Patent Application
20160157601
A portion of the disclosure of this patent document contains material which is subject to copyright or mask work protection. The copyright or mask work owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright or mask work rights whatsoever.
This disclosure relates to furniture and in particular to a work support device and keyboard and mouse tray that is portable yet useful by users of chairs for either work or home environments, and specifically when using chairs that will force a chair user or occupant to sit back in the seat and to be in a reclined position by supporting and thereby controlling the position of the seat user's feet and legs relative to the seat pan and base to achieve a stable seated posture while working on a variety of computer platforms including, but not limited to, desktops, laptops, netbooks, tablet and smart phones.
Many attempts have been made over time to create devices that can be used by seated users of seats that recline yet force the seated user to sit all the way back in the seat. The present invention provides a portable work support and keyboard and mouse tray that is multi-positional and thus able to be oriented in one of a number of positions making its use by such a seated user a comfortable and rewarding experience.
As for chairs and foot rests, Larson, in U.S. Pat. No. 6,196,631, sets forth a variety of chair styles, including bench, Grandjean, Balan, Mandel, center-tilt and knee-tilt. He also noted that there were six footrest designs including horizontal rings, center column supported rings or rests, horizontal bars supported by the chair sear pan, chair spoke supports, separate floor mounted supports, and the floor itself. Thus, included among these six have been those in the form of separate footrests that are not at all part of or connected to the chair, but rather rest on the floor or another structure. Others have been built into the base as a ring or foot support that is relatively close to the floor on which the chair is resting. Others, as with salon chairs, have provided a foot rest that is adjusted by a handle to provide a foot rest that can move between a retracted position and an extended position, but not with the objective of having the seated person sit back in the chair, and not in a reclined position. Some have fixed a footrest with the seat itself or the seat pan so as to move in unison therewith (see, Cooper, U.S. Pat. No. 5,056,864). Still others have been provided for high chair seats by having a fixed footrest attached to the seat bottom, (van Hekken, U.S. Pat. No. 5,011,227), or to the central seat post. It is important to note that if one's feet are placed correctly in a footrest that is itself correctly located on a chair's structures, then the placing of a users feet in a footrest will create a tactile input/cue that will lead to the desired (muscle) motor output and achieve the desired result of having the seated user sit all the way back in the chair.
While there have been many attempts at creating an environment for achieving a desired seated user position, those have not been specifically directed to the objective of getting the seated user sitting fully into the chair, and thereby actually use and obtain the benefit of a chair's design on the seated posture of the user, as well as optimizing seated posture while interacting with a computer. While some of the prior attempts have sought to provide user comfort, to position the user into a more neutral posture, or to position a seated occupant in a more equitable weight distribution position within the chair, they have not attempted to make adjustability specific to the desired end result of making that seated user to sit all the way back in the chair and then to have that user remain all the way back in the chair while in a reclined position while interacting with a computer. There has been some adjustability, but only to provide comfort for the user and not specifically designed to provide a way to fit each of a wide range of individuals, and to facilitate the seated user actually taking advantage of the chair's design and structure and, as just noted, to sit all the way back in the chair every time and throughout the period of use while the user is in the chair and is using a computer.
As previously noted, the invention relates generally to field of furniture and more specifically to an ergonomic chair and associated structure, as well as an aftermarket support structure, that optimizes musculoskeletal energy efficiency, reduces muscle fatigue and decreases low back pain of a seated individual and when properly positioned in an ergonomic chair.
