Research Review By Gary J. Maguire©

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Date Posted:

January 2011

Study Title:

Age-Related Hyperkyphosis: Its Causes, Consequences, and Management

Authors:

W Katzman et al.

Author's Affiliations:

Department of Physical Therapy and Rehabilitation Science, University of California, San Francisco, San Francisco, CA, USA

Publication Information:

Journal of Orthopaedic & Sports Physical Therapy 2010; 40; 352-360.

Background Information:

Age-related postural hyperkyphosis presents as an exaggerated anterior curvature of the thoracic spine. Often referred to as a Dowager’s hump or gibbous deformity, this condition impairs mobility and is thought to increase the risk of falls or fractures. Associated muscle weakness or degenerative disc disease may lead to vertebral compression fractures and worsening of this condition. Vertebral compression fractures may also precipitate the development of this deformity.

Formally, hyperkyphosis is defined as a thoracic kyphosis angle greater than 40° (which is the 95th percentile for normal young adults). From childhood through the third decade of life the angle averages 20 to 29 degrees. Typically, this kyphotic angle begins to progress after 40 years of age (more rapidly in women than men) to an average of ~52° in women 76 to 80 years of age. The prevalence and incidence of hyperkyphosis in older adults vary from approximately 20 to 40 percent among men and women. Physical capacity and quality of life often declines as the angle increases, which has lead to the need for early recognition strategies and intervention programs.

Pertinent Results:

Standing lateral spine radiographs continue to be the gold-standard diagnostic technique for assessment of thoracic kyphosis. Spinal radiographs taken in a supine position are also acceptable as this can improve comfort in the elderly. Kyphosis is usually calculated using the Cobb angle (lines drawn perpendicular to the superior endplate at the top of the curve region [usually around T4] and inferior endplate of the bottom vertebra in the curve region [variable but normally ~T12] are intersected and that angle is measured on a standard lateral thoracic radiograph).

Two alternatives to radiographic measurements are the Debrunner kyphometer and the flexicurve ruler, both of which are used in a standing position. Although both use different methods of measuring kyphosis, intrarater and interrater reliability are excellent (1). One limitation is that the kyphometer may overestimate the degree of kyphosis when compared to supine radiographs. However, using devices like these can minimize radiographic exposure, and they are relatively easy to use as well as cost effective.

Findings:
  • Functional Limitations: Physical performance, functional ADLs and quality of life diminish with excessive kyphosis. Hyperkyphotic posture often creates difficulty with rising from a chair without the use of the arms, diminishes balance and is associated with reduced gait velocity. Patients utilize a wider base of support in stance and gait as well as exhibiting decreased stair-climbing speed. These alterations have all been associated with increased risk of falling. Women with hyperkyphosis often score lower on basic ADL scales and report a greater difficulty with reaching and performing heavy housework.
  • Musculoskeletal Alterations: With an increase in kyphosis there are concomitant alterations in the normal sagittal plane alignment. This may cause pain and increase the risk of dysfunction in the shoulders, pelvis and other spinal areas. Forward head posture, scapular protraction, reduced lumbar lordosis and decreased standing height often occur with hyperkyphosis. These changes lead to an increase flexion bias around the hip and shoulder joints creating alterations in normal joint mechanics and functional movement. There is also a 70% increased risk of future fracture in older women, independent of age or prior fracture (2). This risk of fracture increases as hyperkyphosis progresses.
  • Quality of Life: Men and women 65 years and older with hyperkyphosis report poorer satisfaction with subjective health, family relationships, economic conditions and their lives in general. Women especially report physical difficulty, increased adaptations to their lives and greater generalized fears.
  • Mortality: Hyperkyphotic posture is associated with increased mortality based on curve severity. Reduced vital capacity and pulmonary death are also linked to hyperkyphosis.
  • Vertebral Fractures: Kyphosis itself increases with the number of vertebral compression fractures – this is of course more directly related to thoracic fractures than lumbar fractures. These fractures occur because of increased stress and loading on the vertebrae that are osteoporotic and not strong enough structurally to withstand this force…vertebral wedging and subsequent fractures result.
  • Degenerative Disc Disease: There is evidence that degenerative disc disease contributes to hyperkyphosis with a significant correlation between anterior disc height and kyphosis angle; as the anterior disc height decreased, the angle of kyphosis increased. The influence of both degenerative disc disease and anterior vertebral deformities accounts for significant variation in kyphosis severity.
  • Muscle Weakness: Evidence suggests that hyperkyphosis is associated with spinal extensor muscle weakness. In postmenopausal women, it has been demonstrated that the strength of spinal extensor muscles is inversely associated with kyphosis. There is also evidence to support an inverse relationship between grip and ankle strength and kyphosis. This suggests that age-related hyperkyphosis may be part of a larger geriatric syndrome associated with adverse health outcomes that negatively impact physical function.
  • Decreased Mobility: Spinal extension decreases with aging which limits functional mobility. Cadaver studies suggest that calcification and ossification of the anterior longitudinal ligament in the thoracic region might contribute to an increased Cobb’s angle of kyphosis. There is also a relationship between shorter pectoral and hip flexor muscles with hyperkyphosis. It is not known though if the short muscles pull the shoulders and hips anteriorly or whether the kyphotic posture leads to shorter anterior musculature.
  • Sensory Deficits: The loss of proprioceptive and vibratory input from the joints in the lower extremities in elderly adults compared with young adults causes erect vertical alignment to become impaired. Age-related sensory loss in the vestibular system increases reliance on already declining visual and somatosensory cues, further impacting upright postural alignment.

