Knee Height Research Articles

Mismatch between fixed classroom furniture and anthropometric measurements among university students: Relationships to ergonomic risk.

Appropriate arrangement of classroom ergonomics is necessary for maintaining health and improving academic performance, learning, and motivation. We aimed to determine the anthropometric measurements and ergonomic risk levels of students during a handwriting activity on a fixed desk and chair and to analyze the mismatch and relationships between these factors. This study included 149 university students (female:73, male:76). Anthropometric measurements (lower and upper extremity length, shoulder height, elbow-rest height, hip-popliteal length, popliteal height, knee height, the distance between tragus and wall, and between acromion and wall) were done with a tape measure. The Rapid Upper Limb Assessment (RULA) tool was conducted to determine the ergonomic risk level while students wrote a standard text on a fixed desk and chair as if they were taking notes in the classroom. The mismatch was evaluated between backrest height and sitting shoulder height, seat height, and popliteal height. The Pearson Chi-Square and the Spearman Correlation test were used for statistical analysis. The median values of the participants' age, height, weight, and BMI were 22 years, 1.70 m, 68 kg, and 23.18 kg/cm2, respectively. Most students had inadequate ergonomic posture while writing on fixed furniture at the university (Median RULA grand score: 4). More mismatches for seat height (54.4%) were found in high ergonomic risk levels but mismatches for backrest height did not follow a similar result. More investigation should be conducted with prospective studies including interventions like adjustable furniture.

Weight, height, waist circumference: association with knee osteoarthritis findings from the osteoarthritis initiative.

Global prevalence of knee osteoarthritis is more than 300 million. Uncontrollable risk factors include age, sex, and height. Controllable risk factors include trauma, weight, and waist circumference. Our goal was to determine the association between knee osteoarthritis and anthropometric measures that include weight, height, and waist circumference. Using 4,602 participants (45-79 years) from the Osteoarthritis Initiative, we analyzed the association between knee osteoarthritis and anthropometry collectively and by sex. We calculated female and male tertiles (3 groups) for anthropometry. Anthropometric measures were correlated with knee osteoarthritis (P ≤ 0.05) except the correlation between height and activities and height and quality of life. When comparing female weight tertiles, there were associations (P's < 0.001) between knee osteoarthritis and weight, but when comparing male weight tertiles, these associations were primarily between the lowest weight and highest weight groups. There were significant associations between knee osteoarthritis and height among female tertiles, with no differences among male tertiles. There were knee osteoarthritis/waist circumference tertile associations (P's < 0.001) for the lowest and highest waist circumference groups. Higher weight in female participants was a stronger predictor of increases in knee osteoarthritis discomforts when compared to waist circumference, while weight and waist circumference were almost equivalent in predicting increases in knee osteoarthritis for male participants. Height did not predict increases in knee osteoarthritis with the exception of female symptoms and quality of life. Quality of life for both sexes was the most unfavorable with female participants reporting a more unfavorable quality of life than male participants.

Tall and Fall Versus Drop and Drive Strategy in College Baseball Pitchers for Velocity and Elbow Valgus Torque

Background: Depending on anthropometrics and coaching style, pitchers are taught to pitch with a stride strategy that are traditionally classified as “tall and fall” or “drop and drive” for the purpose of maximizing pitch velocity. Purpose/Hypothesis: The purpose of this study was to determine the effects of stride strategy (tall and fall vs drop and drive) in college baseball pitching on pitch velocity and elbow valgus torque. It was hypothesized that pitch velocity and elbow valgus torque would increase as pitchers aligned more with the tall and fall technique. Study Design: Controlled laboratory study. Methods: Markerless motion capture data were recorded on 64 collegiate pitchers (height, 1.89 ± 0.06 m; weight, 93.06 ± 9.44 kg) during game play at the host institution during the 2023 season. Peak magnitudes of body center of mass (COM) vertical displacement were determined using a straight-line trajectory between peak knee height and lead foot contact and used as a continuous variable. Pitchers were required to throw ≥4 fastballs during their outing to be included in the analysis. Multilevel modeling was used to determine associations between peak magnitudes of positive and negative vertical displacement of COM on pitch velocity and elbow valgus torque. Every fastball throughout the season with biomechanics data for each pitcher was included in the multilevel model. Results: Fastball velocity was mean ± SD 90.68 ± 2.90 mph (40.54 ± 1.29 m/s). Mean maximal negative vertical COM displacement was −0.91 ± 0.47 inches (−0.023 ± 0.012 m), which occurred 18.1% ± 5.75% of the way between peak knee height and stride foot contact. Mean maximal positive vertical COM displacement was 1.73 ± 1.14 inches (0.044 ± 0.029 m), which occurred 65.7% ± 7.8% of the time from peak knee height to stride foot contact. Positive COM displacement (β = 0.54; P < .001) and timing of peak positive COM displacement (β = 1.82; P = .023) reduced interpitcher variance by 9.9% and improved the ability of our model to predict fastball velocity. Negative COM displacement improved the ability of our model to predict ball velocity (β = −0.45; P = .021). Vertical COM displacement did not influence elbow valgus torque. Conclusion: Increasing vertical COM displacement in either the positive or the negative direction resulted in increased fastball velocity but did not result in greater elbow valgus torque. This indicates that the stride method may be used for performance enhancement but is unlikely to influence ulnar collateral ligament injury risk in college baseball pitchers. Clinical Relevance: Clinicians should not use stride mechanics as an injury risk indicator or diagnostic factor in injury etiology for college baseball pitchers.