There is now a 23 billion dollar a year office manufacturing industry in the United States. Included within the sales by that industry is seating equipment, which includes ergonomic desk chairs, which is expected to make up the largest product segment for the industry. In the five years to 2013, this specific segment's share of revenue has increased to 33.1% fueled by growing concerns about health and safety in the office stemming from the prolonged periods of time users are spending seated while working on computers. The time and financial cost of the neck, back and upper extremity pain of the typical office worker, as well as other musculoskeletal disorders (MSD's) principally stemming from prolonged inefficient sitting postures while using a computer, has risen to epidemic proportions. Chronic low back pain disability is the single most expensive benign condition that is medically treated in industrial countries, costing the health care system more than $65 billion a year. Back pain is also the number one cause of disability in people under the age of 45, is the third leading cause of disability in people over the age of 45, and comprises approximately 40% of all compensation claims made in the United States. Current medical studies suggest that back pain will affect more than 80% of the population at some point in their life. With the rapid development of modern technology, sitting at a computer, at work and home, has now become the most common position assumed by most people in today's industrialized nations. And the connection between pain and prolonged sitting in office chairs, even “ergonomic” ones, is well documented. (Li G, Haslegrave C M. Seated postures for manual, visual and combined tasks. Ergonomics. 1999 August; 42(8):1060-86.).
The term “ergonomic” first entered the modern lexicon when Wojciech Jastrzbowski used the word in his 1857 article “The Outline of Ergonomics; The Science of Work, Based on the Truths Taken from the Natural Science”.
In the late 1970's, the study of human-computer interaction (HCI) was born, involving the study, planning, and design of the interaction between people (users) and computers. Attention to human-machine interaction became important because poorly designed human-machine interfaces began to lead to many unexpected problems, including an epidemic of low back pain and other MSD's, even before users spent as many hours per day working on computers as they do now. Today, the word “ergonomic” design has come to mean the applied science of equipment and workplace design intended to maximize productivity and efficiency by reducing operator fatigue and discomfort.
Over the last two decades, one focus of ergonomic office chair design research has shifted from identifying the best single sitting posture, towards a more dynamic view of sitting and movement, in an effort to keep the user in motion, even while seated. While the emphasis on movement has helped avoid some ergonomic risk factors related to inefficient prolonged sitting without breaks, it also confuses the issues. While movement is critical for the health of the user's musculoskeletal, skin, and cardiovascular systems while seated, not all movements and postural adjustments are equally beneficial, with some movements far more detrimental than others. Taken to extremes, a strict emphasis on seated movement can introduced new risk factors for the sedentary, mainly the persistence of chair operator error (underutilization of the chair's ergonomic benefits), along with some form of MSD symptom development for nearly every consumer of this product. A 2012 systematic research study looking at assessing the effects of dynamic sitting on trunk muscle activation found that dynamic sitting did not significantly change trunk muscle activation in any of the studies reviewed. Major chair manufacturers OFM's now advocate for movement away from the chair while working, including standing, walking, taking frequent breaks, even using a standing or treadmill desk, to break the cumulative repetitive trauma that originates from sitting incorrectly for prolonged periods, mostly stemming from operator error. In this regard, operator error means seating mistakes by a chair user. However, research shows that not sitting or standing, alone, is not a panacea solution to decreasing MSD's and low back pain (“LBP”) for computer users. Standing for prolonged periods may introduce a host of other MSD's stemming from poor standing posture, provoking accelerated rates of degenerative musculoskeletal overuse conditions, particularly in the low back and knees, for many who attempt to work at a computer standing instead of sitting. Sitting requires far less energy expenditure than standing overall, deeming it a more ergonomic position for prolonged computer work. Thus, an ergonomic computer work station designed to reduce the frequency and duration of operator error while seated is needed and is achieved by the present invention.
For the purpose of studying the seated human body at work, ergonomists, medical personal and manufacturers have identified three possible user postures based on the location of the body's center of mass (COM) over the body's base of support (BOS), as are shown in
Multiple studies over the last 50 years have shown that reclining seated posture is the most ergonomic, with back extensor activity and intervertebral disk pressure significantly lower, especially when the user's natural anterior lumbar curvature (lumbar lordosis) is supported, and the pelvis is stabilized in a neutral position. The pelvis is best stabilized by its being tightly wedged into the seat back/seat pan junction in the chair proximally, and by both feet firmly planted on the floor or on an angled platform, thereby creating a triangulated stabilization effect for the user's lumbo-pelvic region.
