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Optimized design of women’s graduated compression sports leggings
Abstract
In this study, we optimized design of a series of sports leggings O1/O2/O3 with graded pressures, evaluated a mannequin static, four-subjects static and dynamic dressing pressure, and compared with the commercial L-brand sports leggings L1/L2/L3. The results showed that the optimized design sports leggings had lower dressing pressure at the waist, abdomen, and hip than the commercial sports leggings, in which the dressing pressure of a mannequin static, four-subjects static and dynamic at the pressure-significant hip point P8 were reduced by 2.34–14.02%, 16.26–21.78%, and 5.26–11.88%, respectively. The four circumferential directions P4–7, P9–12, P13–16, and P17–20 from the groin to the ankle showed graded pressure trends, while the pressure of commercial sports leggings fluctuated with no significant pattern. In addition, the blood flow of O1/O2/O3 was higher than that of when naked and L1/L2/L3 in both static and dynamic dressing. The blood flow showed a decreasing trend with time, but O1/O2/O3 still had a relatively large blood flow, especially wearing O1 (76.671 PU, 64.054 PU) had a significant dynamic blood flow in both time stages, which had a positive effect on the promotion of blood circulation of the legs. L1/L2/L3 had lower blood flow in the inner calf P15 than when naked, a condition that may inhibit blood flow in the legs and lead to increased fatigue in the human legs, which is detrimental to physical exercise and human health.
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The high-elasticity bottoms applying gradual pressurization to the blood vessels of the lower extremities simultaneously assisting to both prevention and treatment of multiple health conditions such as varicose veins. Medical compression stockings are classified as medical supplies, and there is a clear standard on magnitude and application for gradual pressure. However, in the case of leggings, there are no relevant experimental data or papers supporting these findings. This study was performed in order to analyse the gradual compression values in legging. Eight types of leggings currently available on the market by different brands, were analysed to determine the type of pressure applied. The pressure was measured at five points of the clothed body with leggings pulled across lower extremities. An airpack sensor was attached to a wooden leg model and five consecutive records at each measuring point were taken. Afterwards the average values were calculated. As observed in all eight leggings, the measuring point with the highest pressure applied was the back of the calf (mean 18.25 mmHg) or the below the knee circumference (mean 13.83 mmHg), pointing to deviance in applying gradual pressure as proposed in medical compression stockings. The commercial leggings used in this experiment did not show a gradual increase in pressure from the thigh to the ankle body zone. One can presume that the legs’ fatigue would increase over the time. Since, the gradual pressure should be applied in legging construction as seen in medical compression stockings.
Objectives
Explore the feasibility of lower-limb garment-integrated BFR-training.
Design
Observational study.
Setting
Human performance laboratory.
Participants
Healthy males with no experience of BFR-training.
Main outcome measures
Feasibility was determined by a priori thresholds for recruitment, adherence, and data collection. Safety was determined by measuring BFR torniquet pressure and the incidence of side effects. Efficacy was determined by measuring body anthropometry and knee isokinetic dynamometry. Feasibility and safety outcomes were reported descriptively or as a proportion with 95% confidence intervals (95% CI), with mean change, 95% CIs, and effect sizes for efficacy outcomes.
Results
Twelve participants (mean age 24.8 years [6.5]) were successfully recruited; 11 completed the study. 134/136 sessions were completed (adherence = 98.5%) and 100% of data were collected. There was one event of excessive pain during exercise (0.7%, 95% CI 0.0%, 4.0%), two events of excessive pain post-exercise (1.5%, 95% CI 0.4%, 5.5%), and one event of persistent paraesthesia post-exercise (0.7%, 95% CI 0.0%, 4.0%). Mean maximal BFR torniquet pressure was <200 mmHg. We observed an increase in knee extension peak torque (mean change 12.4 Nm), but no notable changes in body anthropometry.
Conclusions
Lower-limb garment-integrated BFR-training is feasible, has no signal of important harm, and could be used independently.
Sports bras are an essential apparel for active women, but may exert excessive pressure that negatively affects thermoregulation, thermal comfort and wear sensation. This study measures skin temperature changes during short durations of exercise on a treadmill with different bra pressures. The results based on 21 female subjects (age: 27.2 ± 4.5 years old) show that bras with more pressure at the underband or shoulder straps do not cause statistically significant skin temperature changes during exercise (p > 0.05). Nevertheless, compared to the optimal bra fit, significant differences in bra-breast skin temperature are found during running, cooling down and sitting when the bra pressure is increased (p < 0.05), particularly under bra cup (T1) in this study. The FLIR thermal images can visualize the skin temperature changes at abdomen throughout the four activity stages. Subjective sensations of bra thermal comfort, pressure and breast support are assessed. Despite the increased pressure on the shoulders and chest wall, perceptions towards thermal comfort remain unchanged. The perceived pressure comfort and support sensation amongst the 4 bra conditions are comparable. Interestingly, positive sensations of pressure comfort and breast support are perceived with a tight-fitting sports bra during treadmill exercise. High pressures induced by sports bras (>4 kPa) that habitually considered harmful to the human body may not lead to wear discomfort but enhance bra support sensation and a sense of security to the wearers.
