Gunnar B. Andersson

Bio: Gunnar B. Andersson is an academic researcher from Rush University Medical Center. The author has contributed to research in topics: Low back pain & Back pain. The author has an hindex of 45, co-authored 97 publications receiving 11234 citations. Previous affiliations of Gunnar B. Andersson include University of Michigan.

A Study of Lower-Limb Mechanics During Stair-Climbing

Abstract: The motions, forces, and moments at the major joints of the lower limbs of ten men ascending and descending stairs were analyzed using an optoelectronic system, a force-plate, and electromyography. The mean values for the maximum sagittalplane motions of the hip, knee, and ankle were 42, 88, and 27 degrees, respectively. The mean maximum net flexion-extension moments were: at the hip, 123.9 newton-meters going up and 112.5 newton-meters going down stairs; at the knee, 57.1 newton-meters going up and 146.6 newton-meters going down stairs; and at the ankle, 137.2 newton-meters going up and 107.5 newton-meters going down stairs. When going up and down stairs large moments are present about weight-bearing joints, but descending movements produce the largest moments. The magnitudes of these moments are considerably higher than those produced during level walking.

A novel rabbit model of mild, reproducible disc degeneration by an anulus needle puncture: correlation between the degree of disc injury and radiological and histological appearances of disc degeneration.

Abstract: Study design An in vivo study to radiographically and histologically assess a new method of induction of disc degeneration. OBJECTIVE.: To establish a reproducible rabbit model of disc degeneration by puncturing the anulus with needles of defined gauges and to compare it to the classic stab model. Summary of background data New treatment approaches to disc degeneration are of great interest. Although animal models for disc degenerative disease exist, the quantitative measurement of disease progression remains difficult. A reproducible, progressive disc degeneration model, which can be induced in a reasonable time frame, is essential for development of new therapeutic interventions. Methods The classic anular stab model and the new needle puncture model were used in the rabbit. For the needle puncture model, 3 different gauges of needle (16G, 18G, and 21G) were used to induce an injury to the disc to a depth of 5 mm. Radiographic and histologic analyses were performed; magnetic resonance images were also assessed in the needle puncture model. Results Significant disc space narrowing was observed as early as 2 weeks after stabbing in the classic stab model; there was no further narrowing of the disc space. In the needle puncture model, all needle sizes tested induced a slower and more progressive decrease in disc height than in the classic stab model. The magnetic resonance imaging supported the results of disc height data. Conclusions The needle puncture approach, using 16G to 21G needles, resulted in a reproducible decrease of disc height and magnetic resonance imaging grade. The ease of the procedure and transfer of the methodology will benefit researchers studying disc degeneration.

Epidemiologic aspects on low-back pain in industry.

Abstract: The role of epidemiology with respect to back pain in industry is to clarify the natural history and clinical course of the pain and to identify workplace factors and individual factors of importance. On the basis of knowledge obtained through epidemiologic research, preventive measures can be instituted and risk factors eliminated. This paper reviews epidemiological data accumulated over the past 30 years. The impact of back conditions on industry is emphasized.

Prevalence of back pain in pregnancy.

Abstract: The prevalence of back pain was studied in 855 pregnant women who were followed from the 12th week of pregnancy, every 2nd week, until childbirth. The 9-month period prevalence was 49%, with a point prevalence of 22-28% from the 12th week until delivery. Because 22% of the women had back pain at the

Burden of major musculoskeletal conditions

Abstract: Musculoskeletal conditions are a major burden on individuals, health systems, and social care systems, with indirect costs being predominant. This burden has been recognized by the United Nations and WHO, by endorsing the Bone and Joint Decade 2000-2010. This paper describes the burden of four major musculoskeletal conditions: osteoarthritis, rheumatoid arthritis, osteoporosis, and low back pain. Osteoarthritis, which is characterized by loss of joint cartilage that leads to pain and loss of function primarily in the knees and hips, affects 9.6% of men and 18% of women aged > 60 years. Increases in life expectancy and ageing populations are expected to make osteoarthritis the fourth leading cause of disability by the year 2020. Joint replacement surgery, where available, provides effective relief. Rheumatoid arthritis is an inflammatory condition that usually affects multiple joints. It affects 0.3-1.0% of the general population and is more prevalent among women and in developed countries. Persistent inflammation leads to joint destruction, but the disease can be controlled with drugs. The incidence may be on the decline, but the increase in the number of older people in some regions makes it difficult to estimate future prevalence. Osteoporosis, which is characterized by low bone mass and microarchitectural deterioration, is a major risk factor for fractures of the hip, vertebrae, and distal forearm. Hip fracture is the most detrimental fracture, being associated with 20% mortality and 50% permanent loss in function. Low back pain is the most prevalent of musculoskeletal conditions; it affects nearly everyone at some point in time and about 4-33% of the population at any given point. Cultural factors greatly influence the prevalence and prognosis of low back pain.

Diagnosis and Treatment of Low Back Pain: A Joint Clinical Practice Guideline from the American College of Physicians and the American Pain Society

Abstract: Recommendation 1: Clinicians should conduct a focused history and physical examination to help place patients with low back pain into 1 of 3 broad categories: nonspecific low back pain, back pain potentially associated with radiculopathy or spinal stenosis, or back pain potentially associated with another specific spinal cause. The history should include assessment of psychosocial risk factors, which predict risk for chronic disabling back pain (strong recommendation, moderate-quality evidence). Recommendation 2: Clinicians should not routinely obtain imaging or other diagnostic tests in patients with nonspecific low back pain (strong recommendation, moderate-quality evidence). Recommendation 3: Clinicians should perform diagnostic imaging and testing for patients with low back pain when severe or progressive neurologic deficits are present or when serious underlying conditions are suspected on the basis of history and physical examination (strong recommendation, moderate-quality evidence). Recommendation 4: Clinicians should evaluate patients with persistent low back pain and signs or symptoms of radiculopathy or spinal stenosis with magnetic resonance imaging (preferred) or computed tomography only if they are potential candidates for surgery or epidural steroid injection (for suspected radiculopathy) (strong recommendation, moderate-quality evidence). Recommendation 5: Clinicians should provide patients with evidence-based information on low back pain with regard to their expected course, advise patients to remain active, and provide information about effective self-care options (strong recommendation, moderate-quality evidence). Recommendation 6: For patients with low back pain, clinicians should consider the use of medications with proven benefits in conjunction with back care information and self-care. Clinicians should assess severity of baseline pain and functional deficits, potential benefits, risks, and relative lack of long-term efficacy and safety data before initiating therapy (strong recommendation, moderate-quality evidence). For most patients, first-line medication options are acetaminophen or nonsteroidal anti-inflammatory drugs. Recommendation 7: For patients who do not improve with selfcare options, clinicians should consider the addition of nonpharmacologic therapy with proven benefits—for acute low back pain, spinal manipulation; for chronic or subacute low back pain, intensive interdisciplinary rehabilitation, exercise therapy, acupuncture, massage therapy, spinal manipulation, yoga, cognitive-behavioral therapy, or progressive relaxation (weak recommendation, moderate-quality evidence).