Forward leaning posture is the least ergonomic of the three postures and, therefore, the most physiologically detrimental, with upright posture coming in a close second. “Edge sitting”, often coupled with the presence of a sustained rounding of the low back known as “posterior lumbar curvature” (lumbar kyphosis), is one of the most common and detrimental of chair operator errors. It describes how a user is sitting when their pelvis is not all the way back in their chair, and the torso is unsupported, thereby underutilizing one of the most important benefits that today's ergonomic chairs can offer, lumbo-pelvic stabilization. A user can make attempts to maintain their neutral lumbar lordosis while edge-sitting, but studies have shown that most users who attempt to sit upright without a back support in a conventional ergonomic chair inevitably succumb to forward leaning and eventual sustained kyphotic posture. Studies have also shown that sustained and/or repetitive lumbar kyphosis when seated causes creep of the viscoelastic tissues of the lumbar spine, as well as accelerated hip flexor and hamstring muscle tightness. This can result in immediate and residual laxity of the lumbar joints, and an over stretch of the facet joint capsules, both of which are contributing factors to the biomechanical destabilization of a user's lumbar spine, and the resultant onset of spine degenerative disorders such as stenosis and arthritis, and potentially chronic LBP.
Other studies have shown that maintaining a reclined position, with the lumbar lordosis supported and the pelvis being in neutral condition, in conjunction with the placement of technology (monitors, keyboards, etc.) at appropriate proximities to the user, is the most physiologically efficient position for a user while seated in an ergonomic chair and interfacing with a computer. Accordingly, many of today's ergonomic chairs incorporate lumbar and pelvic support features in the seat back and seat pan, as well as seat tilting mechanisms and tilt locks, designed to encourage a user to sit all the way back in their seat for prolonged periods, in recline, in order to best utilize the benefits of the chair's design. Despite these significant advantages, many if not most chair users do not sit in a reclined position and most usually this is due to operator error that is permitted by the chair's design itself in combination with poor placement of technology relative to a user.
The inclination in present cultures is to look at the body as if it was constructed solely by means of compression. We tend to think of the skeleton as another version of the stone wall with the bones stacked one on top of the other, each relying on the ones below. LPF (lumbopelvic-feet) triangulation redirects the forces to the ground via the legs and feet, thereby immediately reducing the compression forces through the LP region. For a seated individual without the support of one's legs, that user's super-incumbent weight is transferred to the LP region and to the seat pan only, which in turn endure higher, chronic compression forces that could otherwise be diverted away from the LP region through simple LPF triangulation.
Since most chair-use related LP MSD's (muscle-skeletal disorders) are a consequence of cumulative compression forces over time, then a work station system that could effect more frequent LPF triangulation would serve to significantly reduce compression forces at the LP region for high frequency/duration computer users. It would certainly help decelerate LP region MSD onset, depending on the frequency of: (1) the occurrence of LPF triangulation; (2) backrest angles averaging 25 degrees posterior to vertical, and (3) the appropruiae positioning of a monitor, keyboard and aa pointing device. Both would further divert user weight off seat pan and LP region and onto seat back. If the chair back angle is more than 30 degrees posterior to vertical, then the benefits of a reclined angle of a computer user are trumped by the disadvantages of a poor position, including too much resultant flexion in the neck to maintain eye contact with a computer screen, and a decrease of oxygen intake, causing user sleepiness, as a result of increased gravity on the lungs reducing lung expansion during inhalation. As noted, the present invention involving the chair base helps the seated user to do all three more often.
With the foregoing in mind one can then say that:
“optimal 1p stabilization=mechanical triangulation+tensegrity.”
However, this view of body as an inert load, and how best to stabilize it by a reduction in gravity-related compression forces is only half accurate. The human body actually uses both compression and tension in a manner known as “tensegrity.”
Tensegrity is a term coined by architect Buckminster Fuller in 1929 when he combined the words “tension” and “integrity” to describe structures whose integrity rely on local, discontinuous compression members (for us,humans, our bones) floating in a sea of continuous tension (muscles and connective tissue). A human's primary connective tissues include muscles, tendons, ligaments, joint capsule tissues and, in the spine, intravertebral discs. The bones push outward against soft tissues that pull in. Bones resist compression and soft tissues resist tension.
