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Ergonomics - Spinal column
- 2. Relation to Ergonomics Prevention Of Risk Factors Structure & Function Risk Factors
- 4. vertebrae vertebrae vertebrae Fused vertebrae Fused vertebrae
- 5. S-Curved
- 6. Spinal Disc
- 7. Supports the weight of the body parts above them
- 8. Transmit the load to the legs via the hip joints.
- 10. Relation to Ergonomics study of the relation between people and their work environment. Used to prevent injuries and illnesses associated with the design of physical work. Science of fitting the work to the user instead of forcing the user to fit the work. Used to increase employee safety and comfort and to optimize work performance and quality
- 13. Causes of Back Pain
- 14. Causes of Back Pain
- 15. Causes of Back Pain
- 16. Causes of Back Pain
- 18. Relation to Ergonomics study of the relation between people and their work environment. Used to prevent injuries and illnesses associated with the design of physical work. Science of fitting the work to the user instead of forcing the user to fit the work. Used to increase employee safety and comfort and to optimize work performance and quality
- 20. Lifting
- 21. Lifting
- 23. is better than pulling Lets you use larger muscles with less strain on the back Less likely to slip
Editor's Notes
- Your sacrum (from the Medieval Latin os sacrum, meaning holy bone), the flat triangular bone situated between your hips, is actually five fused vertebrae. This fusion isn't complete until you're about 25 or 30. This part is the lowest and last curve in your spine. The curve, called the lumbosacral curve, helps support body weight. Below the sacrum is the tail end of your spine, called the coccyx or tailbone. Again, several fused vertebrae (generally 3–5) form the coccyx. he cervical region (neck) the thoracic region (chest) the lumbar region (lower back) & the sacral region (pelvic)
- THERE ARE TWO FORWARD BENDS IN CERVICAL AND LUMBAR AND ONE BACKWARD BEND ON THE CHEST AREA
- Discs are actually composed of two parts: a tough outer portion and a soft inner core, and the configuration has been likened to that of a jelly doughnut (see a healthy disc with Figure 1). The outer portion of the disc (annulus fibrosus) is the tough circular exterior composed of concentric sheets of collagen fibers (lamellae) that surround the inner core. The inner core (nucleus pulposus) contains a loose network of fibers suspended in a mucoprotein gel.
- The Spine and pelvis support the weight of the body parts above them and transmit the load to the legs via the hip joints. They are also involved in movement. Almost all movements of the torso and head involve the spine and pelvis in varying degree. As Spine Connects
- and transmit the load to the legs via the hip joints. They are also involved in movement. Almost all movements of the torso and head involve the spine and pelvis in varying degree. As Spine Connects
- As Spine is connected to such organs, improper posture of the spine through the years may lead to some complications or Strains such as Lower Back Pain, And where could improper posture be developed from? Why does it occur? Well it is ofcourse due to the products we use everyday, like the chair due to its unmatched design, that’s why IES do their or our best to develop a design that would lessen the strain to the worker especially when it performs a repetitive task. Prevention is by far the treatment of choice. Improved muscle function can be preventative. Poor coordination and motor control systems are as important as endurance and strength. Fixed postures should be avoided. Seats offering good lumbar support should be used in the office For, if there would be less strain or fatigue it would be equal to a Comfortability and Satisfaction of the Worker, where ergonomics is all about.
- study of the relation between people and their work environment. 3. Used to prevent injuries and illnesses associated with the design of physical work. 4. Science of fitting the work to the user instead of forcing the user to fit the work. 5. Used to increase employee safety and comfort and to optimize work performance and quality
- Risk factors for musculoskeletal disorders in the workplace The main risk factors for musculoskeletal disorders can be categorised under one of four headings: • Force • Posture • Repetition • Duration of task spine. It is probable that proprioception deficits are associated with LBP and low back injuries. Proprioception decreases with aging, with lack of exercise, and in those with LBP. A system with feedback has been successfully used to rehabilitate those with chronic LBP.With prolonged exposure to lifting or excessive postures such as full flexion, the viscoelastic structures of the lumbar spine will become stretched out due to creep. Gedalia et al. (17) reported that laxity in the viscoelastic structures desensitizes the mechano-receptors within and causes loss of reflexive stabilizing forces from the multifidus muscles. The first 10 minutes of rest after cyclic loading results in fast partial recovery of muscular activity; full recovery is not possible even with rest periods twice as long as the loading period. Thismayincrease the risk of instability, injury, and pain in the spine.