Background:
Previous studies have shown that compression garments may aid recovery in acute settings; however, less is known about the long-term use of compression garments (CG) for recovery. This study aimed to assess the influence of wearing CG on changes in physical performance, subjective soreness, and sleep quality over 6 weeks of military training.
Methods:
Fifty-five officer-trainees aged 24 ± 6 y from the New Zealand Defence Force participated in the current study. Twenty-seven participants wore CG every evening for 4-6 h, and twenty-eight wore standard military attire (CON) over a 6-week period. Subjective questionnaires (soreness and sleep quality) were completed weekly, and 2.4 km run time-trial, maximum press-ups, and curl-ups were tested before and after the 6 weeks of military training.
Results:
Repeated measures ANOVA indicated no significant group × time interactions for performance measures (p > 0.05). However, there were small effects in favour of CG over CON for improvements in 2.4 km run times (d = -0.24) and press-ups (d = 0.36), respectively. Subjective soreness also resulted in no significant group × time interaction but displayed small to moderate effects for reduced soreness in favour of CG.
Conclusions:
Though not statistically significant, CG provided small to moderate benefits to muscle-soreness and small benefits to aspects of physical-performance over a 6-week military training regime.
Graduated compression is widely used for medical application to prevent perioperative venous thromboembolism, but other applications such as sportswear can potentially also benefit from it. A tight-fit cycling shirt meant to ensure the correct position during cycling and prevent injuries was designed. The aim of this study was to improve garment pattern design from the aspect of clothing pressure for providing support and enhancing comfort to the user. This paper investigates the suitability of pressure maps from 3D fashion design software CLO 3D for design and in particular its capability to discriminate between various materials and cycling postures. Moreover, the impact of the mechanical properties of fabric was analyzed. In particular, virtual prototyping tool CLO 3D and pressure mapping were employed to achieve the required graduated compression while ensuring fit and comfort. Pattern adjustments were iteratively performed until stress, strain, and pressure maps showed adequate fit and pressure of the cycling garment on the virtual cyclist in static and dynamic cycling positions. The impact of fabric types on garment fit has been shown by generating the stress, strain, and pressure maps with a virtual simulation. It was found that the visualized pressure on the human body model shows distributions that are related to contact between body and garment, and large compression stresses occur in the lower parts of the two shirts. Evident garment deformation was shown at hip level, upper arm, lower front side seam, and front neck, which can reduce garment wear comfort and freedom of movement. The output was found to be sufficiently accurate to optimize the garments based on material and cycling posture.
This paper lays out standards of compression stockings and their classification into classes. The analysis of knitted fabric structure parameters, elongation and compression of moderate- and high-compression stockings was conducted. Stocking compression on specific parts of the stocking leg was measured on three sizes of a wooden leg model. For moderate-compression stockings, compression above the ankle was 32 hPa. For high-compression stockings, compression above the ankle was 60 hPa. Both groups of the analyzed compression stockings were made on modern one-cylinder hosiery automats. The legs of the stockings were made in single inlaid jersey 1 + 1. Both yarns were elastane covered. The finer yarn formed loops and its knitting into a course was significantly larger than in the other yarn, which was much coarser and does not form loops but “lay the weft in a bent way”. The smallest elongation of knitted fabric was above the ankle, where the highest compression was achieved, while the largest elongation was under the crotch, where the stocking leg exerted the smallest compression on the surface. The leg of the compression stocking acted as a casing that imposed compression on the leg and often reinforced it to be able to sustain compression loads.
Osteoarthritis is a chronic disease that affects joint cartilage and can cause severe pain and disability. Minor neglected injuries may also result in other diseases that affect daily life. Various attempts have been made to develop wearable auxiliary devices using functional fabrics, but few have simultaneously provided both heat and pressure. Using knitted shape memory alloy (SMA) fabric, a module was manufactured that achieved bending and contraction during operation. An elbow brace that simultaneously provided heat and pressure was developed using this module. Subjective evaluation and measurements of the range of motion (ROM), changes in skin temperature (T sk), clothing pressure (P c), and blood flow (F b) were conducted on the elbow brace while being worn by 10 participants. The multifunctional elbow brace (MFEB) developed in this study generated pressure and heat that increased T sk and P c , ultimately increasing F b. In addition, the ROM of the elbow joint was increased after actuating the elbow brace. Subjective evaluation of the heat and pressure sensation demonstrated its applicability to the human body. We confirmed that the elbow brace had a positive effect on F b and increased the ROM of the joint. These results show the applicability of smart textiles to the development of various wearable devices.
Although stretching is recommended for fitness and health, there is little research on the effects of different stretching routines on hemodynamic responses of senior adults. It is not clear whether stretching can be considered an aerobic exercise stimulus or may be contraindicated for the elderly. The purpose of this study was to compare the effect of three stretching techniques; contract/relax proprioceptive neuromuscular facilitation (PNF), passive straight-leg raise (SLR), and static sit-and-reach (SR) on heart rate (HR) and blood pressure (BP) in senior athletes (119 participants: 65.6 ± 7.6 yrs.). Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP) and HR measurements were taken at baseline (after 5-minutes in a supine position), 45 and 90-seconds, during the stretch, and 2-minutes after stretching. Within each stretching group, (SLR, PNF, and SR) DBP, MAP and HR at pre-test and 2-min post-stretch were lower than at 45-s and 90-s during the stretch. SLR induced smaller increases in DBP and MAP than PNF and SR, whereas PNF elicited lower HR responses than SR. In conclusion, trained senior adult athletes experienced small to moderate magnitude increases of hemodynamic responses with SLR, SR and PNF stretching, which recovered to baseline values within 2-min after stretching. Furthermore, the passive SLR induced smaller increases in BP than PNF and SR, while PNF elicited lower HR responses than SR. These increases in hemodynamic responses (HR and BP) were not of a magnitude to be clinically significant, provide an aerobic exercise stimulus or warrant concerns for most senior athletes.
