How does Under Armour’s ColdGear Compression Mock enhance athletic performance. What makes this garment ideal for cold weather workouts. Why is compression technology beneficial for athletes.
The Revolutionary ColdGear Compression Mock: A Game-Changer for Athletes
Under Armour has long been at the forefront of innovative athletic apparel, and their ColdGear Compression Mock is no exception. This cutting-edge garment combines advanced fabric technology with ergonomic design to provide athletes with unparalleled performance and comfort during cold weather training sessions.
The ColdGear Compression Mock is available in a range of sizes from X-Small to 4X-Large, including Tall options, ensuring a perfect fit for athletes of all body types. With a price range of $34.80 to $53.95, it offers excellent value for its high-quality construction and performance-enhancing features.
Key Features of the ColdGear Compression Mock
- Dual-layer fabric for optimal insulation and moisture management
- Compression fit to improve muscle support and circulation
- Mock neck design for added warmth and protection
- Four-way stretch material for unrestricted movement
- Anti-odor technology to keep you fresh during intense workouts
The Science Behind ColdGear Technology: How It Keeps You Warm and Dry
ColdGear technology is the cornerstone of Under Armour’s cold weather performance wear. But how exactly does it work? The secret lies in its innovative dual-layer fabric construction.
The inner layer is soft and brushed, providing a comfortable feel against the skin while efficiently wicking away sweat. The outer layer is smooth and fast-drying, allowing moisture to evaporate quickly while trapping heat to keep you warm. This combination creates a microclimate around your body, regulating temperature and humidity for optimal performance in cold conditions.
Benefits of ColdGear Technology
- Efficient moisture management
- Superior heat retention
- Lightweight and breathable
- Quick-drying properties
- Comfortable next-to-skin feel
Compression Technology: Enhancing Athletic Performance and Recovery
The compression fit of the Under Armour ColdGear Mock is more than just a snug feel – it’s a performance-enhancing feature backed by scientific research. Compression garments have been shown to provide numerous benefits for athletes during both exercise and recovery periods.
How does compression technology improve athletic performance?
Compression garments apply pressure to specific muscle groups, which can lead to increased blood flow and oxygen delivery to working muscles. This enhanced circulation can result in improved endurance, reduced muscle fatigue, and decreased recovery time between intense bouts of exercise.
Recovery Benefits of Compression Wear
- Reduced muscle soreness and inflammation
- Faster clearance of metabolic waste products
- Improved lymphatic drainage
- Enhanced proprioception and body awareness
Versatility in Action: From Training to Competition
The Under Armour ColdGear Compression Mock is designed to excel in a variety of athletic contexts. Its versatile design makes it suitable for everything from high-intensity interval training to endurance sports and team competitions.
Ideal Activities for the ColdGear Compression Mock
- Winter running and trail running
- Cold weather cycling
- Outdoor team sports (football, soccer, rugby)
- Skiing and snowboarding base layer
- High-altitude training
The mock neck design provides additional protection against the elements, making it an excellent choice for athletes who train or compete in challenging weather conditions. The compression fit also helps to reduce wind resistance, which can be particularly beneficial for cyclists and runners.
Sizing and Fit: Ensuring Optimal Performance
Proper sizing is crucial for compression garments to deliver their full range of benefits. Under Armour provides a comprehensive size chart to help athletes select the right fit for their body type.
Understanding Under Armour’s Size Chart
The size chart for the ColdGear Compression Mock includes measurements for chest and waist circumference. For example, a Medium size is recommended for individuals with a chest measurement of 37-41 inches and a waist measurement of 31-34 inches.
It’s important to note that compression wear should fit snugly without being restrictive. If you’re between sizes, it’s generally recommended to size up for comfort while still maintaining the benefits of compression.
Tips for Achieving the Perfect Fit
- Take accurate body measurements before ordering
- Consider your intended use (training vs. competition)
- Account for personal preferences in compression level
- Remember that compression garments may feel tighter initially but will adapt to your body over time
Care and Maintenance: Prolonging the Life of Your ColdGear Compression Mock
To ensure your Under Armour ColdGear Compression Mock maintains its performance properties and longevity, proper care is essential. Following the manufacturer’s care instructions will help preserve the garment’s compression, moisture-wicking abilities, and overall durability.