- Causes of low back pain Low back and shoulder girdle pain are major problems in the industrialised world. Frequently, the pain is of an acute form and is due to muscular fatigue. This type of pain usually subsides within hours or days if the sufferer rests. However, for some individuals the pain is chronic and may be indicative of an underlying pathology. In these cases, it may be difficult to construct a complete causal explanation and medical advice may be required. Similar reasoning rules out pain from the capsules of the apophyseal joints. Apophyseal joints are hinge-like joints that allow the flexion, extension and torsion of the spine. These joints also interlock the vertebra to make the spine more stable. Likely sources of pain are the posterior ligaments and the back muscles. These may be irritated by mechanical trauma due to damage to or degeneration of bony structures, or the pain may be due to fatigue. Nerve root compression can also be a source of pain. Pain from the sacroiliac joint can sometimes be mistaken for low back pain (DonTigny, 1985) and evidence is accumulating that the sacroiliac joint is the source of pain below L5–S1 (Schwarzer et al., 1995). Back pain can occur for non-work-related reasons and from unrelated structures such as the kidneys. Colds and flu may cause complaints of pain in the back. Back pain is a complex problem (Waddell, 1982) and detailed investigation of back problems is best left to expert clinicians. If a worker complains of back pain, the ergonomist’s natural inclination is to search for causes in the workplace. In the case of strenuous jobs, this may be appropriate but, in less obvious cases, nonoccupational and potentially more serious causes should also be considered.
- Causes of low back pain Although the anatomy of the spine is well understood, finding the source and cause of low back pain can be a much more elusive problem for clinicians. Pain is unlikely to arise from the intervertebral discs themselves since only the outer parts contain nerve endings in the adult. Similar reasoning rules out pain from the capsules of the apophyseal joints. Apophyseal joints are hinge-like joints that allow the flexion, extension and torsion of the spine. These joints also interlock the vertebra to make the spine more stable. Likely sources of pain are the posterior ligaments and the back muscles. These may be irritated by mechanical trauma due to damage to or degeneration of bony structures, or the pain may be due to fatigue. Nerve root compression can also be a source of pain. Pain from the sacroiliac joint can sometimes be mistaken for low back pain (DonTigny, 1985) and evidence is accumulating that the sacroiliac joint is the source of pain below L5–S1 (Schwarzer et al., 1995). Back pain can occur for non-work-related reasons and from unrelated structures such as the kidneys. Colds and flu may cause complaints of pain in the back. Back pain is a complex problem (Waddell, 1982) and detailed investigation of back problems is best left to expert clinicians. If a worker complains of back pain, the ergonomist’s natural inclination is to search for causes in the workplace. In the case of strenuous jobs, this may be appropriate but, in less obvious cases, nonoccupational and potentially more serious causes should also be considered.
- Causes of low back pain Although the anatomy of the spine is well understood, finding the source and cause of low back pain can be a much more elusive problem for clinicians. Pain is unlikely to arise from the intervertebral discs themselves since only the outer parts contain nerve endings in the adult. Similar reasoning rules out pain from the capsules of the apophyseal joints. Apophyseal joints are hinge-like joints that allow the flexion, extension and torsion of the spine. These joints also interlock the vertebra to make the spine more stable. Likely sources of pain are the posterior ligaments and the back muscles. These may be irritated by mechanical trauma due to damage to or degeneration of bony structures, or the pain may be due to fatigue. Nerve root compression can also be a source of pain. Pain from the sacroiliac joint can sometimes be mistaken for low back pain (DonTigny, 1985) and evidence is accumulating that the sacroiliac joint is the source of pain below L5–S1 (Schwarzer et al., 1995). Back pain can occur for non-work-related reasons and from unrelated structures such as the kidneys. Colds and flu may cause complaints of pain in the back. Back pain is a complex problem (Waddell, 1982) and detailed investigation of back problems is best left to expert clinicians. If a worker complains of back pain, the ergonomist’s natural inclination is to search for causes in the workplace. In the case of strenuous jobs, this may be appropriate but, in less obvious cases, nonoccupational and potentially more serious causes should also be considered.