Stature estimation in male and female populations of India and Nigeria depending on other anthropometric parameters using multiple regression analysis

In cases of mass disasters, accidents, or criminal investigations where the identity of victims is unknown certain basic anthropological parameters are helpful in ascertaining these like race, sex, age and stature. Estimating stature using multiple body measurements such as shoulder breadth, foot length, thigh length, and knee height is a common approach in anthropometry and forensic anthropology. The presence of sex and population differences in anthropometric indicators allows these measurements to be used not only to estimate the stature of an individual, but also to determine sex, different races or populations based on skeletal remains. The purpose of the study is to develop and practically verify the work of regression equations for estimating stature depending on other anthropometric indicators of men and women of two ethnically diverse populations. For this study, anthropometric data were gathered from two distinct population groups: Indian (n=102) and Nigerian (n=205). Basic demographic details along with measurements of shoulder breadth, sitting shoulder height, sitting foot length, sitting knee height, and sitting thigh length were obtained using standardized techniques as per the established anthropometric protocols. Statistical analysis was performed using appropriate software packages such as SPSS, R, or SAS. The multiple regression method was used to estimate body length depending on other anthropometric indicators. As a result of the conducted multiple linear regression analysis, reliable relationships between stature and specific anthropometric measurements in Nigerian and Indian men and women were established. It was found that stature is highly likely to depend on knee height in a sitting position in Nigerian women (R2=0.531, p&lt;0.001), as well as hip length, foot length, and shoulder height in a sitting position in Indian men (R2=0.725, p &lt;0.001). Stature in Indian women reliably depends on hip length and foot length in a sitting position, and in Nigerian men - on hip length, foot length, shoulder width and shoulder height in a sitting position, but the regression equations have a coefficient of determination less than 0.5 (respectively, R2=0.463, p&lt;0.001 and R2=0.405, p&lt;0.001) and therefore do not have much significance for forensic purposes. Additional groups (30 people for each category) were used to test the obtained regression equations. The high correlation coefficients (0.6&lt;r&lt;0.75) observed in both test groups indicate the reliability of the regression models and the suitability of the selected anthropometric measurements for the estimation of stature in these populations. The obtained data emphasize the importance of taking into account factors specific to the population when developing regression equations for the estimation of stature and emphasize the usefulness of anthropometric measurements in predicting this indicator for different gender and demographic groups of the population, although their further verification on larger and more diverse samples is necessary.

Association of Hemogram Parameters with Body Mass Index in Knee Osteoarthritis

Objective: This study aims to investigate the relationship between hemogram parameters, which are low-cost, easy, routinely applied low-grade inflammation indicators, and severity of knee osteoarthritis (KOA) and obesity. Materials and Methods: This study involved 140 KOA patients aged 45 to 85 who underwent knee radiographs, weight and height measurements, and routine laboratory tests. Recorded data included demographic information (gender, age), body mass index (BMI), routine hemogram, and laboratory parameters. Patients were categorized into two groups based on their Kellgren-Lawrence (KL) scores (mild: KL 1-3, severe: KL 4) and four groups according to their BMI (BMI 35). Results: The findings revealed significantly elevated levels of serum Neutrophil-to-Lymphocyte Ratio (NLR) and C-reactive protein (CRP) in severe KOA compared to mild KOA (P30 in mild KOA groups, while mean blood NLR was notably higher in patients with BMI=30-35 in severe KOA groups. Conclusions: These results suggest that NLR and NMR could provide a new perspective on the relationship between obesity and mild KOA in clinical practice, presenting a cost-effective and easily applicable alternative for determining disease prognosis and progression.