General Care Guidelines
- Machine wash cold with like colors
- Use gentle, non-bleach detergents
- Avoid fabric softeners, which can clog moisture-wicking fibers
- Tumble dry on low heat or air dry
- Do not iron or dry clean
By following these care instructions, you can help ensure that your ColdGear Compression Mock continues to perform at its best, workout after workout.
Customer Reviews and Satisfaction: Real-World Performance
With over 12,500 ratings and an impressive 4.7 out of 5 stars, the Under Armour ColdGear Compression Mock has garnered widespread praise from athletes and fitness enthusiasts alike. These real-world experiences provide valuable insights into the garment’s performance and durability.
What do customers love about the ColdGear Compression Mock?
- Exceptional warmth without bulkiness
- Superior moisture management during intense workouts
- Comfortable fit and range of motion
- Durability and long-lasting performance
- Versatility for various sports and activities
Many users report that the ColdGear Compression Mock has become an essential part of their cold weather training gear, praising its ability to keep them warm and dry even in challenging conditions.
Comparing the ColdGear Compression Mock to Other Cold Weather Performance Wear
While the Under Armour ColdGear Compression Mock stands out as a top performer in the cold weather athletic wear market, it’s worth considering how it compares to similar products from other brands.
Key Factors to Consider When Comparing Cold Weather Performance Wear
- Insulation effectiveness
- Moisture management capabilities
- Compression level and muscle support
- Durability and longevity
- Price point and value for money
When evaluated across these criteria, the ColdGear Compression Mock consistently ranks among the top choices for athletes seeking high-performance cold weather gear. Its combination of advanced fabric technology, ergonomic design, and competitive pricing make it a standout option in a crowded market.
Potential Alternatives to Consider
- Nike Pro Warm Mock Neck Top
- Adidas Techfit Cold Weather Mock
- 2XU Thermal Compression Top
- SKINS DNAmic Thermal Mock Neck
While these alternatives offer their own unique features and benefits, the Under Armour ColdGear Compression Mock remains a top contender due to its proven performance and positive user feedback.
Incorporating the ColdGear Compression Mock into Your Training Regimen
To maximize the benefits of the Under Armour ColdGear Compression Mock, it’s important to understand how to effectively integrate it into your training routine. This versatile garment can be used as a standalone piece or as part of a layering system for extreme cold conditions.
Strategies for Optimal Use
- Wear as a base layer under loose-fitting outerwear for added insulation
- Use as a standalone top for high-intensity workouts in cool conditions
- Pair with ColdGear leggings for full-body compression and warmth
- Incorporate into your pre-workout warm-up routine to enhance muscle activation
- Wear post-workout to aid in recovery and reduce muscle soreness
By strategically using the ColdGear Compression Mock throughout your training cycle, you can enhance your performance, comfort, and recovery in cold weather conditions.
Adapting to Different Weather Conditions
The ColdGear Compression Mock is designed to perform across a range of cold weather conditions, but it’s important to adjust your usage based on temperature and activity level. In milder conditions or during high-intensity workouts, you may find that the mock provides sufficient warmth on its own. For extreme cold or lower-intensity activities, layering with additional insulation may be necessary.
The Future of Cold Weather Performance Wear: Innovations on the Horizon
As technology continues to advance, the future of cold weather performance wear looks increasingly promising. Brands like Under Armour are at the forefront of developing new materials and technologies to enhance athletic performance in challenging conditions.
Emerging Trends in Athletic Apparel Technology
- Smart fabrics with integrated heating elements
- Adaptive compression that adjusts based on muscle activity
- Biometric sensors for real-time performance tracking
- Advanced thermoregulation using phase-change materials
- Sustainable and eco-friendly fabric innovations
While the current ColdGear Compression Mock already offers exceptional performance, these emerging technologies hint at even more advanced cold weather gear in the future. As these innovations become more accessible, athletes can look forward to even greater comfort, performance, and adaptability in their cold weather training apparel.