The purpose of this meta-analysis was to examine the effects of blood flow restriction training on resting blood pressure and heart rate. A meta-analysis was completed in May 2020 including all previously published papers on blood flow restriction and was analyzed using a random effects model. To be included, studies needed to implement a blood flow restriction protocol compared to the same exercise protocol without restriction. A total of four studies met the inclusion criteria for quantitative analysis including four effect sizes for resting systolic blood pressure, four effect sizes for resting diastolic blood pressure, and three effect sizes for resting heart rate. There was evidence of a difference [mean difference (95 CI)] in resting systolic blood pressure between training with and without blood flow restriction [4.2 (0.3, 8.0) mmHg, p = 0.031]. No significant differences were observed when comparing resting diastolic blood pressure [1.2 (−1, 3.5) mmHg p = 0.274] and resting heart rate [−0.2 (−4.7, 4.1) bpm, p = 0.902] between chronic exercise with and without blood flow restriction. These results indicate that training with blood flow restriction may elicit an increase in resting systolic blood pressure. However, lack of data addressing this topic makes any conclusion speculative. Based on the results of the present study along with the overall lack of long-term data, it is suggested that future research on this topic is warranted. Recommendations include making changes in resting blood pressure a primary outcome and increasing the sample size of the interventions.
PurposeTo investigate sports compression garment (CG)-induced recovery hemodynamics and their potential impact on subsequent cycling performance.Methods
In a randomized crossover design, 13 physically active men (20.9 ± 1.4 years; 65.9 ± 7.8 kg; 173.3 ± 4.8 cm; peak power output 254.2 ± 27.2 W) underwent 2 experimental trials. During each experimental trial, the subjects performed 20-min fatiguing preload cycling followed by 60-min passive recovery wearing either a sports CG (28.6 ± 9.4 mmHg) or gymnastic pants (CON). A 5-min all-out cycling performance test was subsequently conducted and power output and cadence were recorded. Cardiac output (CO) and stroke volume (SV) were measured using Doppler ultrasound (USCOM®). Heart rate (HR), blood lactate [BLa−], ratings of perceived exertion (RPE), leg muscle soreness (LMS), mean arterial pressure (MAP) and systemic vascular resistance (SVR) were monitored at 5, 15, 30, 45, 60 min during passive recovery.ResultsDuring the subsequent 5-min all-out cycling performance test, power output (215.2 ± 24.0 vs. 210.8 ± 21.5 W, CG vs. CON) and cadence (72.5 ± 3.8 vs. 71.2 ± 4.8 rpm, CG vs. CON) were higher in CG than CON (P < 0.05). SV was higher at 15, 30 and 45 min (P < 0.05), CO was higher at 5 and 45 min (P < 0.05), HR was lower at 15 and 30 min (P < 0.05) and [BLa−] was lower at 5 and 15 min (P < 0.05) during passive recovery, while LMS was lower at all time-points (P < 0.05) compared with CON.Conclusion
Sports CG improves subsequent cycling performance by enhancing hemodynamic responses and attenuating perceived muscle soreness during passive recovery in physically active men.
Flexible strain sensors and their sensing performance have been attractive in human motion detection applications. In this project, a knitted strain sensor was designed and fabricated via the technology of weft-knitting a nylon/nylon-wrapped spandex/silver-coated yarn into a knitted garment. Locations of sensor areas were customized to form a whole piece of knitted garment popular for today's applications in elastic tight-fitting activewear. The sensor provides electrical resistance data as a wearable sensing device for detecting body motions. A new method of using a three-dimensional curved surface to evaluate the sensing performance of the knitted strain sensor was proposed. Compared with the method of two-dimensional test, the three-dimensional test method was closer to the actual human sensing situation when the knitted sensor is worn. The strain sensing range of the three-dimensional curved surface was 120%, twice the sensing range of the two-dimensional surface. This research indicated that this three-dimensional surface testing method could be effectively applied in the sensing performance evaluation of fabric strain sensors.