Influence of brick laying height on biomechanical load in masons: Cross-sectional field study with technical measurements.

Work-related musculoskeletal disorders (WMSDs) located in the low back and neck/shoulder regions are major concerns for both workers, workplaces, and society. Masons are prone to WMSD, because their work is characterized by repetitive work and high physical workload. However, the knowledge on the physical workload during bricklaying is primarily based on subjective measurements. This cross-sectional field study with technical measurements aimed to quantify physical workload in terms of muscular activity and degree of forward bending during bricklaying at different working heights among masons, i.e., knee, hip, shoulder, and above shoulder height. Twelve male (36.1±16.1 years) experienced masons participated in a cross-sectional field study with technical measurements. Surface electromyography from erector spinae longissimus and upper trapezius muscles and an inertial measurement unit-sensor placed on the upper back were used to assess the physical workload (level of muscle activation and degree of forward bending) different bricklaying heights. Manual video analysis was used to determine duration of work tasks, frequency, type, and working height. The working heights were categorized as 'knee', 'hip', 'shoulder', and 'above shoulder'. The 95 percentiles of the normalized Root Mean Square (RMSn) values were extracted assess from erector spinae and trapezius recordings to assess strenuous level muscle of muscle activation. The RMSn of dominant erector spinae muscle increased from hip- to shoulder height (from 26.6 to 29.6, P < 0.0001), but not from hip to above shoulder height and decreased from hip to knee height (from 26.6 to 18.9, P < 0.0001). For the dominant trapezius muscle, the RMSn increased from hip- to shoulder- and above shoulder height (from 13.9 to 19.7 and 24.0, respectively, P < 0.0001) but decreased from hip- to knee height (from 13.9 to 11.5, P < 0.0001). Compared to hip height (27.9°), an increased forward bending was detected during bricklaying at knee height (34.5°, P < 0.0001) and a decreased degree of forward bending at shoulder- and above shoulder height (17.6° and 12.5°, P < 0.0001, respectively). Based on technical measurements, bricklaying at hip height showed the best compromise between muscular load and degree of forward bending. This study contributes to the development of the work environment for masons and can help guide preventive initiatives to reduce physical workload.

Professional baseball pitchers produce similar ball velocity and kinematics when pitching from the wind-up and stretch deliveries: a biomechanical analysis

ABSTRACT Historically, the wind-up delivery is considered a more biomechanically advantageous pitching motion compared to the stretch. Recently, some pitchers have shifted to pitching exclusively from the stretch regardless of the game situation. The goal of this study was to compare temporal, kinematic and kinetic variables between the wind-up and stretch deliveries. Professional pitchers (n = 52, 189.1 ± 4.8 cm, 92.8 ± 8.4 kg) threw fastballs evaluated by 3D-motion capture (480 Hz) from both the wind-up and stretch deliveries. Within a pitcher, there was no significant difference in ball velocity between the two deliveries (p = 0.15). The stretch delivery was significantly quicker to ball release at toe off 2 (p < 0.001) (the last frame the pitcher’s foot contacts the ground before progressing to maximum knee height) and maximum knee height (p < 0.001). The majority of differences occurred prior to foot contact. The wind-up delivery produced greater maximum shoulder external rotation (p < 0.001) and lead knee flexion at ball release (p < 0.001). Pitching from the stretch incurred greater shoulder superior force (p < 0.001). It remains unknown if this is clinically significant as pooled means show only a 2% difference. Therefore, pitching a fastball from either the wind-up or stretch delivery provides comparable mechanics and throwing arm load with likely comparable risk of injury.