- Causes of low back pain Although the anatomy of the spine is well understood, finding the source and cause of low back pain can be a much more elusive problem for clinicians. Pain is unlikely to arise from the intervertebral discs themselves since only the outer parts contain nerve endings in the adult. Similar reasoning rules out pain from the capsules of the apophyseal joints. Apophyseal joints are hinge-like joints that allow the flexion, extension and torsion of the spine. These joints also interlock the vertebra to make the spine more stable. Likely sources of pain are the posterior ligaments and the back muscles. These may be irritated by mechanical trauma due to damage to or degeneration of bony structures, or the pain may be due to fatigue. Nerve root compression can also be a source of pain. Pain from the sacroiliac joint can sometimes be mistaken for low back pain (DonTigny, 1985) and evidence is accumulating that the sacroiliac joint is the source of pain below L5–S1 (Schwarzer et al., 1995). Back pain can occur for non-work-related reasons and from unrelated structures such as the kidneys. Colds and flu may cause complaints of pain in the back. Back pain is a complex problem (Waddell, 1982) and detailed investigation of back problems is best left to expert clinicians. If a worker complains of back pain, the ergonomist’s natural inclination is to search for causes in the workplace. In the case of strenuous jobs, this may be appropriate but, in less obvious cases, nonoccupational and potentially more serious causes should also be considered.
- Causes of low back pain Although the anatomy of the spine is well understood, finding the source and cause of low back pain can be a much more elusive problem for clinicians. Pain is unlikely to arise from the intervertebral discs themselves since only the outer parts contain nerve endings in the adult. Similar reasoning rules out pain from the capsules of the apophyseal joints. Apophyseal joints are hinge-like joints that allow the flexion, extension and torsion of the spine. These joints also interlock the vertebra to make the spine more stable. Likely sources of pain are the posterior ligaments and the back muscles. These may be irritated by mechanical trauma due to damage to or degeneration of bony structures, or the pain may be due to fatigue. Nerve root compression can also be a source of pain. Pain from the sacroiliac joint can sometimes be mistaken for low back pain (DonTigny, 1985) and evidence is accumulating that the sacroiliac joint is the source of pain below L5–S1 (Schwarzer et al., 1995). Back pain can occur for non-work-related reasons and from unrelated structures such as the kidneys. Colds and flu may cause complaints of pain in the back. Back pain is a complex problem (Waddell, 1982) and detailed investigation of back problems is best left to expert clinicians. If a worker complains of back pain, the ergonomist’s natural inclination is to search for causes in the workplace. In the case of strenuous jobs, this may be appropriate but, in less obvious cases, nonoccupational and potentially more serious causes should also be considered.
- Causes of low back pain Although the anatomy of the spine is well understood, finding the source and cause of low back pain can be a much more elusive problem for clinicians. Pain is unlikely to arise from the intervertebral discs themselves since only the outer parts contain nerve endings in the adult. Similar reasoning rules out pain from the capsules of the apophyseal joints. Apophyseal joints are hinge-like joints that allow the flexion, extension and torsion of the spine. These joints also interlock the vertebra to make the spine more stable. Likely sources of pain are the posterior ligaments and the back muscles. These may be irritated by mechanical trauma due to damage to or degeneration of bony structures, or the pain may be due to fatigue. Nerve root compression can also be a source of pain. Pain from the sacroiliac joint can sometimes be mistaken for low back pain (DonTigny, 1985) and evidence is accumulating that the sacroiliac joint is the source of pain below L5–S1 (Schwarzer et al., 1995). Back pain can occur for non-work-related reasons and from unrelated structures such as the kidneys. Colds and flu may cause complaints of pain in the back. Back pain is a complex problem (Waddell, 1982) and detailed investigation of back problems is best left to expert clinicians. If a worker complains of back pain, the ergonomist’s natural inclination is to search for causes in the workplace. In the case of strenuous jobs, this may be appropriate but, in less obvious cases, nonoccupational and potentially more serious causes should also be considered.