Nowadays, compression garments (CGs) are widely used in winter racing sports, such as speed skating, short-track speed skating, alpine skiing, and cross-country skiing. However, the effect of wearing CGs on athletic performance in these specific sports is still not fully examined. Thus, the aim of this narrative review is to summarize the research and application of CGs in winter racing sports and to discuss how the CGs help athletes improve their performance in an integrative manner (i.e., physiology, aerodynamics, and biomechanics). A total of 18 experimental studies dedicated to CGs in winter racing sports were identified from the peer-review scientific literature. The main findings are as follows. (1) Currently, CG studies have mainly focused on drag reduction, metabolism, muscle function, strength performance, and fatigue recovery. (2) The results of most studies conducted in wind tunnels showed that, for cylindrical structures similar to the human body, clothing with rough surfaces can reduce air drag. Notably, the effect of CGs on drag reduction in real competition has not been fully explored in the literature. (3) Compression can reduce muscle vibrations at high impact and help athletes control the center of pressure movement, a function that is important for alpine skiing. Future studies are needed to improve current understanding of the effects of compression clothing microstructure on drag reduction and their stretching in different parts of the body. Furthermore, the design of experimental protocol must be consistent with those during the competition, thus providing a full discussion on energy metabolism, fatigue, and recovery affected by CGs.
This study aimed to investigate the differences in the interface pressure applied by sports and medical compression socks and assess the pressure gradient profile. Sixty (30 male, 30 female) national representative athletes were fitted with both medical grade and sports compression socks in a counterbalanced order. Interface pressure was assessed using a Kikuhime pressure monitor at three different landmarks on the lower leg to better understand absolute pressure application and pressure gradient profile. Medical grade compression socks exerted a small, yet significantly higher mean pressure across the three landmarks (28.8 ± 4.4 mmHg) than sports compression socks (26.3 ± 4.0 mmHg, p < 0.001, d = 0.57). Both garment types exhibited progressively graduated pressure profiles, where pressure was highest at the proximal end of the limb and lowest at the distal end. These findings highlight the possible differences between types of compression garments and their progressive, rather than graduated, pressure gradient.
Compression garments are elastic clothing with an engineered compression gradient that can be worn on limbs, upper, lower, or full body to use for therapy and sports. This article presents an overview and review on the compression garments and concentrates on the design of compression garments with an appropriate pressure for specific applications. It covers the types of compression garments, fibers and yarns, knitted fabric construction, garment design, an evaluation system, and pressure measurement and modeling. The material properties, fabric properties, pressure modeling, and the garment design system presents the prediction, design, and fabrication of the compression garments. Lastly, the research status and directions are discussed.
Background
Adequate recovery from exercise is essential to maintain performance throughout training and competition. While compression garments (CG) have been demonstrated to accelerate recovery, the literature is clouded by conflicting results and uncertainty over the optimal conditions of use. ObjectivesA meta-analysis was conducted to assess the effects of CG on the recovery of strength, power and endurance performance following an initial bout of resistance, running, or non-load-bearing endurance (metabolic) exercise. Methods
Change-score data were extracted from 23 peer-reviewed studies on healthy participants. Recovery was quantified by converting into standardized mean effect sizes (ES) [±95% confidence interval (CI)]. The effects of time (0–2, 2–8, 24, >24 h), pressure (<15 vs. ≥15 mmHg) and training status (trained vs. untrained) were also assessed. ResultsCG demonstrated small, very likely benefits [p < 0.001, ES = 0.38 (95% CI 0.25, 0.51)], which were not influenced by pressure (p = 0.06) or training status (p = 0.64). Strength recovery was subject to greater benefits than other outcomes [p < 0.001, ES = 0.62 (95% CI 0.39, 0.84)], displaying large, very likely benefits at 2–8 h [p < 0.001, ES = 1.14 (95% CI 0.72, 1.56)] and >24 h [p < 0.001, ES = 1.03 (95% CI 0.48, 1.57)]. Recovery from using CG was greatest following resistance exercise [p < 0.001, ES = 0.49 (95% CI 0.37, 0.61)], demonstrating the largest, very likely benefits at >24 h [p < 0.001, ES = 1.33 (95% CI 0.80, 1.85)]. Recovery from metabolic exercise (p = 0.01) was significant, although large, very likely benefits emerged only for cycling performance at 24 h post-exercise [p = 0.01, ES = 1.05 (95% CI 0.25, 1.85)]. Conclusion
The largest benefits resulting from CG were for strength recovery from 2 to 8 h and >24 h. Considering exercise modality, compression most effectively enhanced recovery from resistance exercise, particularly at time points >24 h. The use of CG would also be recommended to enhance next-day cycling performance. The benefits of CG in relation to applied pressures and participant training status are unclear and limited by the paucity of reported data.
Abstract The purpose of this investigation was to measure the interface pressure exerted by lower body sports compression garments, in order to assess the effect of garment type, size and posture in athletes. Twelve national-level boxers were fitted with sports compression garments (tights and leggings), each in three different sizes (undersized, recommended size and oversized). Interface pressure was assessed across six landmarks on the lower limb (ranging from medial malleolus to upper thigh) as athletes assumed sitting, standing and supine postures. Sports compression leggings exerted a significantly higher mean pressure than sports compression tights (P < 0.001). Oversized tights applied significantly less pressure than manufacturer-recommended size or undersized tights (P < 0.001), yet no significant differences were apparent between different-sized leggings. Standing posture resulted in significantly higher mean pressure application than a seated posture for both tights and leggings (P < 0.001 and P = 0.002, respectively). Pressure was different across landmarks, with analyses revealing a pressure profile that was neither strictly graduated nor progressive in nature. The pressure applied by sports compression garments is significantly affected by garment type, size and posture assumed by the wearer.
