This invention relates to devices that relieve pressure on a kneeling person, and more particularly to such devices that include a seat that supports a portion of the worker's weight while he is kneeling.
There are many occupations such as shipbuilding, mining, plumbing, carpet and floor installation, construction, repair, services, and auto body repair in which people must spend a considerable amount of time kneeling or squatting. Such people put 70% of their body weight on a few cubic centimeters of the tibia and patella while kneeling as opposed to putting 22% of their body weight on each knee while walking. Prolonged kneeling increases a person's risk of developing musculoskeletal knee disorders such as osteoarthrosis, meniscal lesions, chondromalacia, and bursitis. Also, it is uncomfortable to maintain a kneeling position for a long period, which can decrease productivity of workers.
Various studies have been made on injury to the knee from prolonged kneeling or squatting. Elsner et al., [Knee Joint Arthroses and Work-Related Factors] Soz Praventivmed, 1996; 41(2):98–106, found that men who worked on their knees had a significantly greater chance of developing arthrosis of the knee. Cooper et al., Occupational Activity and Osteoarthritis of the Knee, Ann Rheum Dis 1994 February; 53(2):90–3, found that men whose job entailed more than 30 minutes per day of squatting or kneeling had a significantly greater chance of developing osteoarthritis.
Kivimaki et al., Knee Disorders in Carpet and Floor Layers' and Painters, Scand J Work Environ Health 1992 October; 18(5):310–6, and Occupationally Related Ultrasonic Findings in Carpet and Floor Layers' Knees, Scand J Work Eviron Health 1992 December; 18(6):220–2, found that osteophytes of the patella were more common among carpet and floor layers than among painters, and that self-reported knee bursitis was also more prevalent in carpet and floor layers. Furthermore, ultrasonography of the knee showed thickening of the prepatellar or superficial infrapatellar bursa in 49% of the carpet and floor layers and 7% of the house painters. This ultrasonographic finding was associated with knee pain in kneeling postures.
Thun et al., Morbidity from Repetitive Knee Trauma in Carpet and Floor Layers, Br J Ind Med 1987 September; 44(9):611–20, found that self reported bursitis and arthritis of the knee were more common in terazzo workers who kneel than in other groups who seldom kneel. Coggon et al., Occupational Physical Activities and Osteoarthritis of the Knee, Arthritis Rheum 2000 July; 43(7):1443–9, found that the risk of developing knee osteoarthritis is higher for people who kneel or squat for prolonged periods of time. Sandmark et al., Primary Osteoarthrosis of the Knee in Men and Women as a Result of Lifelong Physical Load from Work, Scand J Work Environ Health 2000 February; 26(1):20–5, found that among men there is an association between kneeling and knee osteoarthrosis.
Kasch and Enderlein, [Damage to the Knee Joint in Ship Building] Beitr Orthop Traumatol 1986 October; 33(10):487–94, reported that x-rays showed that there was an increased occurrence of knee injuries in welders as compared to other groups.
A study of ergonomics and shipbuilding by the National Institute for Occupational Safety and Health (NIOSH) found that kneeling or squatting for long periods of time may be related to the finding that the incidence of lower extremity musculoskeletal injury in domestic shipbuilding and ship repair industries is 300–220 percent higher than in the overall manufacturing sector. NIOSH also found that knee injuries have the highest cost compared to other injuries per employee per year.
The health risks and costs associated with prolonged kneeling and squatting have led to efforts to prevent such injuries. Such efforts have recognized the need to reduce the amount of flexion in the knee and the amount of contact stress applied to the facet of the knee joint. Efforts to reduce such stress would also reduce forces on the internal knee and lower back that are known risk factors for musculoskeletal knee disorders. Unfortunately, many of the devices that have been used in the past to relieve pressure on the knees are bulky, heavy, and of questionable durability.
U.S. Pat. No. 3,025,526 discloses a kneeling device that attaches to a user's leg. It includes a kneepad that is attached to the user's knee by straps that are positioned below the knee and in the ankle region. When a user is in the standing position, the device unfolds and rests partially on the thigh. This device is bulky and restricts a user's movements while walking. Also, it is essentially a kneepad and does not take the weight off the user's knee.