- study of the relation between people and their work environment. 3. Used to prevent injuries and illnesses associated with the design of physical work. 4. Science of fitting the work to the user instead of forcing the user to fit the work. 5. Used to increase employee safety and comfort and to optimize work performance and quality
- Lifting LBP is associated with lifting, but instructions for the “proper” technique have been controversial. The principle is to hold the object as close to the body as possible, which is more important than keeping a straight back (18). Brinckmann et al. (19) reported that spinal loading during forward bent posture results in a height decrease or deformation of lumbar vertebrae. Other things affect the way we lift. Chen (20) showed that when muscle fatigue occurs in the arms, the lifting strategy becomes more stressful on the back, and whole-body lifting should be avoided in order to reduce the risk of injury to the lower back. The worker should use smooth lifting technique without jerking to minimize the effect of dynamic loads on the spine. Asymmetric lifting is associated with an increased risk of lowback disorders according to Kingma et al. (23); small deviations of a lifting movement from the sagittal plane can increase risk of low back disorders. Antagonistic cocontraction affects spinal stability and spinal compression. For antagonistic cocontraction to be beneficial, stability must increase more than spinal load. Antagonistic cocontraction is beneficial at low trunk moments typically observed in upright postures (24). Granata et al. (25) found that weight, task asymmetry, and job experience (level of experience) affect the magnitude and variability of spinal load during repeated lifting exertions. Gagnon & Smith (26) also point out that slower lifts with reduced acceleration when lifting moderately heavywork may present less of a risk to lowback disorder. With regard to our aging workforce, bending and lifting activities generate loads on the spine that exceed the failure load of vertebrae with lowbone mineral density. This yields a high factor of risk (ratio of load on spine to failure load of bone) (27). In critical tasks with twisting, it is important to have the worker turning with the feet to reduce the torsional loads on the intervertebral discs. The relative merits of back-stooped posture versus knee lifts are debated. However, lifting a bulky load with an erect back increases the intradiscal pressure (IDP) compared to the backstooped posture because of the increased moment arm and the vertical component of body weight and hand forces. However, shear forces are greater when lifting with the back flexed and the articular capsule and the posterior ligaments may be overstrained. Workers may lift loads with their backs rather than their legs to maximize the available energy. IDP is similar with back lift and leg lift if the load moment arm is constant. Intra-abdominal pressure (IAP) has been proposed as a major source of column support.
- Causes of low back pain Although the anatomy of the spine is well understood, finding the source and cause of low back pain can be a much more elusive problem for clinicians. Pain is unlikely to arise from the intervertebral discs themselves since only the outer parts contain nerve endings in the adult. Similar reasoning rules out pain from the capsules of the apophyseal joints. Apophyseal joints are hinge-like joints that allow the flexion, extension and torsion of the spine. These joints also interlock the vertebra to make the spine more stable. Likely sources of pain are the posterior ligaments and the back muscles. These may be irritated by mechanical trauma due to damage to or degeneration of bony structures, or the pain may be due to fatigue. Nerve root compression can also be a source of pain. Pain from the sacroiliac joint can sometimes be mistaken for low back pain (DonTigny, 1985) and evidence is accumulating that the sacroiliac joint is the source of pain below L5–S1 (Schwarzer et al., 1995). Back pain can occur for non-work-related reasons and from unrelated structures such as the kidneys. Colds and flu may cause complaints of pain in the back. Back pain is a complex problem (Waddell, 1982) and detailed investigation of back problems is best left to expert clinicians. If a worker complains of back pain, the ergonomist’s natural inclination is to search for causes in the workplace. In the case of strenuous jobs, this may be appropriate but, in less obvious cases, nonoccupational and potentially more serious causes should also be considered.
- Causes of low back pain Although the anatomy of the spine is well understood, finding the source and cause of low back pain can be a much more elusive problem for clinicians. Pain is unlikely to arise from the intervertebral discs themselves since only the outer parts contain nerve endings in the adult. Similar reasoning rules out pain from the capsules of the apophyseal joints. Apophyseal joints are hinge-like joints that allow the flexion, extension and torsion of the spine. These joints also interlock the vertebra to make the spine more stable. Likely sources of pain are the posterior ligaments and the back muscles. These may be irritated by mechanical trauma due to damage to or degeneration of bony structures, or the pain may be due to fatigue. Nerve root compression can also be a source of pain. Pain from the sacroiliac joint can sometimes be mistaken for low back pain (DonTigny, 1985) and evidence is accumulating that the sacroiliac joint is the source of pain below L5–S1 (Schwarzer et al., 1995). Back pain can occur for non-work-related reasons and from unrelated structures such as the kidneys. Colds and flu may cause complaints of pain in the back. Back pain is a complex problem (Waddell, 1982) and detailed investigation of back problems is best left to expert clinicians. If a worker complains of back pain, the ergonomist’s natural inclination is to search for causes in the workplace. In the case of strenuous jobs, this may be appropriate but, in less obvious cases, nonoccupational and potentially more serious causes should also be considered.