The Role of Sustainability in Future Performance Wear
As environmental concerns become increasingly important to consumers, athletic apparel brands are focusing on developing sustainable materials and production processes. Future iterations of cold weather performance wear may incorporate recycled materials, bio-based fabrics, and more environmentally friendly manufacturing techniques without sacrificing performance or durability.
The Under Armour ColdGear Compression Mock represents the current pinnacle of cold weather performance wear, combining advanced fabric technology, ergonomic design, and proven benefits for athletes. As the field continues to evolve, this garment serves as a benchmark for innovation in athletic apparel, promising even greater advancements in the years to come.
Amazon.com: Under Armour Men’s ColdGear Compression Mock : Clothing, Shoes & Jewelry
| Price: | $34.80$34.80 – $53.95$53.95 |
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Color:
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Size:
Select X-Small Small Medium Medium Tall Large Large Tall X-Large XX-Large XX-Large Tall 3X-Large 3X-Large Tall 4X-Large 4X-Large Tall Select
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Size Chart
US Shirt
| Brand Size | US Size | Chest (in) | Waist (in) |
|---|---|---|---|
| XS | XS | 31 – 34 | 28 – 29 |
| S | S | 34 – 37 | 29 – 31 |
| M | M | 37 – 41 | 31 – 34 |
| L | L | 41 – 44 | 34 – 37 |
| XL | XL | 44 – 48 | 37 – 41 |
| XXL | XXL | 48 – 52 | 41 – 45. 5 |
| 3XL | 3XL | 52 – 56 | 45.5 – 50 |
| 4XL | 4XL | 56 – 60 | 50 – 54.5 |
| 5XL | 5XL | 60 – 64 | 54.5 – 59 |
Amazon.com: Under Armour Men’s ColdGear Armour Compression Mock Long-Sleeve T-Shirt : Clothing, Shoes & Jewelry
4.7 4.7 out of 5 stars
12,524 ratings
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| Price: | $42.50$42.50 – $120.13$120.13 |
Fit:
True to size. Order usual size.
Color:
Black (001)/Steel
Size:
Select X-Small Small Medium Large Large Tall X-Large X-Large Tall XX-Large XX-Large Tall 3X-Large 3X-Large Tall 4X-Large 4X-Large Tall Select
Update Page
Size Chart
US Shirt
| Brand Size | US Size | Chest (in) | Waist (in) |
|---|---|---|---|
| XS | XS | 31 – 34 | 28 – 29 |
| S | S | 34 – 37 | 29 – 31 |
| M | M | 37 – 41 | 31 – 34 |
| L | L | 41 – 44 | 34 – 37 |
| XL | XL | 44 – 48 | 37 – 41 |
| XXL | XXL | 48 – 52 | 41 – 45. 5 |
| 3XL | 3XL | 52 – 56 | 45.5 – 50 |
| 4XL | 4XL | 56 – 60 | 50 – 54.5 |
| 5XL | 5XL | 60 – 64 | 54.5 – 59 |
Roxtec Wedge Compression Block and Roxtec Wedgekit
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Roxtec Transit Designer™
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Roxtec Transit Designer™ is your shortcut to safety and efficiency.
This free web application simplifies product selection as well as the entire cable and pipe gland design process.
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The Roxtec Wedge compression block is used in frames with rectangular sealing zones to seal cables, pipes, modules and spacer plates. The Roxtec Wedgekit contains all the necessary components to compress a system.
- Used with appropriate Roxtec components as part of a complete sealing system
WEDGE 120 GALV
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| Header | Dimensions, W (mm) | Weight (kg) | Ref. No. | |
|---|---|---|---|---|
| WEDGEKIT 60 AISI316 | 60 | 0.8 | AWK0006001011 | |
| WEDGEKIT AISI316 | 120 | 1.5 | AWK0001201021 | |
| WEDGE 60 AISI316 | 60 | 0. 4 | ARW0000601021 | |
| WEDGE 120 AISI316 | 120 | 0.8 | ARW0001201021 |
| Header | Dimensions, W (mm) | Weight (kg) | Ref. No. | |
|---|---|---|---|---|
| WEDGEKIT 60 GALV | 60 | 0. 8 | 5AWK000000283 | |
| WEDGEKIT GALV | 120 | 1.5 | AWK0001201018 | |
| WEDGE 60 GALV | 60 | 0.4 | ARW0000601018 | |
| WEDGE 120 GALV | 120 | 0. 8 | ARW0001201018 |
comparison of in vivo and in vitro measurements
Clinical studies have shown that the effect of compression therapy in chronic venous insufficiency depends mainly on two factors [1-4]:
1) compression pressure of the product on the limb;
2) elastic properties (stiffness) of the material, which determine the action of knitwear in standing and walking positions.