U.S. Pat. No. 4,772,071 discloses a kneeling device that inlcudes a kneepad attached to a seat. The device is attached to the lower leg. The device is, however, bulky and must be removed when the user wants to stand or walk because it hampers movement.
In U.S. Pat. No. 5,865,507, a rectangular base has a seat and a pair of coextensive troughs with knee-wells located at the ends of the troughs. A user sits in the seat and places his legs in the troughs and his knees in the knee-wells. The device is also bulky and can only be used on unobstructed horizontal surfaces. Furthermore, it is not easily moveable, and every time a user wants to change his position, he must stand up and lift the device to move it. The device is heavy and can cause tripping because of its bulkiness.
U.S. Pat. No. 6,089,667 describes a motorized knee support device comprising a rigid plate that is covered with a pad. The plate is mounted on a base by a threaded post, and the height of the plate can be adjusted by a gear system. The device is relatively difficult to mount because it requires a person to stand in front of the unit, squat or kneel down, and then extend the leg back underneath the support. It is also not portable, but rather is freestanding, heavy, and bulky.
U.S. Pat. No. 5,577,800 discloses a work seat that is used while in a kneeling position. The device has a base with wheels, an adjustable seat, and a handle. The device allows the user, while kneeling, to support body weight primarily on the device rather than on the knees. The device, however, is bulky, heavy, and can only be used on unobstructed surfaces, thus there are many places where it cannot be used. Also, the wheels only move forward and backward. Thus the user must dismount when the device needs to be moved laterally.
In U.S. Pat. No. 5,380,021, a mobile knee support includes a pair of slings supported by a pair of casters. The slings support the knees of the user, and the casters allow for mobility. Since the user's weight is distributed on the knees, the device does not reduce forces on the internal knee and lower back. Also, the device does not reduce flexion in the knee joint. Since there are wheels, it can only be used on a relatively level, smooth, and unobstructed surface.
A sit-kneel chair is shown in U.S. Pat. No. 4,589,699. The chair has a seat portion and a knee support which are designed primarily to relieve tension of the lower back. Since the user sits in an upright position, the device is not suitable for use when kneeling close to the ground.
U.S. Pat. No. 4,377,309 discloses another support device having a seat attached to a base, for supporting the user in a sitting-kneeling position.
Balans Produkter AB produces a device under the trademark Balans Snap Sit, which includes a knee-well attached to a seat. The device does not fold while attached to the leg, and it is bulky and restricts movement while walking. It is also flammable, not sufficiently durable for regular use by workers in heavy industry, and has knee-wells that can gather materials, such as weld slag.
There is thus a need for a device that relieves pressure from the knees while kneeling, is easily portable, is attachable to the body, and can be moved automatically by the user without the user having to pick up the device and manually move it to a new position. There is also independently a need for a device that that is nonflammable and durable, so that it can be used in heavy industry and can be used on horizontally constrained and uneven surfaces. It would also be helpful to provide such a device that is comfortable to use while kneeling.
A wearable knee support device for relieving pressure on a user's knee is disclosed. The device includes a body adapted to receive the leg of a user. A seat member is pivotally connected to the body and adapted to receive the weight of the user. A base member is also pivotally connected to the body and adapted to support the device in an unfolded position. At least one linking member connects the seat member and the base member. Moving either the seat member or the base member causes the linking member to rotate both the seat member and the base member from a folded position adjacent the leg of the user to an unfolded position. The base member can then rest on a horizontal surface and the seat member can support the user's weight.
In some embodiments, this kneeling device reduces the amount of flexion in the knee joint and the amount of contact stress applied to the facet of the knee joint, to reduce forces on the internal knee and lower back.
Referring to the drawings, the wearable kneel-sit support device 10 includes a U-shaped body 12 adapted to receive the leg 14 of a user. As illustrated in
As shown particularly in
The U-shaped body 12 includes the pair of parallel side members 20a and 20b, which have rounded ends 28a, 28b, 30a, and 30b (
The seat members 22a, 22b are respectively attached to a first pair of legs 38a and 38b (
The first and the second legs 38a and 38b support, at their distal ends 44a and 44b, the first and second seats members 22a and 22b. The legs 38a and 38b can be welded to the seats 22a and 22b, or they can be formed as a single piece. The first and second seat members 22a and 22b are shown as being generally oval shaped in the illustrated example. Holes 50 are made in the seats members 22a and 22b and the pair of legs 38a and 38b in order to lighten the device 10. The seat member 22 can be made from aluminum or reinforced plastic. The first and second seats 22a and 22b are padded at 52 to increase the comfort of the user when he places his weight on them.
