demonstrated that 4 weeks (12 training sessions) of unilateral isokinetic resistance training in the concentric mode improved the strength of contralateral, untrained homologous muscles to the same extent, regardless of the contraction velocity used in females. Furthermore, the amount of concentric overload (50% more than during 60°/s) did not appear to affect the increase in strength gains. Therefore, practitioners are encouraged to use both training speeds when strength gains in the contralateral leg are the primary goal. If the training time is limited, however, training with a higher contraction speed is recommended.
Although the measurements of the lumbar spine and pelvic flexion have shown that subjects with radiculopathy exhibited greater decreases of motion when compared with subjects with low back pain, ...there is still a lack of evidence regarding the changes in flexion relaxation ratio in patients with radiculopathy. The aims of this study were to investigate the flexion relaxation ratio and flexion of the lumbar spine and pelvis in subjects with low back pain (LBP) and LBP with radiculopathy (LBPR) in comparison with healthy subjects (CG-control group). A total of 146 participants were divided in three groups: LBP patients (54 males; 21 females); LBPR patients (26 males; 11 females); and CG subjects (16 males; 18 females). The lumbar spine and pelvis flexion was recorded using optoelectronic motion capture system. The electrical activity of the erector spinae muscles was assessed by surface electromyography during flexion-extension movements. Comparisons between groups were made using one-way ANOVA tests and Mann-Whithney U test with the level of statistical significance at 0.05. The lumbar and pelvic flexion and electromyography of the erector spinae muscle showed significant differences between LBP and LBPR patients compared to CG. Patients LBPR showed significantly smaller angles of lumbar and pelvic flexion compared to LBP patients and CG. An increase in the erector spinae muscle activity during flexion was also observed in patients with radiculopathy. The increased muscular activity of the erector spinae is related to the reduced flexion of the lumbar spine in order to protect the lumbar spine structure. Measurements of trunk, lumbar spine and pelvic flexion, and the flexion relaxation ratio may allow us to predict better outcomes or responsiveness to treatment of LBPR patients in the future.
This paper is focused on meeting the demands for better detection and evaluation of the spinal deformities that go beyond a basic static 3D analysis. It is expected that by observing the spine while ...it moves an improved 3D deformity analysis and measurements can be achieved. In this paper, we present a novel approach for the automatic back symmetry curve sensing. Our approach can be used in the back shape analysis of many different positions, i.e. segments of the dynamic motion, and is not limited only to the upright standing position. The proposed method is based on the 3D surface reconstruction, surface curvature analysis and graph theoretic approach for the (semi-)automatic detection of the symmetry curve. In addition, we introduce a 3D scanning system which was used in our experiment to successfully generate 3D back surface reconstructions for each frame of the captured forward bending motion. We also tested the proposed method on the data collected using commercial 3D spine analysis system and the results were comparable. The additional experiment focusing on the dynamic analysis demonstrated that the proposed method can enable further advances in the automatic 3D back surface analysis by tracking the spine position throughout performed movements.
Purpose
The purpose was to investigate the changes of the psoas major muscles (PM) cross-sectional area (CSA) and fat infiltration in the PM and to investigate the association between the morphology ...of the PM and expression of the degenerative changes of lumbar spine in patients with low back pain (LBP).
Methods
T2-weighted scans for measurements of the CSA and analysis of fat infiltration were performed on 42 patients and 49 controls using a 1.5 Tesla MR system. For a quantitative analysis of fat tissue infiltration a 4-grade visual scale was used.
Results
Patients had bigger CSA of the PM than controls at the levels of L3/L4 and L4/L5 intervertebral disc (
P
< 0.05). Patients with apparent degenerative changes of the lumbar spine had smaller CSA of the PM compared to the patients without apparent changes at the levels of L3/L4 and L4/L5 (
P
< 0.05). At the levels of L4/L5 and L5/S1 patients with present Modic changes in the lumbar vertebral bodies showed smaller CSA of the PM compared to the patients without Modic changes (
P
< 0.05). However, CSA of the PM in the patients with degenerative changes of lumbar spine and Modic changes was still bigger than the one of the controls. At all analyzed levels correlation between CSAs of the PM and fat infiltration of the lumbar paraspinal muscles was negative.
Conclusion
Results suggest increased activity of the PM in LBP patients but PM also remains active regardless of the presence of degenerative and Modic changes of the lumbar spine.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Background: Physical inactivity and sedentary behavior are associated with poor well-being in young people with adverse effects extending into adulthood. To date, there are many studies investigating ...the relationship between physical activity (PA) and posture, but there are no data on the relationship between the type and intensity of PA and sedentary behavior, their association with thoracic and lumbar spine angles, and with endurance and balance of the trunk muscles, especially in healthy young adults aged 18–25 years. Moreover, there are no data on the relationship between PA and sedentary behavior and musculoskeletal and cardiopulmonary health, as well as quality of life (QoL) and sleep that would provide a more comprehensive picture of physical health status. Aim: Therefore, the aim of this cross-sectional study was to investigate the extent to which PA and sedentary behavior are associated with each other and with changes in spinal curvatures, endurance and balance of trunk muscles in an extended analysis of physical health status in young adults aged 18–25 years by additionally including measures of body composition, cardiorespiratory capacity, and QoL and sleep. Methods: A total of 82 students (58% female, 42% male) aged 18–25 years completed all required tests. Primary outcome measures included the following: PA and sedentary behavior calculated from the long form of International PA Questionnaire (IPAQ-LF), spinal curvatures measured by a Spinal Mouse® device, endurance and balance of the trunk muscles measured using trunk endurance tests and their ratio. Results: Overall, 50% of students were classified as minimally active and 50% as health-enhancing PA (HEPA) active. The angles of thoracic kyphosis and lumbar lordosis showed no correlation with PA or time spent sitting. However, students with the lowest PA had significantly higher scores on the trunk extensor endurance test and trunk extensor/flexor endurance test ratio, indicating imbalanced trunk muscles. Moreover, these students spent the most their time sitting. Only PA of vigorous intensity and PA during recreation, leisure, and sports significantly correlated with QoL related to physical health. QoL related to physical and psychosocial health had significantly higher scores when students spent less time sitting. In addition, we found significantly better respiratory performance and SQ at higher PA values, i.e., PA during recreation, leisure, and sport. Conclusions: Our results suggest that students with low PA levels and more time spent sitting have imbalanced trunk muscles, worse respiratory function, and poorer QoL and sleep. Moreover, these findings in college students may reflect their lifestyle and suggest that more PA needs to be promoted to prevent the development of chronic diseases including musculoskeletal disorders.