In the world of physical therapy, this concurrent tensing of the muscles around the joints of a fixed limb is described as a CKC (closed kinetic chain) muscle activation. CKC muscle activation around the LP joints decompresses and stabilizes the region by placing all the soft tissue around these central skeletal joints in tension at once. One can imagine the mechanism of muscle tension-induced LP decompression that can happen in a seated, or standing person. This is also the mechanism of LP decompression that occurs when a human does a handstand or a cartwheel using the arms as the support structures instead of the legs.
In 1955, Dr. Arthur Steindler, an orthopedic surgeon, described an analysis of human movement. Dr. Steindler suggested that the extremities should be viewed as a series of rigid, overlapping segments and defined the kinetic chain as a “combination of several successively arranged joints constituting a complex motor unit.” Dr. Steindler defined closed kinetic chain exercise as a condition or environment in which the distal segment of a human limb meets considerable external resistance (as is the case with the footrest of this invention) that restrains movement. In a CKC movement, the distal end of the extremity is fixed, emphasizing joint compression along the joints within the kinetic chain and, in turn, stabilizing the joints by diverting the compression away from the joints and onto the tension tissues surrounding the joints, instead. This is the mechanism of leg muscle activation while seated in a chair pushing against a fixed surface (e.g., a properly attached foot rest).
The only angle that really matters for a seated individual is the backrest angle, but for the seated individual using a computer, angles of the neck, shoulder, elbows and wrists matter as well.
As long as a seated chair user is comfortable, and can place their feet comfortably onto the footrest platform of this invention, so as to not cause a posterior rotation at their pelvis, or a rounding of the low back, then there will be better control over and a better relationship developed between desired hip, knee and ankle angles. In addition, the longer one activates the leg's anti-gravity muscles while using the present invention by pushing against the securely attached foot rest platform or plate then one collateral benefit of doing such leg muscle activation using the present invention is to achieve the benefit of less tightness in the seated user's hip flexors and hamstrings by virtue of a chronic activation of both muscle groups' antagonist muscles (glute max and quads, respectively) on a fairly frequent basis. A necessary consequence of muscle activation is antagonist muscle relaxation (called pull-counter pull).
Both upright and forward leaning positions will be considered herein collectively as awkward postures. Both have been shown to accelerate pathological MSD processes as compared to reclined positions. People performing computer related tasks in either an office, home, hotel, café or other environments continue to exhibit one or both of these awkward postures throughout most of their work day. The cause of such awkward postures is due to operator error and is most usually being triggered by the instinctive or subconscious and involuntary need of the seated user to view their computer screen, and to type on a poorly located keyboard and pointing device, even if the resultant posture was awkward.
A human's capacity to maintain balance is defined as the ability to maintain the body's COM over its BOS. To maintain balance, a properly functioning human balance system offers the brain three forms of sensory input to integrate before generating a subconscious, instinctive postural adjustment, also known as a “balance reaction” or a “motor output”. The three sensory inputs our bodies provide are (1) visual input, (2) vestibular input, and (3) proprioceptive input. Visual input, collected in the eyes, tells our brains what we see, or want to see. Vestibular input, gathered at our vestibular organs located between our ears, relays information related to sound, rotation, linear movement, and equilibrium. Proprioceptive input, gathered from pressure and stretch receptors in the skin, muscles and tendons, provides the brain information regarding the body's position in space. Together, these three sensory inputs gather information for us to examine before our brain generates an instinctual postural adjustment with the end goal of maintaining one's COM over its BOS. There is no better example of sensory input leading to an intuitive balance reaction than when one trips over something while walking, thereby triggering a swift, instinctual, and awkward postural adjustment!