This study examined the effect of wearing different grades of graduated compression stockings (GCS) on physiological and perceptual measures during and following treadmill running in competitive runners. Nine males and one female performed three 40-min treadmill runs (80 +/- 5% maximal oxygen uptake) wearing either control (0 mmHg; CON), low (12-15 mmHg; LO-GCS), or high (23-32 mmHg; HI-GCS) grade GCS in a double-blind counterbalanced order. Oxygen uptake, heart rate and blood lactate were measured. Perceptual scales were used pre- and post-run to assess comfort, tightness and any pain associated with wearing GCS. Changes in muscle function, soreness and damage were determined pre-run, immediately after running and 24 and 48 h post-run by measuring creatine kinase and myoglobin, counter-movement jump height, perceived soreness diagrams, and pressure sensitivity. There were no significant differences between trials for oxygen uptake, heart rate or blood lactate during exercise. HI-GCS was perceived as tighter (P < 0.05) and more pain-inducing (P < 0.05) than the other interventions; CON and LO-GCS were rated more comfortable than HI-GCS (P < 0.05). Creatine kinase (P < 0.05), myoglobin (P < 0.05) and jump height (P < 0.05) were higher and pressure sensitivity was more pronounced (P < 0.05) immediately after running but not after 24 and 48 h. Only four participants reported muscle soreness during recovery from running and there were no differences in muscle function between trials. In conclusion, healthy runners wearing GCS did not experience any physiological benefits during or following treadmill running. However, athletes felt more comfortable wearing low-grade GCS whilst running.
The aim of this study was to examine the effect of wearing graduated compression stockings on physiological and perceptual variables during and after intermittent (Experiment 1) and continuous (Experiment 2) running exercise. Fourteen recreational runners performed two multi-stage intermittent shuttle running tests with 1 h recovery between tests (Experiment 1). A further 14 participants performed a fast-paced continuous 10-km road run (Experiment 2). Participants wore commercially available knee-length graduated compression stockings (pressure at ankle 18 - 22 mmHg) beneath ankle-length sports socks (experimental trials) or just the latter (control trials) in a randomized counterbalanced design (for both experiments). No performance or physiological differences were observed between conditions during intermittent shuttle running. During the 10-km trials, there was a reduction in delayed-onset muscle soreness 24 h after exercise when wearing graduated compression stockings (P < 0.05). There was a marked difference in the frequency and location of soreness: two participants in the stockings trial but 13 participants in the control trial indicated soreness in the lower legs. Wearing graduated compression stockings during a 10-km road run appears to reduce delayed-onset muscle soreness after exercise in recreationally active men.
The quantitative evaluation of clothing comfort is essential in the clothing industry. Garment constraint is caused by its tension along the curvature of the human body when in motion. Hence, the measurement of clothing pressure using test persons has been considered a representative tool for evaluating the motion adaptability of garments. Nevertheless, errors are caused by the individual differences among humans as well as the motion variance. In this study, a kinematic soft dummy model was designed and developed to measure clothing pressure. First, a model was selected that approximated the standard body proportions and dimensions of Japanese males in their 20s; the external mold was produced using gypsum. Second, a mechanical skeleton was inserted into the external mold, and the dummy was formed around the skeleton using a specific stiffness polyurethane simulating the modulus of human tissues. Third, the kinematic function was implemented through a control system that enabled the soft dummy to conduct “one leg raising”. Finally, the clothing pressure of the kinematic soft dummy was measured; it was fitted with menʼs suit pants that consisted of six worsted fabrics with different elongation ratios. Our results confirmed a particularly high correlation coefficient for the clothing pressure of the kinematic soft dummy and the test persons. They also confirmed a particularly high correlation coefficient for the clothing pressure of the kinematic soft dummy and the subjective evaluation by test persons. Therefore, the clothing pressure measurement with a kinematic soft dummy could be a novel and effective method for comfort evaluation.
Background
The benefits associated with sports compression garments are thought to be closely related to enhanced blood flow. However, findings are equivocal, possibly due to heterogeneity in techniques used for measuring blood flow, garment types used, and pressures applied. This study combined Doppler ultrasound and near-infrared spectroscopy technologies to provide the first comprehensive assessment of the effects of three sports compression garment types on markers of venous return and muscle blood flow at rest.
Methods
Resting lower-limb blood flow measures (markers of venous return, muscle blood flow, muscle oxygenation) of 22 elite, junior, male basketball players (age, 17.2 ± 0.9 years, mean ± SD) were assessed in 4 separate conditions: no compression (CON), compression tights (TIGHTS), compression shorts (SHORTS), and compression socks (SOCKS). Markers of venous return (cross-sectional area, time-averaged mean and peak blood flow velocity, and venous blood flow) were measured via Doppler ultrasound at the popliteal and common femoral veins. Muscle blood flow and muscle oxygenation were measured in the gastrocnemius medialis and vastus lateralis using near-infrared spectroscopy.