Growth Parameters and Protein Content of Maize as Influenced by Sowing Methods and Different Levels of Nitrogen

The field experiment was carried out at Research Farm, Integral University, Lucknow, Uttar Pradesh, India during Kharif season, 2021. The experiment envisages to study the effect of Sowing methods and different Nitrogen levels on yield and attributes of maize crop. The experiment was laid down in the Split Plot Design and the treatments were replicated three times. The maximum plant height of 56.92 cm, 235.17 cm and 237.16 cm was observed in the ridge method of sowing at knee height stage, tasselling stage and at harvest stage, respectively. Among nitrogen levels, the maximum plant height of 57.61 cm, 235.29 cm and 238.38 cm was observed at knee height stage, tasselling stage and at harvest stage, respectively in the treatment (N5) 25% N through granular urea + 75% N through Nano-urea. Among nitrogen levels, the maximum DMA of 86.30, 425.36 and 1287.73 g sqm-1 day-1 was observed at knee height stage, tasselling stage and at harvest stage, respectively in the treatment (N5) 25% N through granular urea + 75% N through Nano-urea. At harvest stage number of leaves per plant were highest in the S1 (14.33) and N5 (16.13) treatment. Among nitrogen levels, the maximum leaf area index (LAI) of 1.55, 2.49 and 1.9 was observed at knee height stage, tasselling stage and at harvest stage, respectively in the treatment N5. Among sowing methods, highest protein content was found in the ridge method (10.14%) followed by flat method (9.81%) and broadcast method (9.42%) of sowing. The protein yielded maximum of 586.15 kg ha-1 in the N5 treatment. All parameters showed better in granular urea application rather than nano-urea, when used solely.

A LiDAR-Based Recommendation System to Improve Sitting Posture Respecting Privacy.

Poor posture is becoming more widespread due to the rising number of jobs that require workers to sit for extended hours. Maintaining proper leg positioning is essential for good overall posture and long-term health. However, current monitoring methods involve multiple sensors and cameras, leading to discomfort and privacy concerns. This paper presents a privacy-preserving recommendation system using Light Detection and Ranging (LiDAR) to monitor leg positions. The system captures the horizontal leg outline at knee height and extracts domain-specific features, while a stacked autoencoder reproduces the latent representation of the leg outline. The system comprises three modules, including one-class and multi-class support vector machines, to identify 15 leg positions and reject unrecognized ones. Data from 30 healthy volunteers during work activities trained the system. When tested on new participants, the system achieved an accuracy of over 98%. In addition to monitoring leg positions while respecting privacy and ergonomics, our system alerts workers about poor leg positions and generates intuitive dashboards with posture statistics that help safety engineers identify at-risk workers and body parts. This offers a promising solution for improving desk workers' posture and reducing long-term health issues, respecting privacy.

The correlation between ball velocity with hip-shoulder rotation and separation during pitching process in baseball pitchers

&lt;p&gt;目的：本研究欲探討成棒選手肩髖的旋轉及肩髖分離程度與球速間的相關性，用以尋找提升球速的方法。方法：以 18 位大專公開一級棒球投手作為研究參與者，同時利用慣性感測 (IMU)、二維影像分析系統及測速槍測量研究參與者之投球運動學參數，包括肩與骨盆在各時間點的旋轉角度、肩髖分離的角度、旋轉峰值時機及球速等。以皮爾森積差相關係數分析肩與骨盆的旋轉情況及肩髖分離程度與球速之間是否具有相關性。結果：本研究顯示除了上軀幹在膝蓋最高點 (r =-.295, p =.441)外，其餘分別為上軀幹在前導腳落地時 (r = -.821, p &lt; .001)、上軀幹在球離手時 (r = .765, p = .016)、骨盆在膝蓋最高點時 (r = -.791, p = .011)、骨盆在前導腳落地時 (r = .906, p= .001)、骨盆在球離手時 (r = .951, p &lt; .001)，都與球速呈顯著相關；上軀幹與骨盆的旋轉速度峰值、時機與球速呈顯著相關 (r = .934, p &lt; .001)、(r = .969, p &lt; .001)、(r = .881, p = .002)、(r = -.749, p = .02)；肩髖分離程度與上軀幹和骨盆的旋轉及球速皆呈顯著相關。結論：本研究顯示不僅是上軀幹，骨盆的旋轉與球速也息息相關，因此在投球動作上應注重投球動作的整體性，而非強調單一肢段的發力，且若能同時妥善運用肩髖分離，則能提升運動表現。&lt;/p&gt; &lt;p&gt;&amp;nbsp;&lt;/p&gt;&lt;p&gt;Purpose: This study aims to investigate the correlation between hip-shoulder and separation degree with ball speed in skilled baseball pitchers to identify methods for enhancing pitching velocity. Methods: Eighteen collegiate level-Ⅰbaseball pitchers participated as research subjects. An inertial measurement unit (IMU), a two-dimensional motion analysis system, and a radar gun were employed to measure the kinematic parameters of the pitching motion. These parameters included rotational angles of the shoulder and pelvic at various time points, the degree of hip-shoulder separation, peak rotation timing, and ball velocity. Pearson correlation coefficients between ball velocity, hip shoulder separation, and all trunk and pelvic kinematic variables were computed, and the level of significance was set at &amp;alpha; = .05. Results: The results indicate that, except for the upper trunk at the maximum knee height(r = -.295, p = .441), the rest were significantly related with ball velocity: the upper trunk at the landing of the leading foot (r = -.821, p&lt; .001), the upper trunk at the ball off hand (r = .765, p = .016), the pelvic at the maximum knee height (r = -.791, p = .011), the pelvic at the landing of the leading foot (r = .906, p = .001), and the pelvic at the ball off hand (r = .951, p &lt; .001). The peak rotation velocity and the timing of the peak rotation velocity of the upper trunk and pelvic is also significantly related to ball velocity(r = .934, p &lt; .001)、(r = .969, p &lt; .001)、(r = .881, p = .002)、(r = -.749, p = .02). The degree of shoulder-hip separation is significantly correlated with the rotation of the upper trunk and pelvic and ball velocity. Conclusion: Based on the findings of this study, we know the significance of not only the upper trunk but also pelvic rotation with ball velocity. Therefore, a holistic approach to pitching mechanics, emphasizing overall motion rather than isolating individual segments, is crucial. Additionally, effectively utilizing hip-shoulder separation can enhance overall athletic performance in baseball pitching.&lt;/p&gt; &lt;p&gt;&amp;nbsp;&lt;/p&gt;