With each muscle systole, the circumference of the tibia increases, which leads to an increase in back pressure from the compression bandage. This effect is more pronounced, the lower the elasticity of the fabric of the product.
These parameters, which determine the “dosage” of compression therapy, are of great interest to clinicians and should be declared in future studies. The physician prescribing compression products rarely realizes that the pressure ranges indicated on the packaging are obtained in laboratory conditions and not in tests in vivo .
Typically, the pressure exerted by the knitwear is calculated from the force/tension diagrams of the elastic product, which are obtained on the model of the limb of a certain cross section using the Laplace formula. The pressure range specified by the manufacturer is determined by the force that must be applied to the elastic product at a certain level in order to stretch it in the transverse direction. The ratio of the amount of tension to the force spent on this tension at different levels of the product forms the degree of slope of the so-called “force/tension curve”, which reflects the elasticity of the material [5].
Recently, measuring devices have been introduced to determine the pressure and stiffness of compression products in vivo [6]. The aim of this study was to compare the pressure and stiffness of several medical compression garments measured directly on the extremity with the same parameters determined using methods used by knitwear manufacturers.
Material and methods
Subject parameters.
The pressure exerted by several compression garments was measured on 12 lower extremities of 6 employees of Salzmann Medico (St. Gallen, Switzerland) after obtaining their informed consent to participate in the study. The average age of the participants in the experiment was 43.2 years (range 20-61 years). The studied limbs are divided into clinical classes in accordance with the CEAP classification as follows: C0 (6 limbs), C1 (4) and C2 (2). In table. 1 summarizes some basic information about volunteers. None of them used compression stockings in everyday life. The study was carried out in the laboratory of Salzmann Medico in Switzerland.
Measurements in vivo . A medical knitwear tester (TMT) manufactured by Salzmann Medico was used. It is a flat, air-filled sleeve with a large surface area and minimal volume, with 4 electrical contacts that allow pressure measurements at 4 levels [7].
Measurements were taken at the following points along the inner surface of the lower leg [8, 9]:
B – region of the ankle joint posterior to the medial malleolus;
B1 – 8 cm higher, at the junction of the Achilles tendon to the gastrocnemius muscle;
C – 19 cm above the ankle joint in the middle part of the leg;
D – 30 cm above the ankle joint.
In fig. 1Figure 1. Measurement of compression pressure using TMT. Measurement points: B (ankle level), B1 (gaiter level), C (level of the largest circumference of the lower leg), D (level below the knee joint). the TMT is shown mounted on a wooden leg model and the measurement points are marked. Compression stockings (Salzmann Medico) fitted at the ankle and below the knee were tested for TMT in the following configurations: one Venosan 1st compression stocking; two golf Venosan 1st compression class; one golf Venosan 2nd compression class; one golf Venosan 3rd compression class. The pressure range at the level of point B, declared by the manufacturer for the 1st class as 15-21 mm Hg, for the 2nd class as 23-32 mm Hg. and for the 3rd class as 34-46 mm Hg, complied with European standards [8, 9]. These standards regulate the pressure profile along the limb: at point B1, the pressure should be 70-100%, at points C and D – 50-80% of the initial pressure at the ankle level. In vivo pressure measurements of were taken with the volunteer lying down and standing.
The B1 level measurement point on TMT was taken as a reference point and marked on the leg and on the stocking. As an important parameter characterizing the elastic properties of the tested products, the static stiffness index (SSI) was calculated, which is the difference in resting pressure at point B1 in the position of the test subject lying on his back and in the standing position [10].
in vitro measurements . The same socks that were tested on the legs of volunteers were put on wooden lower limb models with TMT to measure pressure at different levels (see Fig. 1).