If, for whatever reason, one or more sensory system's capacity to provide input is limited, then the brain will make motor output decisions without the benefit of the missing input's data. In other words, the brain will generate postural adjustments based only on the sensory input actually being provided. If an office chair does not provide a consistent means for the seated occupant's feet, and the associated legs, to provide proprioceptive input to the brain, then the brain will rely mainly on visual and vestibular data in triggering a postural adjustment in achieving the user's goal of looking at their computer's screen. And, if one's COM is already close to being positioned above the pelvis or anterior to it relative to vertical, then an instinctive migration to an unhealthy posture is triggered, and another is not triggered until the user senses musculoskeletal discomfort, or conscious override. Thus, it may seem like the eyes always win, but that is only because the critically important proprioceptive sensory input from the user's feet and ankles are not always in the game. A significant design malfunction of every ergonomic office chair is that the triggering of operator error, and the resulting poor sitting posture, is not primarily due to the location of the computer screen being viewed, but rather due to the lack of continual sensory input from the feet and ankles to help each seated user reduce their frequency of instinctive migration to awkward postures.
The present invention provides this desired sensory input from the feet and ankles on a continuous basis. It minimizes operator error, it increases the frequency of healthier instinctive postural reactions by supplying the sitter's brain with a far greater amount of lower extremity proprioceptive input to consider, on a consistent and on-going basis while seated, and it allows increased use of the lower extremity muscles. Collectively. this reduces the inefficient overuse of back extensors and upper extremity muscles. In addition, the present invention widens the BOS surface area to include the feet, therefore reducing PSI through the back, buttocks, and thighs. It also reduces compressive loads through the lumbar spine, thereby facilitating reduced rates of spinal shrinkage. Further, it decreases sustained and/or repetitive lumbar kyphosis, therefore reduces pathological creep of the viscoelastic tissues of the lumbar spine, and it decreases hip flexor and hamstring muscle tightness accelerated by sustained and/or repetitive lumbar kyphosis. Finally, the present invention can be used as a therapeutic intervention, as part of a greater plan of care, in the medical treatment of patients with signs and symptoms of prolonged inefficient posture related MSD's. When used in conjunction with adjustable technology for holding equipment, such as a monitor, a keyboard and mouse, the present chair and foot support invention, or the aftermarket foot support assembly in conjunction with the keyboard tray or work support, permits a seated individual to be placed in a desirable reclined tilt angle between 10 and 45 degrees from vertical, dictated by user preference and proximity of technology, that will optimize energy, reduce muscle fatigue, decrease lower back pain, and render the work place much more inviting.
From an ergonomic viewpoint, of a seated chair user, the user's two feet and pelvis is what triangulates stability. A major part of maintaining such stability, especially in the desired reclined position, and to help avoid operator error and awkward seating positions, is to provide stability for the user's feet. When a computer user's pelvis is supported using the legs, knees and ankles and feet, it is impossible to slouch unless he technology is misplaced.
The present invention also permits a seated user to sit fully back in the chair, thereby increasing the time a user actually sits all the way back in their chair and thus enables the seated user and one's back to fully benefit from the chair's design and to achieve the desired seated posture.
Another and equally important feature of the present invention is that once fitted and positioned to an individual's anthropometric needs, that is achieving the desired reclined position relative to the work environment including the seated user's leg length, the desk's height, the monitor's height, and so on, the pelvis/foot triangulation stabilization effect for that seated user will be maintained, even in recline. This triangulation in recline approach completely prevents the sitter from slouching for sustained periods and eliminates the foregoing operator error occurrences and awkward positions.
As noted, it is important for the present invention that a seated user be in a reclined position for chair use, whether in a home or office environment. When most people recline, depending on their height and their chair's tilting mechanism, their feet come off the floor. At that point the feet/pelvis stabilization triangle is disrupted, and that person is no longer experiencing all the chair's benefits. When one's feet dangle, one intuitively sits back up (and usually forward of vertical) in order to re-attach their feet to a solid surface, sacrificing the contact their back makes with the chair, causing the “edge-sitting.”
For shorter people, the off-loading of their feet occurs earlier in the recline process. For taller people, this happens with greater degrees of recline. If a tall person's hip flexors or hamstrings are tight, then a deep recline will be uncomfortable in the low back, even if their feet are technically still on the floor. Tight hip flexor and hamstrings promote lumbar bending with recline, rather than “hips opening up,” which will cause a tall person to sit back up just as quickly. So a tall person, too, needs to be able to recline with their feet position also under control to thereby allow them to also stay all the way back in their chair, in work recline, and be able to remain that position for longer periods of time.