High-intensity resistance training and collagen supplementation improve patellar tendon adaptations in professional female soccer athletes.

We investigated whether 10 weeks of pre-season soccer training (including high-intensity resistance exercise) with hydrolysed collagen (COL) supplementation would confer greater changes in patellar tendon (PT) mechanical and material properties compared with placebo (PLA) in professional female soccer athletes. Eleven athletes from the first team squad of a Football Association Women's Championship soccer club volunteered to participate in this study (age, 25.7±4.2 years; height, 1.68±0.04m; mass, 64.0±4.6kg). Participants were pair-matched for baseline knee extensor maximum isometric voluntary contraction torque, age, height and mass and were randomly assigned to the COL group (n=6) or PLA group (n=5). Participants were given 30g COL or energy-matched (36.5g maltodextrin and 8.4g fructose) PLA, plus 500mg vitamin C before each training session, which consisted of high-intensity lower-limb resistance exercise, plyometric or pitch-based exercise 3 days/week for 10weeks during the pre-season period. We assessed knee extensor maximum isometric voluntary contraction torque and PT properties using isokinetic dynamometry and ultrasonography before and after the intervention. The PT stiffness [COL, +15.4%±3.1% (d=0.81) vs. PLA, +4.6%±3.0% (d=0.32), P=0.002] and Young's modulus [COL, +14.2%±4.0% (d=0.65) vs. PLA, +3.4%±2.8% (d=0.15), P=0.004] increased more in COL than in PLA. There was a main effect of training on PT cross-sectional area (P=0.027), but no interaction effect (P=0.934). To conclude, 10 weeks of pre-season soccer training (incorporating high-intensity resistance exercise) with 30g COL increased PT stiffness and Young's modulus more than training alone in professional female soccer athletes. This has positive implications for improving athletic performance and mitigating injury risk.

Response of Maize (&amp;lt;i&amp;gt;Zea may&amp;lt;/i&amp;gt; &amp;lt;I&amp;gt;L.&amp;lt;/I&amp;gt;) Cultivars to Urea Time Application on Phenology, Growth and Grain Yield at Bako, East Wollaga, Ethiopia