In accordance with the parameters obtained from the measurement of the lower limbs of volunteers, models of three sizes were used: small, medium and large (see table. 1). Then, transverse segments 5 cm wide were cut from the knitwear at the level of point B1. These ring segments were installed in a Zwick dynamometer, and after 5 repeated cycles of overstretch, force/stretch curves were calculated [9].
On the 6th cycle, the stockings were stretched to half the circumference at point B1, which was 13.5 cm for small, 15 cm for medium and 17 cm for large. The resulting force/stretch curve is the ratio of the tensile force in newtons (N) to the elongation (stretch) in centimeters. The pressure is determined by the ratio of the tensile force to the surface area. The unit of pressure is pascal (Pa), 1 Pa is equal to the ratio 1H/1 m 2 . In medicine, pressure is usually measured in millimeters of mercury (mm Hg), while 1 N / cm 2 equals 75 mm Hg. The local pressure P1 for the B1 segment is calculated by dividing the force by the surface area of a cylinder 1 cm high and a circumference equal to the circumference of the limb at the level of B1. Based on the resulting curve, you can calculate the force required to stretch the product one additional centimeter. It can be used to calculate the local pressure of segment B1 when the circumference increases by 1 cm (P2).
The difference P2-P1 corresponds to the rigidity of the product, which is the change in pressure when the segment is stretched with an increase in its circumference by 1 cm [8].
Statistical analysis. The results of the study are presented as means and standard deviations. Compression products were compared using the non-parametric Friedman test and Dunn’s test for multiple analysis. To compare different measurement methods, the nonparametric Spearman rank correlation coefficient and the Bland-Altman method [11] were used.
Results
Pressure measured with TMT. In tab. Figure 2 shows the pressure values exerted by the studied knitwear at all measurement points in the standing and lying position both on the volunteers’ legs and on limb mock-ups.
Pressure differences between compression classes were found to be statistically significant at the B1 level, which was the baseline in our dyno comparisons. The pressure of various models in position B1 was within the pressure range declared by the manufacturer for each compression class.
Mean pressure measured at the ankle (point B) on the lower limb was often lower than the pressure at point B1, while on the wooden mock-up the higher values were always measured at the ankle. Thus, a direct comparison of our data on the B1 level obtained by in vivo , with pressure values in vitro declared by the manufacturer, is not possible. This is due to the fact that international standards rely on measurements at ankle level B, which is poorly suited for in vivo measurements of [6].
It is interesting to note that the highest pressure was obtained when using two stockings of the 1st class, dressed one on top of the other, which turned out to be even higher than the pressure of the stockings of the 3rd compression class.
Comparison of pressure values obtained on TMT ( in vivo ) and using dynamometry ( in vitro ). When comparing products worn in one layer, the pressure values of golf of different compression classes, measured using TMT at level B1, were similar to the values calculated on the basis of force/tensile curves obtained by dynamometry of circular knitwear segments cut at level B1 (Fig.
2).Figure 2. Compression pressure measurement comparison in vivo and in vitro . Left: The pressure of several compression garments measured with the TMT at point B1 (gaiter level). Right: Pressure calculated from force/stretch curves obtained from dynamometry of some compression garments. Bland-Altman plot (Fig. 3), Figure 3. Bland-Altman plot for comparing TMT and dyno measurements. Comparison of compression pressure values measured with TMT at point B1 (sock level) with calculated values obtained using force/extensibility curves based on dynamometry in vitro . On the abscissa – the degree of coincidence of measurements; along the y-axis – differences in the measurement results. plotted on the basis of the pressure values of the golf, worn in one layer, shows that the measurement values of in vivo and in vitro are very close. The displacement (deviation from the mean value) was 2.13 and 4.1 mmHg. In 95% of subjects, the deviation was in the range from -0.