The base member 24 is comprised of a second pair of legs 54a and 54b attached to a generally horseshoe shaped base 56. See
The first and the second legs 54a and 54b are attached at their distal ends 61a and 61b, respectively, to the base 56. See
First and second linking members 26a and 26b link the pair of legs 38a and 38b of the seat member 22 to the pair of legs 54a and 54b of the base member 24. See
Similarly, the second linking member 26b is attached at a first end 64b to the proximal end 46b of the second leg 38b of the seat member 22. The second linking member 26b is attached at a second end 66b to the second leg 54b of the base member 24 at a position 68b intermediate its distal and proximal ends 61b and 58b, as shown in
Referring to
The device 10 is shown in the unfolded position in
Referring to
In use, as shown in
Since the device 10 is compact and relatively lightweight, the user can walk with the device 10 conveniently attached to the lower leg 14. When the user wants to kneel, an optional kneepad 100 (
In this orientation, the base 56 and the generally oval shaped seats 22a and 22b are substantially perpendicular to the U-shaped body 12, and the buttocks are supported by seat members 22a and 22b, so that the user's weight is partially on the kneepad 100 and partially on the seats 22a and 22b, thus relieving pressure on the knee. When the user wants to move or rise from the kneeling position, he stands up and pivots the seat member 22 and the base member 24 into the body 12 as illustrated by the dashed lines in
Referring now to
The attachment members 86, 86′ in the illustrated configuration are coupled to each of the first and second side members 20a, 20b, respectively, using respective brackets 112. The brackets 112 can be secured to the first and second side members 20a, 20b in a conventional manner, such as with the illustrated screws 114. Although not shown in the drawings, the brackets 112 also can be implemented in the embodiment of
Although the present disclosure has been described in considerable detail with reference to the drawings herein, other embodiments are possible. For example, the body 12, in the illustrated example is U-shaped, but other shapes can also be employed. Although the seats 22a and 22b are shown as being oval, they can have other shapes, such as round, square, rectangular or other configurations. A single seat can also be used, for example a single support spanning both buttocks or a single seat member that supports only one of the buttocks. In the illustrated example, holes 50 are made in the device 10 in order to lighten it, but the device can be made without the holes. The securing members in the illustrated example are shown as being shoulder bolts, but other securing members can be use such as pins and other fasteners.
The base 56 is shown in
This is the National Stage of International Application No. PCT/US02/16790, filed May 28, 2002, which claims the benefit of U.S. Provisional Patent Application No. 60/300,315, filed Jun. 22, 2001.
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/US02/16790 | 5/28/2002 | WO | 00 | 12/19/2003 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO03/000093 | 1/3/2003 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
2432565 | Ferguson | Dec 1947 | A |
2631652 | Bannister | Mar 1953 | A |
3025526 | Ramon | Mar 1962 | A |
3863978 | Gillings, Jr. | Feb 1975 | A |
4377309 | Mengshoel | Mar 1983 | A |
4589699 | Dungan | May 1986 | A |
4772071 | Richards | Sep 1988 | A |
5073986 | Farrago | Dec 1991 | A |
5125479 | Nemes et al. | Jun 1992 | A |
5380021 | Doherty | Jan 1995 | A |
5577800 | Earl, Jr. | Nov 1996 | A |
5865507 | Earl, Jr. | Feb 1999 | A |
6089667 | Hobbs | Jul 2000 | A |
Number | Date | Country |
---|---|---|
0 836 821 | Apr 1998 | EP |
2098060 | Nov 1982 | GB |
Number | Date | Country | |
---|---|---|---|
20040232739 A1 | Nov 2004 | US |
Number | Date | Country | |
---|---|---|---|
60300315 | Jun 2001 | US |