- Pulling pushing Ayoub & McDaniel (33) found that body posture plays an important role in the force capability in both pushing and pulling and is probably very important in the etiology of pulling or pushing LBP injuries. Friedrich et al. (34) found that combined walking and pushing under vertical space constraints was associated with increased lumbar flexion and thoracic extension. The latter increasewas due to an attempt to enhance abdominal muscle strength. The health care professions are at a high risk ofLBP, and pushing-pulling activities are no exception. Lavender et al. (35) found the most hazardous tasks performed by emergency medical technicians included pulling a victim from a bed to a stretcher, the initial descent of a set of stairs when using the stretcher, and lifting a victim on a backboard from the floor.
- Posture The posture at work can cause LBP. We have already mentioned the antagonistic muscle activity and the effect on spinal loading. McGill et al. (36) pointed out that anterior shear load on the lumbar spine increases the risk of LBP. Bending forward allows the spine to fully flex; this changes the line of action of the largest extensor muscles and reduces their effectiveness to support anterior shear forces. In fact, in this position, the muscles become inactive and the person is hanging by their soft tissues. McGill et al. (36) found that fully flexing the spine renders the lumbar extensor muscles ineffective for supporting anterior shear forces. Anterior shear load on the lumbar spine is highly related to the risk of back injury. Jobs such as seated warehouse shipper, gardener, and construction worker require such postures. Potvin et al. (37) also pointed out that during lifting, the risk of injury to the spine may be increased more by the degree of lumbar flexion than the choice of stoop or squat technique. McGill & Brown (38) measured creep response of the lumbar spine from nine min of full flexion posture. Full recovery took »30 min. Many workers have to work in extreme postures. Gallagher et al. (39) found that the effect of the kneeling posture, used in construction and mining, is increased
- Although the aetiology of musculoskeletal problems involves several factors, it is known that pain can be caused or exacerbated by excessive loading of joints and muscles. This can occur not only as a result of traumatic events but also owing to sustained exposure to particular working postures. Nachemson (1966) used a needle transducer to measure the hydrostatic pressure in the third lumbar intervertebral disc. Disc pressure was found to be higher in sitting than in lying down but was reduced when the sitter reclined against a backrest. Other researchers (e.g. Adams and Hutton, 1985; Andersson, 1986; Keegan, 1953; Schierhout et al., 1992) have also presented data that support the notion that it is not whether we stand or sit that causes undue postural stress but how. Can low back pain be prevented? Case studies demonstrating the effectiveness of specific ergonomic interventions are given in later chapters. In general, the evidence that low back pain can be prevented in the general population is not promising, as is evident in the following review papers. Linton and van Tulder (2001) reviewed controlled trials of prevention programmes and found that exercise had a mild protective effect. Van Tulder et al. (2000) found that exercise was ineffective as a form of therapy for acute low back pain but that there was some evidence that it was effective as therapy for chronic low back pain in facilitating the return to normal daily activities, including work. On balance, there seems to be some evidence that exercise is beneficial, particularly if it strengthens the trunk or improves endurance of the trunk muscles. The mechanisms by which exercise may help are unknown. It is of interest that Stevenson et al. (2001) found that personal fitness is an important defence against low back pain. Their prospective study of manual workers handling more than 5000 kg/day showed that those who did not get back problems had stronger static leg strength and endurance and could move their upper bodies faster than those who went on to develop problems.