Results
Popliteal markers of venous return were higher in TIGHTS compared to CON (p < 0.01) and SHORTS (p < 0.01), with SOCKS values higher compared with CON (p < 0.05). Common femoral vein markers of venous return were higher for all conditions compared to CON (p < 0.05), with TIGHTS values also higher compared to SOCKS (p < 0.05). Gastrocnemius medialis blood flow was higher for TIGHTS compared to CON (p = 0.000), SOCKS (p = 0.012) and SHORTS (p = 0.000), with SOCKS higher compared to SHORTS (p = 0.046). Vastus lateralis blood flow was higher for TIGHTS compared to CON (p = 0.028) and SOCKS (p = 0.019), with SHORTS also higher compared to CON (p = 0.012) and SOCKS (p = 0.005). Gastrocnemius medialis oxygenation was higher for TIGHTS compared to CON (p = 0.003), SOCKS (p = 0.033) and SHORTS (p = 0.003), with SOCKS higher compared to CON (p = 0.044) and SHORTS (p = 0.032). Vastus lateralis oxygenation was higher for TIGHTS compared to CON (p = 0.02) and SOCKS (p = 0.006).
Conclusion
Markers of venous return, muscle blood flow, and muscle oxygenation are increased with sports compression garments. TIGHTS were most effective, potentially due to the larger body area compressed.
Flexible pressure sensors are being used widely in sports and human-health monitoring. The knee joint is one of the organs with the highest injury rate while running. By optimizing the structural design of sports pants, the lower limbs can be compressed appropriately to protect the knee joint and improve exercise efficiency. The point of innovation lies in the removable flexible pressure sensors implanted in these leggings developed to monitor the three-dimensional force on the knee in real time. Combined with data analysis, this can provide information to wearers while exercising and to the middle-aged and elderly to prevent knee-strain problems. The experimental results showed that the pressure values of the left and right knee joints measured using the flexible pressure sensors on the leggings in real time and those obtained using the AMI3037-5s Airbag pressure tester were accompanied by F-values and t-test statistical probability values greater than 0.05. This indicates that there was no significant difference between the two values, reflecting the credibility of the flexible pressure-monitoring data. The oxygen saturation and total hemoglobin content of a subjects’ legs after exercising were higher than those before exercising, indicating that the leggings performed well in terms of fatigue relief. The subjects’ body surface temperature, when exercising, changed steadily and dropped gradually in the later stage, indicating that the leggings perform well with respect to thermal and moisture comfort. Flexible sensing technology has promising application prospects in wearable smart clothing in future, particularly in the sports and health fields.
The stretch property of fabrics is one of the most important factors that provide comfort to wearers. It is expected that tension building up in the fabric can be relaxed and the garment pressure on the body can be reduced by appropriately exploiting its stretch property. Currently, the stretch property is predominantly realized using spandex. However, weaving or knitting elastic threads cannot be employed for the worsted fabric used to design men’s suits because of their effects on the mechanical properties of the fabric (e.g., embrittlement), which deteriorate with time. In this study, worsted fabric with a graded mechanical stretch property was produced, and the effect of the mechanical stretch property on comfort was verified. The mechanical stretch property is developed from the tension relaxation and fabric shrinkage along the weft yarn during the crabbing, scouring, and drying stages of the finishing process. Then, the form of the fabric is set by heating. In this study, the worsted fabric had an elongation ratio varying from 5.9% to 16.1% along the weft direction that was produced without using elastic thread. Furthermore, men’s suit pants were made from the fabrics. The effect of the stretch property on the garment comfort was verified through sensory evaluation and garment pressure measurement. The contribution of the mechanical stretch property in improving the garment comfort of men’s suit pants is discussed.
Clothing pressure is one of the most important factors in clothing design as it is closely related to the wearing comfort of a garment. Although a few examples of estimating clothing pressure via simulation have been reported so far, the calculations are often difficult since clothing simulation is a non-linear analysis. Therefore, this study proposes a convenient method for estimating clothing pressure by combining a generic apparel computer aided design (CAD) program and finite element analysis software. In the first step, the three-dimensional (3D) shape of the clothing is acquired from its pattern using an apparel CAD program. Then, with the 3D shape of the clothing as the initial shape, a finite element analysis is conducted to calculate the contact between the human body and the clothing using the stress and strain arising in the cloth when it is worn as the loading conditions. Finally, the clothing pressure is computed as the pressure at the contact surface between the clothing and the human body. To validate the proposed method, the clothing pressures of two types of underwear-type compression wear were measured while draped on a torso. When compared to the actual measured values, the average error of the proposed method was 0.24 kPa and the correlation was r = 0.83. These results confirm that the proposed method can estimate clothing pressure with a reasonable degree of accuracy.
The inward displacement perpendicular to body surface produced by external pressure is an important index to evaluate pressure comfort and optimal design of tight clothing products. Because of the limited pressure exerted on the human body after wearing compression clothing, the corresponding displacement is generally small, and it is difficult to obtain an accurate displacement value of the human body using general methods. In this paper, we focused on the functional relationship between pressure and displacement when the human body was in the walking state after dressing in elastic pantyhose, and then the displacement data could be easily obtained using this method.