1 to 5.8 mmHg. The correlation was statistically significant (Fig. 4; Fig. 4. Correlation between the compressive pressure values of class 1-3 knitwear, measured using TMT in vivo and Zwick dynamometer in vitro . CI – confidence interval. R
Hardness. Rigidity is defined as an increase in compression pressure per 1 cm increase in limb circumference [8]. The static stiffness index (SSI) was defined as the pressure difference between an active standing position and a relaxed lying position [6, 10]. SSI measured with TMT on 12 knee socks at four points (B, B1, C, D) was 2.96±8.19; 3.78±3;84; 3.06±4.44; 1.96±7.82, respectively. The highest pressure values are observed at the B1 level, the region of the lower leg with the most pronounced change in the local radius and an increase in the circumference of the lower leg in the position of the foot dorsiflexion [12]. In vitro stiffness was calculated from the degree of slope of the force/stretch curve.
As shown in fig. 5, Figure 5 Static Stiffness Index (SSI) of various compression stockings measured with TMT in vivo (pin vitro (pin vitro (not shown in graphs). and in measurements in vitro , and in measurements in vivo , the maximum stiffness values were obtained when using two stockings of the 1st compression class, dressed one on top of the other, and with a statistically significant difference compared to knitwear of the 2nd compression class when measured in vivo (pin vitro (p
Pressure gradient. All stockings showed a decrease in pressure from point B1 to point D both on wooden leg models and on the limbs of volunteers in both lying and standing positions (Table 2). On fig. 6Figure 6. Pressure values obtained when using knitwear of the 3rd compression class on the lower limb in the prone and standing position of the subject, as well as on a wooden model of the limb (DMK). the average values of the pressure created by the 3rd compression class knitwear on the limbs of volunteers in the prone and standing positions, as well as on a wooden model, are reflected.
At ankle level (point B) in vivo , the pressure was lower than when measured on a model limb, due to differences in the geometry of this anatomical region.
Talk
It is noteworthy that the indicated pressure ranges and classification of medical compression products into compression classes are based entirely on in vitro measurements of by the manufacturer. Single attempts were made to compare several measurement methods [13]. The present study demonstrated that, at least for the products tested, the stated pressure ranges satisfactorily matched the measurement results in vivo .
Test subjects. Healthy volunteers with different configurations of the lower extremities were selected for the study. Pressure and stiffness parameters measured immediately after putting on compression stockings do not differ between healthy subjects and patients with pathology of the venous or lymphatic systems. Since a good correlation was shown between the pressure values of the knitwear on the limbs of the volunteers and the wooden leg model, even severe lipodermatosclerosis would not have affected the results of the measurements obtained in the acute experiment.
However, if such studies are directly focused on the elimination of edema, it may be appropriate to re-measure the compression pressure and volume of the limb some time after putting on the knitwear.
Measurement methods and points. Based on a comparative study using three compression band pressure measuring devices, J. Dale et al. [14] recommended TMT for use in subsequent experiments. This tester is reliable in routine use and allows you to measure the pressure on the inner surface of compression stockings at several points simultaneously [7, 14]. The disadvantages of the device are its limited availability, applicability only for the state of rest and the impossibility of continuous measurement of pressure while walking.
For knitwear manufacturers, the area around the ankle is the reference for compression class and pressure range. level B. The stretch of the knitwear, measured with a dynamometer, is transferred to the surface of a cylinder with a circular cross section in such a way that theoretically it should be the same at each point of segment B.
In reality, segment B on the lower limb, corresponding to the cross section at ankle level, has the most variable curvature of all other limb segments. In fact, the pressure values measured in the posterior malleolar region are often lower than the pressure value at level B1, i.e. 8 cm higher (see Table 2), which emphasizes the importance of the local radius of the limb segment (according to Laplace’s law, local pressure is inversely proportional to the radius) [1] .
Pressure gradient. As shown in the table. 2 and in fig. 6, the wooden leg model, with its round cross-section, provides uniform pressure relief in the proximal direction. The pressure values coincided with the measurements of in vivo at the level of the maximum circumference of the lower leg (point C) and below the knee joint (point D), where the transverse section of the lower leg is close in shape to a circle and does not change significantly in the standing position. In vivo pressure values at point B are lower, which is associated with the location of the measurement point posterior to the ankle, where the contour of the perimeter of the limb is flat, and in some cases concave.
The greatest pressure difference in the standing and lying positions was determined at level B1 (see Table 2, Fig. 6), which indicates the optimality of this position for assessing the rigidity of knitwear.