The results of this research provide a basis for additional exploration and advancement, which will culminate in suggestions for the timing of split urea treatment and cultivars for sustainable maize production within the study region. During the 2019 and 2020 growing seasons, a field experiment was conducted at the Bako Agricultural Research Center to determine the response of hybrid maize cultivars to urea split application on phenology, growth, and grain production. In the experiment, six levels of urea split application were applied to two types of corn. T1 = 1/2 dose of urea at planting + 1/2 dose of urea at Knee height; T2 = 1/2 dose of urea at planting + 1/2 dose of urea at tasseling; T3 = 1/ 3 dose of urea at planting + 1/3 dose of urea at knee height + 1/3 dose of urea at tasseling; T4 = 2/3 dose of urea at knee height + 1/3 dose of urea at tasseling; T5 = 1/2 dose of urea at knee height + 1/2 dose of urea at tasseling; and T6 = 1/4 dose of urea at planting + 1/2 dose of urea at knee height + 1/4 dose of urea at tasseling. The experiment&amp;apos;s randomized complete block design made use of three replications. The primary effects of the urea split time of application were found to have a substantial impact on plant height, 90% physiological maturity, grain production, total leaf area per plant, and leave area index. Three urea split applications 1/4 dosage at planting, 1/2 dose at knee height, and 1/4 dose at tasseling provided the maximum net benefit of EB 246,536.7 ha-1 and the best marginal rate return of 2822.26% for maize output. In conclusion, urea split application 1/4 doses at planting stage 1/2 dose at knee-height and 1/4 dose at tasseling stage is the best time of application in good rainy seasons and hence recommended for the end users. However, in the case of erratic and heavy rainy seasons, application at three times should be used to get maximum profit and acceptable MRR.

The estimation of different body dimensions of children aged 6-11 years for the needs of furniture designers.

There are some rules that furniture designers must take into consideration to design ergonomic furniture. The main design principle is the target group for which the furniture will be designed, considering the dimensions of people who use the furniture. The paper presents the correlation between 12 parts of children's body, as well as the proportion between stature and 11 other parts of the body which are used for the purposes of furniture and interior designers. Field measurements include: Stature (S), Sitting height (She), Shoulder height (Sh), Popliteal height (Ph), Hip width (Hb), Elbow rest height (Erh), Buttock-popliteal length (Bpl), Buttock-knee length (Bkl), Thigh clearance (Tc), Eye height sitting (Eh), Knee height (Kh) and Shoulder breadth (Sb) to pupils aged 6-11 (grades 1 to 5). The measurements were done in 687 children in 12 primary schools in 4 different regions in Kosovo. The data of the study shows that, in general, there is a correlation (in some parts strong and in some medium) for the measured parts. Also, the study presents the proportion between the stature and other parts of the body which are necessary for the design of children's furniture. Using this data will enable furniture designers to easily target the dimensions of the group they will design, even by measuring only one dimension, i.e. stature and then setting the proportions for each piece separately.

Comparison of predictive accuracy of knee height equations in children.

Knee height can be a proxy for height when standing height cannot be reliably measured. We compared two commonly used equations (Chumlea and Rumapea) that estimate standing height from knee height. We prospectively enrolled 210 children without scoliosis or kyphosis aged 7-12 years (mean age: 10.2 years, 47.6% males) and measured their knee heights and standing heights. A two-tailedT-test was used to compare predicted heights from each of the equations to actual standing height. Chumlea equation was found to be unreliable (p = 0.0376) while Rumapea equation was found to be reliable in estimating standing height (p = 0.878). Additionally, Rumapea equation was also found to be more accurate than Chumlea equation when results were segregated based on gender and race. In conclusion, the Rumapea equation yields more accurate estimates of standing heights than the Chumlea equation in US children aged 7-12 years.

The Accuracy of Height Prediction Equations in Greek Patients: A Cross-Sectional Study.

In clinical settings, standing height measurement is often difficult to perform due to patients' inability to stand upright. Height prediction equations derived from measurements of the length of other body segments have been published; however, they are not readily applicable to all populations since ethnic differences affect the relationship between standing height and body segment length. This cross-sectional study aimed to examine the accuracy of height prediction using the Malnutrition Universal Screening Tool (MUST) height predictive equations among Greek patients and to develop new, nationally representative equations. The study population consisted of 1198 Greek adult outpatients able to stand upright without assistance and without medical conditions that affected their height. Standing height, ulna length, knee height and demi-span measurements were obtained from 599 males and 599 females. Patients were stratified into age groups of <55 and ≥55 years, <60 and ≥60 years and <65 and ≥65 years according to the categories indicated by the MUST for height prediction from alternative measurements. There were positive correlations between standing height and ulna length and knee height and demi-span length (p < 0.001) in both sexes and all age categories. A strong correlation was observed between the measured and predicted standing height using ulna length (rho = 0.870, p < 0.001), knee height (rho = 0.923, p < 0.001) and demi-span length (rho = 0.906, p < 0.001). The average difference between the MUST indicative equations' height predictions from alternative measurements and actual height was -3.04 (-3.32, -2.76), -1.21 (-1.43, -0.988) and 2.16 (1.92, 2.41), respectively. New height prediction equations for Greek patients were identified, with the predicted values closer to the measured standing heights than those predicted with the MUST indicative equations for height prediction from alternative measurements.