The purpose of this study was to examine the kinematic and kinetic differences of the sprint start and first two steps between faster and slower high-level sprinters. Twelve male sprinters were ...dichotomized according to personal best 60- and 100-m times. Each participant performed five starts under constant conditions. An eight-camera system was used for 3-D kinematic analysis. Dynamic forces at the start were determined with starting blocks mounted on bipedal force plates. Measures of front and rear block total force, front and rear block maximal force, time to front and rear block peak force, total force impulse, total horizontal and vertical impulse, front and rear block force impulse, time of block clearance, block leaving velocity and block leaving acceleration were collected. Between-group comparisons were made using independent samples t tests (p < 0.05) and by calculating effect sizes (Cohen’s d). Spearman’s correlation coefficients were used to examine the relationships between sprint start kinematics, kinetic measures and sprint performance. Significant between-group differences were observed in rear block total force (p = 0.0059), rear block maximal vertical force (p = 0.0037) and total force impulse (p = 0.0493). Only front block total force significantly correlated with 100 m sprint performance in both the slower and faster groups (r = 0.94 and 0.54, respectively; p = 0.05). Our findings suggest that faster sprinters show enhanced sprint start motor performance with greater force development than slower sprinters.
Nespecifična križobolja (NK) predstavlja značajni zdravstveni i socijalno-ekonomski problem zbog svoje velike učestalosti, dugotrajnosti smetnji, rekurentnosti te funkcionalne i radne ograničenosti ...oboljelih. Čest izostanak određivanja uzroka križobolje i slaba korelacija kliničke slike i dijagnostike pomoću slikovnih prikaza, prvenstveno magnetske rezonancije i rendgena ukazuju na potrebu funkcionalnih mjerenja u pacijenata s NK-om. Funkcionalna mjerenja omogućavaju kvantitativno mjerenje funkcionalnih promjena koje mogu biti uzrokom i posljedicom NK-a te razlogom rekurentnosti i radne ograničenosti. Na temelju podataka funkcionalne procjene mogu se programirati i planirati postupci prevencije NK-a te individualizirati terapijski i rehabilitacijski postupci. Isto tako, funkcionalna mjerenja tijekom liječenja i rehabilitacije omogućavaju praćenje učinkovitosti pojedinih postupaka, a po završetku rehabilitacije i procjenu radne sposobnosti. Premda je značaj funkcionalnih mjerenja za uspješnost rehabilitacije pacijenata s NK-om nedvojben, ne postoji konsenzus o standardizaciji protokola funkcionalnih mjerenja. Definiranje valjanih protokola predstavlja nužnost i važna je pretpostavka uspješnog izlječenja, prevencije rekurentnosti i razvoja kroniciteta nespecifične križobolje.
Handgrip strength is a good general indicator of physical fitness. It has long been used as a diagnostic tool, the results of which are related to eating habits, rotator cuff weakness, fatigue, and ...general physical fitness. We did not find any research of correlation of handgrip with the jumping force, so we wanted to test this in our study. We expected correlations between these two areas of power. The study included vertical and horizontal plyometric jumps, handgrip strength, and some body characteristics. Relationships were verified by correlation analysis. The study included 64 students of the Faculty of Sport, who performed 9 plyometric tests, a handgrip test, and measurements of body characteristics. The results in the participants show the dominance of the right hand and a significant correlation between the strength of the handgrip and body weight. Plyometric jumps show large differences between men and women. In men, there was only the significant correlation of handgrip strength with the test standing triple jump (HG_L/STJ: r=0.33; HG_R/STJ: r=0.35). In women, the force of the handgrip is correlated with the standing triple jump (HG_L/STJ: r=- 0.57; HG_R/STJ: r=-0.55) and horizontal jumps on one leg (HG_L/HJOL_L: r=0.60; HG_R/HJOL_L: r=0.56; HG_L/HJOL_R: r=0.62; HG_R/HJOL_R: r=0.58). Handgrip strength is only correlated with some plyometric jumps. Small number of correlations is most likely due to large differences in neuromuscular mechanisms, as handgrip involves isometric, absolute strength, and plyometric jumps involve relative strength, where subjects must overcome their own body weight. However, it is also necessary to consider the low number of subjects, especially female, which reduced the variability of the sample and the possibility of generalization to the wider population. As expected, of the body characteristics, body weight is most correlated to the handgrip strength.
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