Stiffness study in vivo . Rigidity can be defined as an increase in compressive pressure with an increase in limb circumference by 1 cm (due to muscle contraction) [8]. This parameter characterizes the extensibility of the tissue, which determines the effectiveness of the compression product in the standing position and when walking [8, 10]. Several experiments have shown that even at the same resting pressure, knitwear with higher stiffness is more effective in eliminating edema [3], reflux [2] and dynamic venous hypertension [1] in patients with chronic venous insufficiency. When the sensor is placed on the inner surface of the lower leg in position B1, the increase in pressure when moving from a lying position to a standing position is a simple indicator of stiffness, a static stiffness index [10].
This increase in pressure is due to a decrease in the local radius due to displacement (protrusion) of the muscle tendon (in accordance with the Laplace equation) and an increase in leg circumference during dorsiflexion of the foot with each step [12]. Plethysmography in the standing position with dorsiflexion and plantar flexion showed the dependence of the change in the circumference of the lower leg on the measurement point. In segment B1, an average increase in limb circumference by 8 mm was recorded, while in the proximal tibia, a decrease in circumference by 2–4 mm was determined [12]. Changes in the local radius due to displacement of the tendons during movement in the ankle joint are very individual. The high variability in the values of the static stiffness index mainly reflects significant individual differences in the shape of the lower leg in the standing position and when walking.
A greater increase in pressure was noted when using an inelastic material and a smaller one when using a pliable, elastic knitted fabric [6, 10].
The stiffness index of compression stockings is lower than that of short stretch compression bandages. Comparison of stiffness values is possible only when the same sensor is exactly installed in the same position [6].
An unexpected finding was that two stockings of the 1st compression class, worn one on top of the other, not only provided a higher pressure at level B1 than a stocking of the 3rd compression class (see Table 2), but also showed a higher stiffness coefficient as in measurements in vivo and in the in vitro tests (see Fig. 5). This phenomenon can be explained by friction between the two layers of the fabric of compression garments [12]. When the calf circumference increases while standing or walking, tangential stress is transferred to the fibers of the compression stocking. The friction between the rough surface of the knit layers prevents the increase in the volume of the lower leg in addition to the elastic stretch of the fibers of the fabric.
Compression pressure measurement validity in vivo . The pressure values obtained using a tester of medical knitwear on the limbs of volunteers not only agree well with those obtained on a wooden model (see Table 2), but also correlate with the calculated data on the force / stretch curves (see Fig. 4) . This contradicts the recently published data obtained by measuring in vivo compression pressure of class 3 knitwear using a resistive sensor, which did not exceed 15 mmHg. [15]. In this study, unfortunately, no attempt was made to calibrate the sensor or compare its readings with the reference method.
Our in vivo measurements of closely match the pressure ranges recommended in several international standards, measured not at point B, but at point B1, which is more reliable in this respect. To ensure a pressure gradient, the European Standardization Project recommends creating pressure at point B1 at a level of 70-100% of its value at point B [8].
This should be taken into account when comparing the results of measurements at point B1 in vivo and in vitro (see Figure 2).
Practical value for international standards for compression stockings. The following items need to be discussed with compression garment manufacturers:
– to characterize the different degrees of compression of knitwear, not compression classes, but pressure ranges in mmHg should be used;
– pressure ranges, which are currently only determined by various laboratory tests, must also be verified in vivo ;
– point B1 should be used for such measurements;
– in vivo measurements must be performed with the patient lying down and standing. The difference in values at this point can be used as a stiffness parameter;
– measurements of this kind should be performed in subsequent hemodynamic and clinical studies with testing of new developments or comparison of various devices;
– multilayer stockings are an interesting solution not only in terms of ease of use by patients, but also in terms of achieving high pressure and high stiffness.
The desired pressure can be matched to the periods of daily activity and rest by adding or removing layers of knitwear.
[1] Translator’s note. The authors do not correctly apply Laplace’s law. In accordance with this law, with an increase in the radius of a vessel with a flowing liquid, the pressure in it decreases proportionally, i.e. The pressure inside a vessel is inversely proportional to its radius. However, in this study, compression pressure (external to the limb) is considered, which, due to the stretching of the compression stockings, increases in direct proportion to the increase in the radius of the limb.
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