The invention is better understood by reading the following detailed description with reference to the accompanying drawings in which:
To gain a better understanding of the invention, preferred embodiments will now be described in detail. Frequent reference will be made to the drawings. Reference numerals or letters will be used throughout to indicate certain parts or locations in the drawings. The same reference numerals or letters will be used to indicate the same parts and locations throughout the drawings, unless otherwise indicated.
The embodiments hereafter being described will be with respect to an office work environment, or to any work environment where a user will be seated in a chair and interacting with a computer of any form, including, for example, but not limited to a desk top computer, laptops, netbooks, tablets, ipods, ipads, smart phones and/or hand held devices, and it should be understood that the present invention applies equally well to chairs designed for home, outdoor or other environments. The scale of the embodiment, therefore, is to be understood with respect to this type of article and these types of work environments. It is to be understood as well, however, that the invention is applicable to other articles and its scale can vary accordingly.
Turning now to
The work supports or trays 10 or 10-1 can be constructed using a variety of approaches. For example it could be formed from a laminated structure that is cut into a desired shape. Alternatively, for example, it could be molded from a moldable material including plastic materials, thermoplastics, synthetic or semi-synthetic resins, organic resins, polymers, polyamides, polyolefin, polyurethanes, polycarbonates, polystyrene, compressed wood fibers, wood, medium density fiberboard, metal, or other man made materials or combinations of materials. The lower portion, which will provide a resting area for a user's forearms, can be left uncovered, or provided with an upper or outer surface of fabric, or an antifriction material, or of a metal or soft foam.
The liner 60 is preferably a molded, one piece element and can be fabricated from a soft molded material, for example, a foam, polyurethane foam, self skinning foams, or other soft plastic material. It is also possible to include a fabric as the exposed surfaces 82 and 85, or surfaces 82/85 could be formed from an anti-friction material, for example a rubber or soft plastic layer, or that material could be an over laid surface as shown in phantom at 90 in
As discussed above, the positioning pillow 100 has upper and lower chambers 130 and 132, respectively, as shown in
Much of the medical research of today focused on ergonomics, human-computer interaction and the resultant musculoskeletal disorders (MSD's) biomechanically inefficient posture can provoke, advocate for a separation of the computer monitor from the keyboard and pointing device to allow for less orthopedically stressful wrist, elbow, shoulder, neck, middle, and low back angles. It is important to note that the primary purpose in combining an attached footrest and detached keyboard tray is that, together, these components most easily facilitate the sitter's separation of computer screen or monitor from keyboard and pointing device, and the sitter's resultant high degree of biomechanically neutral posture while interacting with their devices of choice in addition to all the leg muscle activation benefits that having an attached footrest provides.
If a sitter is using the attached footrest, for example, but keyboarding on a keyboard tray located anywhere but in the general vicinity of their lap, then studies have shown that they will forego comfort and neutral posture to lean forward/hunch over to reach their keyboard and pointing device. Or, if a seated computer user places their laptop on their lap to work, thereby NOT separating keyboard from monitor, then the resultant excessive neck flexion (downward neck bending) to see the screen will cause neck pain and pathology, such as “text neck”, over time.
If a sitter is holding their computer tablet in-hand, again, not separating their monitor from keyboard, then the resultant posture can include excessive neck flexion, in addition to excessive neck rotation or twisting, depending on how the user is holding the device, and in which hand. This combining of excessive neck flexion and rotation has shown to significantly accelerate degenerative processes at the neck and upper extremities. Thus, it is simple to understand the physiological need for chronic computer users to habitualize the practice of separating the monitor from the keyboard and pointing device, as much as possible, as soon as chronic computer use occurs in one's life, which is happening far sooner in the life cycle of children born in industrialized nations today.
At minimum, to achieve a biomechanically neutral position while interacting with a computer, the most important feature is to have the keyboard and pointing device separated from the monitor, and to have the detached keyboard tray in the general vicinity of one's lap. The monitor/computer screen can be placed one arm's length away from the users eye's, with minimal neck bending, by a host of conventional means including, but not limited to, a standard or height adjustable notebook/monitor/tablet riser, a stack of books or reams of paper, or by simply placing the screen or monitor atop a static or height adjustable table. Most recently in office settings, articulating monitor arms are the tool of choice for correct monitor height and proximity to the seated user.