The effect of the conventional deadlift and Romanian deadlift on muscle activation and joint angles at submaximal intensity

For fitness professionals delivering strength and conditioning programmes and recreational athletes designing their own programmes, exercise selection and an appropriate loading stimulus over time are the cornerstones of an effective resistance training programme. The conventional deadlift (CD), a compound, closed-chain movement, is prescribed to increase the strength of the posterior chain and the quadriceps. The Romanian Deadlift (RDL) is an isolated knee variation of the CD, whereby the knee angle is stable throughout the movement (Lee et al., 2018, J Exer Sci Fit, 16, 87-93). The RDL is a key movement in weightlifting training and is a commonly used developer of posterior chain muscles (Weaver and Kerksick, 2017, Strength Cond J, 39, 85-90). Studies comparing the CD and RDL are limited. Using surface EMG 2D motion analysis of the lower limb, we aim to determine if (i) biceps femoris activation is greater than the vastus lateralis during the RDL, (ii) there is a higher activation of both vastus lateralis and biceps femoris during the CD, and (ii) whether an injury is more likely to occur during a CD or RDL using the angles and range of motion (ROM) of the hip, knee, and ankle. 15 recreationally active adults with experience with the CD and RDL were recruited. Surface EMG sensors were placed on the vastus lateralis and biceps femoris, and markers were placed for 2D motion analysis in the sagittal plane. MVC data were collected for three repetitions of both lifts at 70% RDL 1RM. Five repetitions at 50% RDL 1RM were used for analysis. Statistical analysis was conducted using a paired t-test and Wilcoxon signed-rank test. The results show greater activation of the vastus lateralis in the CD than the RDL (P &lt; 0.05) but no difference in the biceps femoris. No differences were found in hip angles during ascent or descent at mid-thigh and knee height (P = 0.343), but there were differences at the bottom position. Knee angles during ascent and descent at the mid-thigh were different (P = 0.027) but not at knee height. No differences at the ankle joint were found at the mid-thigh (P = 0.12), but differences were found at knee height and bottom position. Finally, ROM at the hip, knee, and ankle during ascent and descent were significantly different (P = 0.002). The findings may help fitness professionals and recreational athletes make decisions such as exercise selection, load management, and injury prevention strategies based on the comparative effectiveness and risks of the CD and RDL.

Application of Multiple Linear Regression Analysis in Ergonomics Study for Public Institution Seat W idth

Objectives: To determine minimum seat width of comfortable seating for adult population, using multiple linear regression analysis on chair leg thickness, chair leg width, chair apron width, and knee height. Methods: Dimensions of three (3) factors were recorded using 310 adult workers. Multiple linear regression was used for statistical analysis for understanding how multiple factors (like chair leg thickness, chair leg width, chair apron width, and knee height) influence a single outcome to enhance comfortable seating. The collected data (chair leg thickness, chair leg width, chair apron width, and knee height) was analysed with the help of the analysis tool. Findings: The analysis used four predictors (knee height, chair leg thickness, chair leg width, and chair apron width) to obtain one predicted variable (seat width) to achieve comfortable seating based on these measurements. Subsequently, a moderate correlation existed between predictors and predicted variables, while correlations between predictors were less than 0.7 for them to be retained in the model. The coefficient of determination ( ) is 0.3003, indicating that 30.03% of the variance in predictors could be explained by seat width. Based on the comfort assessment and analysis results, required widths that ensure comfortable seating for the target population can be recommended in public institutions. Overall, this research has the potential to improve public health, comfort, and productivity by creating data-driven design standards for seating in public institutions. Novelty: The study focused on elderly workers who patronise this furniture in the administration block of public institutions. Keywords: Multiple linear regression, Ergonomics, Knee height, Chair component dimensions, Seat width

The Effect of Knee Height Asymmetry on Gait Biomechanics.