- Although the aetiology of musculoskeletal problems involves several factors, it is known that pain can be caused or exacerbated by excessive loading of joints and muscles. This can occur not only as a result of traumatic events but also owing to sustained exposure to particular working postures. Nachemson (1966) used a needle transducer to measure the hydrostatic pressure in the third lumbar intervertebral disc. Disc pressure was found to be higher in sitting than in lying down but was reduced when the sitter reclined against a backrest. Other researchers (e.g. Adams and Hutton, 1985; Andersson, 1986; Keegan, 1953; Schierhout et al., 1992) have also presented data that support the notion that it is not whether we stand or sit that causes undue postural stress but how. Can low back pain be prevented? Case studies demonstrating the effectiveness of specific ergonomic interventions are given in later chapters. In general, the evidence that low back pain can be prevented in the general population is not promising, as is evident in the following review papers. Linton and van Tulder (2001) reviewed controlled trials of prevention programmes and found that exercise had a mild protective effect. Van Tulder et al. (2000) found that exercise was ineffective as a form of therapy for acute low back pain but that there was some evidence that it was effective as therapy for chronic low back pain in facilitating the return to normal daily activities, including work. On balance, there seems to be some evidence that exercise is beneficial, particularly if it strengthens the trunk or improves endurance of the trunk muscles. The mechanisms by which exercise may help are unknown. It is of interest that Stevenson et al. (2001) found that personal fitness is an important defence against low back pain. Their prospective study of manual workers handling more than 5000 kg/day showed that those who did not get back problems had stronger static leg strength and endurance and could move their upper bodies faster than those who went on to develop problems.
- Although the aetiology of musculoskeletal problems involves several factors, it is known that pain can be caused or exacerbated by excessive loading of joints and muscles. This can occur not only as a result of traumatic events but also owing to sustained exposure to particular working postures. Nachemson (1966) used a needle transducer to measure the hydrostatic pressure in the third lumbar intervertebral disc. Disc pressure was found to be higher in sitting than in lying down but was reduced when the sitter reclined against a backrest. Other researchers (e.g. Adams and Hutton, 1985; Andersson, 1986; Keegan, 1953; Schierhout et al., 1992) have also presented data that support the notion that it is not whether we stand or sit that causes undue postural stress but how. Can low back pain be prevented? Case studies demonstrating the effectiveness of specific ergonomic interventions are given in later chapters. In general, the evidence that low back pain can be prevented in the general population is not promising, as is evident in the following review papers. Linton and van Tulder (2001) reviewed controlled trials of prevention programmes and found that exercise had a mild protective effect. Van Tulder et al. (2000) found that exercise was ineffective as a form of therapy for acute low back pain but that there was some evidence that it was effective as therapy for chronic low back pain in facilitating the return to normal daily activities, including work. On balance, there seems to be some evidence that exercise is beneficial, particularly if it strengthens the trunk or improves endurance of the trunk muscles. The mechanisms by which exercise may help are unknown. It is of interest that Stevenson et al. (2001) found that personal fitness is an important defence against low back pain. Their prospective study of manual workers handling more than 5000 kg/day showed that those who did not get back problems had stronger static leg strength and endurance and could move their upper bodies faster than those who went on to develop problems.
- Although the aetiology of musculoskeletal problems involves several factors, it is known that pain can be caused or exacerbated by excessive loading of joints and muscles. This can occur not only as a result of traumatic events but also owing to sustained exposure to particular working postures. Nachemson (1966) used a needle transducer to measure the hydrostatic pressure in the third lumbar intervertebral disc. Disc pressure was found to be higher in sitting than in lying down but was reduced when the sitter reclined against a backrest. Other researchers (e.g. Adams and Hutton, 1985; Andersson, 1986; Keegan, 1953; Schierhout et al., 1992) have also presented data that support the notion that it is not whether we stand or sit that causes undue postural stress but how. Can low back pain be prevented? Case studies demonstrating the effectiveness of specific ergonomic interventions are given in later chapters. In general, the evidence that low back pain can be prevented in the general population is not promising, as is evident in the following review papers. Linton and van Tulder (2001) reviewed controlled trials of prevention programmes and found that exercise had a mild protective effect. Van Tulder et al. (2000) found that exercise was ineffective as a form of therapy for acute low back pain but that there was some evidence that it was effective as therapy for chronic low back pain in facilitating the return to normal daily activities, including work. On balance, there seems to be some evidence that exercise is beneficial, particularly if it strengthens the trunk or improves endurance of the trunk muscles. The mechanisms by which exercise may help are unknown. It is of interest that Stevenson et al. (2001) found that personal fitness is an important defence against low back pain. Their prospective study of manual workers handling more than 5000 kg/day showed that those who did not get back problems had stronger static leg strength and endurance and could move their upper bodies faster than those who went on to develop problems.