Through computerized tomography scanning, establishing of the waist cross-section, finite element simulation, and curve fitting, we finally obtained the functional relationship between the pressure/displacement ratio and angle when the body is dressed in four sample elastic pantyhose during the walking process in this study. In the formula, pressure data can be easily obtained through the pressure experiment, and the corresponding displacement value at any point of the human body can be calculated using the quadratic fitting curve equation. Results indicated that no matter what state the human body was in (static or dynamic) after wearing elastic pantyhose, the relationship between pressure and displacement at the corresponding point remains basically unchanged. That is to say, the relationship between pressure and displacement was basically not affected by the state of the human body when dressed in a tight garment. The conclusions provide an important reference for evaluating pressure comfort and optimizing clothing structure. This method is also applicable to other types of compression clothing.
Purpose
Graduated compression shaping pants (GCSPs) are shapewears sharing the same action mechanisms as medical compression stockings (MCSs), setting four stages of pressure on lower limbs that gradually decreasing from the ankle to the thigh root. They are claimed to be able to not only shaping bodies but also promoting blood circulation in legs. However, there are few studies on whether GCSPs perform the advertised functions and how effective GCSPs could be. The purpose of this paper is to explore and evaluate the pressure distribution and body-shaping effectivity of GCSPs.
Design/methodology/approach
The authors first select two graduated compression shaping pants (GCSPs-A, GCSPs-B) and a pair of professional shaping pants as the Controls. Then objective pressure test and 3D body scanning test are conducted. Finally, the pressure distribution and body-shaping effectivity are demonstrated by ORIGIN and MATLAB, compared with controls.
Findings
GCSPs-A perform significant body-shaping effectivity at the calf, thigh and thigh root, which are less effective than the Controls. The body-shaping effectivity of GCSPs-B is predicted weaker than GCSPs-A at the calf and thigh, while better at the thigh root. Both GCSPs-A and GCSPs-B show gradual pressure, which could be classified into Class I or II of MCSs. Comprehensively, GCSPs-A are superior than GCSPs-B.
Originality/value
In this paper, authors evaluate the pressure distribution and body-shaping effectivity of GCSPs, which could provide guidance for enterprises to further optimize and produce GCSPs, performing better functions that meet consumers' needs better.
Compression garments due to their numerous medical applications have been recently attracted to be mechanically analyzed for their compression mechanism. Predicting the pressures applied to musculoskeletal tissues supported by these garments is a good solution for doing such analyzing which could be simply achieved by the help of finite element method. In this paper, the main aim was investigating the structural effect of knitted compression garments used for supporting the body lower-limb musculoskeletal system. Compression garments of weft knitted rib structure containing elastane yarn were prepared according to the leg’s dimensions of a healthy 27-year old person. Using Kikuhime measuring device, experimental values of the applied pressure were measured in order to be compared with theoretical results. For developing a three-dimensional biomechanical model for the leg system supported by compression garment, images form computed tomography scanning methodology was used. Tensile properties of an elastane yarn as the basis for studying the compression garment’s mechanical behavior were experimentally measured and then simulated in Abaqus software as a linear viscoelastic material. The results were then applied to multi-scale modeling technique in order to simulate mechanical behavior of the knitted fabric and the compression garment thereof. Combination of both experimental and theoretical results was applied to simulate interactions between the leg and the compression garment. The results indicated that the pressure values simulated by finite element method were predicted with the maximum mean error of 19.64 % and total error mean of 12.29 % compared to experimental results. Small difference between the measured and simulated values was observed for tibia and fibula because of their low soft-tissue volume. The proposed model enables the specialists to present compression garments based on the patient’s needs and physician prescription which generate the optimal treatment.
Purpose:
This study investigated the relationship between blood flow restriction (BFR) cuff pressure and blood flow at rest and during exercise, with the aim of determining if lower cuff pressures will provide an ischemic stimulus comparable to higher pressures.
Methods:
The relationship between blood flow and cuff pressure at rest was determined by measuring blood flow (Doppler Ultrasound) through the superficial femoral artery (SFA) in 23 adults across a range of pressures (0-100% Arterial Occlusion Pressure at rest, rAOP). The interplay between cuff pressure, blood flow and exercise was assessed by determining AOP at rest and during plantar flexion exercise (eAOP) and subsequently measuring the blood flow response to plantar flexion exercise with BFR cuff pressure set to either 40% rAOP or 40% eAOP.
Results:
At rest, a non-linear relationship between cuff pressure and blood flow through the SFA exhibited a plateau at moderate pressures, with non-significant differences in blood flow (~9%, P = 1.0) appearing between pressures ranging from 40-80% rAOP. While eAOP was greater than rAOP (229±1.5 vs. 202±1.5 mmHg, P<0.01), blood flow during plantar flexion exercise did not significantly differ (P=0.49) when applying 40% rAOP or 40% eAOP.
Conclusion:
Blood flow through the SFA exhibits a non-linear relationship with cuff pressure, such that cuff pressures in the range of 40-80% rAOP reduce blood flow to approximately the same degree. BFR interventions opting for lower (e.g. 40% AOP), more comfortable pressures will likely provide an ischemic stimulus comparable to that of higher (80% AOP), less-comfortable pressures.