Though the primary goal for limb length discrepancy (LLD) management is to equalize the leg lengths, symmetry between corresponding long bones is usually not achieved, leading to knee height asymmetry (KHA). To date, there is minimal information on what effect KHA has on gait biomechanics and joint loading. Thus, the purpose of this study is to determine the impact of KHA on gait biomechanics. Seventeen subjects with KHA after limb equalizing surgery and 10 healthy controls were enrolled. Subjects participated in 3D gait analysis collected using self-selected speed. Lower extremity kinematics, kinetics, work generated/absorbed, and total work were calculated. Standing lower limb x-rays and scanograms were used to measure LLD and calculate the tibia-to-femur (TF) ratio for each limb. Two sample t tests were used to compare differences in standing LLD, TF ratio, and work between groups. Bivariate correlation using Pearson correlation coefficients was conducted between TF ratio and total mechanical work, as well as between knee height asymmetry indices and total work asymmetry (α=0.05). Among participants, there were no differences between LLD; however, there were differences between TF ratio and knee height asymmetry. We found a nonsignificant relationship between TF ratio and total mechanical work for individual lower extremities. Therefore, the length of individual bones (TF ratio) relative to each other within the individual lower extremity was not associated with the amount of work produced. However, when a difference exists between sides (asymmetry, ie, TF ratio asymmetry), there were associated differences in work (work asymmetry) produced between sides (r=0.54, P =0.003). In other words, greater knee height asymmetry between limbs resulted in more asymmetrical mechanical work during walking. These findings may have implications for the management of LLD. Asymmetrical total mechanical work could lead to atypical joint loading during gait. Surgeons may want to consider prioritizing achieving knee height symmetry as a postoperative goal when correcting limb length discrepancy. Level III, Case Control Study.

Comparison of Windup and Stretch Pitching Biomechanics in Baseball With Implications for Safety and Performance

Background: Historically, it was assumed by some that high leg lift with windup pitching generated more ball velocity whereas pitching from the stretch was quicker to reduce the risk of base stealing but also more stressful on the arm. However, many now believe that velocity and stress do not differ between windup and stretch and always pitching from the stretch is simpler than mastering 2 techniques. Purpose/Hypothesis: The purpose of this study was to compare windup and stretch fastball pitching biomechanics. It was hypothesized that there would be statistically significant and clinically important differences in ball velocity, timing of angular velocities, joint kinetics, and pitching kinematics. Study Design: Controlled laboratory study. Methods: Fastball pitching biomechanics previously captured for 221 healthy baseball pitchers (105 professional, 52 collegiate, and 64 high school level) were analyzed. For each pitcher, data for 3 to 10 windup trials and 3 to 10 stretch trials were available. Ball velocity was recorded using a radar gun. A 12-camera, 240-Hz automated motion capture system was used to track 39 reflective markers attached to the pitcher. A total of 24 kinematic parameters, 4 temporal parameters, and 5 kinetic parameters were calculated. Data for each parameter were compared across the 2 techniques and 3 competition levels using 2-way repeated-measures analysis of variance (P < .01). Based on previous studies and the expertise of the investigators, the minimal clinically important difference (MCID) was set as 2° for angle measurements, 20 deg/s for angular velocities, 0.5 m/s for fastball velocity, and 0.3% body height × weight for normalized joint torque. Results: Fastball velocity was statistically greater from the windup than stretch for the collegiate subgroup but not for the other 2 levels. The collegiate level difference was below the MCID. Pitching from the windup generated greater front knee height and required more time from initiation of leg lift to front foot contact. From foot contact to ball release, there were 11 additional small, statistically significant differences between windup and stretch; however, each of these was well below the MCID. Conclusion: Pitching from the stretch was quicker and should be used with runners on base to prevent stealing. Pitching from the windup and stretch produced similar ball velocity, joint kinetics, and kinematics. Thus, pitchers may choose to use both techniques or stretch only based on comfort and personal preference. Clinical Relevance: The decision to pitch from both the windup and stretch or only from the stretch should not affect a pitcher's performance or joint stress (and injury risk).

Perancangan Alat Bantu Penghitung Pentol untuk Mempermudah Proses Pengemasan Berdasarkan Antropometri Pekerja

The "Raja Gresik" meatball factory was established in 2008 and was established in 2018. One of the problems at this factory was that when carrying out the process of packaging meatball in plastic packs, there were packs whose quantity did not match the specifications for the number of meatball of that type. With the existing problems, it is hoped that this research can help the "Raja Gresik" meatball factory to reduce defects in calculating meatball in packs and make workers less tired because the design of the meatball counting tool is in accordance with the anthropomometry of workers. The existence of this tool can reduce losses from an inappropriate number of meatballs in the pack, which will effectively prevent product defects from excess or shortage of meatball. Also, the presence of this tool makes the packaging process time faster from 30 seconds to 23.43 seconds after using this tool. And it can be used for worker anthropometry, namely hand reach length, knee height and standing elbow height.