Thus, some degree of biomechanically neutral posture and comfort can be achieved with the detached keyboard tray, alone. However, optimal biomechanically neutral positioning while seated using a computer is best achieved when the detached keyboard tray is used in conjunction with the attached footrest designed to increase leg muscle activation and the time spent in neutral by physiological means and methods described elsewhere in this application.
Thus, by placing the keyboard tray in the right place for the user to keep their feet on the attached, tension resisting footrest, while remaining in overall neutral postural angles from the feet and upwards, the sitter's capacity to contract the large postural support muscles in the legs while seated, including the glutes and quads, has also proven to produce a suite of beneficial biochemical molecules. Most notably, the activation of these muscles activates an enzyme called lipoprotein lipase, which acts as a virtual vacuum cleaner for fats in the blood stream. When these muscles remain inactive for too long by virtue of, for example, prolonged sitting without breaks, even in neutral, lipoprotein lipase activity becomes virtually nonexistent, eliminating the body's ability of their muscles to remove noxious fats from the bloodstream, as well as a significant decrease in HDL cholesterol, aka the “good” cholesterol. In fact, research has shown that just a few hours of sitting without breaks suppresses a gene that helps keep your cardiovascular system healthy by controlling inflammation and blood clotting. Research has shown that after just one day of sitting, exercise does not turn the gene back on, even for runners. What has shown to turn this gene back on for sitters is periodic and routine breaks from sitting.
Thus, leg muscle activation and biomechanically neutral posture while seated does not exclude the sitter's requirement to takes frequent breaks from sitting to help decelerate the degenerative effects and disorders prolonged sitting can create in other systems of the human body besides just the musculoskeletal. Studies have found that simply interrupting one's sitting time with short breaks of just standing, pacing or walking slowly has beneficial effects. Pinpointing just exactly how long or frequent these breaks need to be is still up for investigation. More recent research show signs of improved glucose metabolism with 1 minute and 40 seconds of pacing every 30 minutes, for a nine-hour sitting period, as well as 2 minute bouts of light intensity walking every 20 minutes throughout a five-hour sitting period. In short, getting up and either standing or walking around for about two minutes at least twice per hour can help keep your skeletal muscles turned on and lower the risk of disease. A battery operated timer or alarm can help acclimate sitters to the frequency and duration of required rest breaks for more healthful, and less detrimental prolonged interaction with their computers and other electronic devices.
With reference to
Turning to
The roller member 360 has a base frame 362 onto which four wheels or casters 364 are suitable attached. An upstanding frame 366 includes front vertical bars 368 and 370, top bars 372 and 374, and rear vertical bars 376, only one of which is shown. There can also be cross bars, for example as shown at 378 for a rear bar that would extend between the bottoms of rear bars 376, and a front cross bar 380 that would extend between front bars 368 and 370. An adjustable foot rest 294 that can be positioned at a variety of angles on frame 362 as it was in the
When introducing elements of various aspects of the present invention or embodiments thereof, the articles “a,” “an,” “the” and “said” are intended to mean that there are one or more of the elements, unless stated otherwise. The terms “comprising,” “including” and “having,” and their derivatives, are intended to be open-ended terms that specify the presence of the stated features, elements, components, groups, and/or steps, but do not exclude the presence of other unstated features, elements, components, groups, and/or steps and mean that there may be additional features, elements, components, groups, and/or steps other than those listed. Moreover, the use of “top” and “bottom,” “front” and “rear,” “above,” and “below” and variations thereof and other terms of orientation are made for convenience, but does not require any particular orientation of the components. The terms of degree such as “substantially,” “about” and “approximate,” and any derivatives, as used herein mean a reasonable amount of deviation of the modified term such that the end result is not significantly changed. For example, these terms can be construed as including a deviation of at least +/−5% of the modified term if this deviation would not negate the meaning of the word it modifies.
While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