This paper presents a new design and development process for integrating illuminated Polymeric Optical Fibre (POF) into knitted garments, by incorporating POF directly into the looped structure. Fully-fashioned knitting is presented as a means of overcoming garment design restrictions in existing works. A key challenge this work addresses is the creation of more appealing and fashionable form-fitting illuminated POF garments. The resultant work, a tight-fitting knitted raglan sleeve jumper with a section of knitted POF demonstrates that new aesthetics can be achieved, with our new technique. This project builds on existing research into POF integration into fashion and textiles, whilst challenging the existing view that POF cannot be formed into a looped structure. This project used a hand flat knitting machine to produce the knitted POF garment, to balance the benefits of using handcraft techniques for challenging fibres, with the faster knitting speed better associated with using knitting machines.
Purpose
The purpose of this paper is to analyze the effects of wearing compression pants of varying pressure levels on the wearer’s attention/concentration to investigate the appropriate level of compression for sport performance and confirm whether this methodology is feasible as a means of evaluating sportswear functionality.
Design/methodology/approach
After wearing compression pants of varying compression levels, spontaneous potentials were analyzed by calculating the spontaneous electroencephalography (EEG) indices: relative low beta (RLB) power spectrum ((12~15 Hz)/(4~50 Hz)), relative mid beta (RMB) power spectrum ((15~20 Hz)/(4~50 Hz)), and ratio of sensory motor rhythm to theta waves ((12~15 Hz)/(4~8 Hz)). The activation of brain waves was mapped and visualized from EEG data using BioScan-Map (BioBrain Inc., Daejeon, Korea).
Findings
The influence of pressure levels on brain waves was confirmed: RLB power, RMB power and RST varied by experimental clothing. CP3, the compression pants that applied moderate pressure (1.57±0.41 kPa), was associated with a relatively higher level of attention/concentration – i.e., the results confirmed that sports compression pants that apply approximately 1.0~2.0 kPa to the area between the thighs and shins are improve attention/concentration. It was further confirmed that EEG is a useful tool for evaluating the psychophysiological effects of functional apparel.
Originality/value
Unlike preceding studies that considered only alpha waves and the effects of clothing on comfort, this study investigated the influence of compression garments on attention/concentration.
This research has been conducted to develop mathematical models to predict the compression pressure and strain value of fabric based on Laplace's law. The experiment was designed in accordance with the strain values of stretched fabric in order to make prediction of compression pressure. The fabrics covered on rigid cylindrical models and thigh part of human body were compared and measured for pressure values using compression tester. The results revealed that pressure values on rigid body were overestimated which may result from the cause of sensor thickness. Later, correction factor was included in calculations in order to get rid of the overestimated pressure. It was also found that predicted pressures were close to the ones being measured on rigid body by compression tester after multiplying with the correction factor, while soft tissue surface had no influential effect on pressure perturbation and pressure-measured values were close to the predicted pressure values obtained from modelling.
The interdisciplinary approach for the design of compression garments was developed by means of establishing new databases about the elongation of knitted materials, the morphology of female bodies, and the relations between both with the pressure under the garment. We used KES-FB1 and a cylinder made of cosmetology silicone to investigate the relationship between the knitted material strain and the pressure produced.
To find the factors that are responsible for comfort perception of compression garments, a sensory analysis with female participants was used to establish the pressure range that is permissible for the human body and the effect of its reshaping.
The experimental data obtained was used for validating the theoretical approaches about, firstly, the transformation of a solid polygonal avatar of the scanned body to the soft one, secondly, the virtual three-dimensional (3D) creation of a compression garment in a “relaxed non-elongation state” and, thirdly, obtaining virtual two-dimensional (2D) pattern blocks. Science explorations dedicated to 3D-to-2D flattening of pattern blocks of the avatar surface and to the creation of tight-fitted garments were considered as the background of our research.
Several compression garments for females with different morphological features, which were designing by means of a new 3D-to-2D method for flattening of pattern blocks and the traditional 2D “Müller and Sohn” manual, were obtained. The mean value of absolute difference between the predicted and measured pressure was improved from 33% to 14%. Thus, the developed approach based on contemporary virtual reality collection of input data allows one to predict the pressure of compression garments with higher accuracy.
This study aimed to describe the effect of compression garments on middle cerebral artery blood flow velocity (MCAv) in relation to cognitive and exercise performance whilst cycling. In a randomised-controlled-cross-over design, 15 well-trained male cyclists were recruited to participate in three identical trials wearing loose fitting shorts (control), low-grade, or medium-grade compression garments. The protocol involved four 8 min increments of cycling at 30%, 50%, 70%, and 85% maximal power output and a 4 km time-trial. Participants undertook a cognitive Stroop task at baseline and at the midpoint of each increment. MCAv was monitored with Transcranial Doppler Ultrasonography. Mean arterial pressure (MAP) and partial pressure of end-tidal CO2 (PetCO2) were measured throughout. MCAv, MAP, PetCO2, and reaction time of the complex Stroop task were influenced by exercise intensity, but not compression garments. Compression garments significantly affected cognitive accuracy in the complex Stroop task such that low-grade compression appeared to enhance cognitive accuracy in comparison to the control condition at the highest intensity (p = .010). Time-trial performance did not differ between the control (338.0 ± 17.3 s), low-grade (338.7 ± 18.7 s), or medium-grade (342.2 ± 19.3 s) conditions (p = .114). Compression garments did not affect MCAv during exercise or time-trial performance, but compression may be beneficial for improved cognitive accuracy during high-intensity exercise. Further research is required to elucidate the potential impact on cognitive performance.