Clinical Application & Conclusions:

Studies support that exercise, bracing and taping interventions help reduce hyperkyphosis and the risk of future fractures. The authors suggest that physical therapy should be the first line of approach because many of the causes of hyperkyphosis are of musculoskeletal origin.

Although individuals with osteoporosis are treated with antiresorptive or bone-building medications to prevent incident spine fractures, no medications have been shown to improve hyperkyphosis. Evidence suggests that physical disability and pain relief may be improved after vertebroplasty and kyphoplasty when compared to medical management (only within the first 3 months after intervention).

Research suggests that forces applied to the spine during exercise can alter the occurrence of subsequent vertebral compression fractures in women with prior fractures. It is important to train individuals with age-related hyperkyphosis to avoid flexion stresses on the spine during exercise or ADLs (regardless if they have had a previous fracture). Individuals should also avoid curl-up and other flexion-dominant exercises to reduce flexion stresses on the thoracic segments.

There continues to be emerging evidence that targeted exercises (primarily extension-based) that reduce hyperkyphosis provide long-term benefits. The combination of respiratory muscle exercises, aerobic training and back extensor exercises in a study of 14 women produced results of improved respiratory pressures of 12% to 23%, increased exercise tolerance of 13% and reduced thoracic curvature of 5%.

Although manual medicine providers anecdotally report that myofascial, spinal and scapular mobilization techniques combined with exercise can improve postural alignment in patients with hyperkyphosis, there has not been rigorous evaluation in clinical trials that can help guide our clinical approach. The use of self-mobilization lying on a foam roller has been used successfully in a multidimensional exercise program that reduced kyphosis in women (3).

Bracing and taping also provide some benefit in the reduction of hyperkyphosis. In a study that evaluated the effect of wearing a Spinomed spinal orthosis 2 hours/day for 6 months, an 11% decrease in the kyphosis angle, improved standing height, increased extensor strength and decreased postural sway were noted. However, spinal bracing does not provide the benefits of exercise on bone. Other braces such as the spinal weighted kyphosis orthosis has also been shown to improve balance and reduce pain. Therapeutic taping also may be beneficial in reducing kyphosis angle according some recent research (see Related Reviews below).

Screening for hyperkyphosis in a clinical setting could help prevent serious associated complications of impaired physical performance, health and quality of life. Evidence suggests that inexpensive conservative interventions may have a beneficial effect. Ongoing research in large, well-controlled randomized clinical trials is needed to develop optimal strategies.

Study Strengths / Weaknesses:

The authors provide strong support for inexpensive and ease of use methods for measuring hyperkyphosis, therapeutic intervention and addressing this dysfunction amongst aging women and men. The information provided can provide a clinician with a preventive/treatment approach that can be readily incorporated into a clinical setting to improve patient care. Future research should improve protocols and enhanced prevention and treatment approaches.

Additional References:

  1. Lunden KM et al. Interrater and intrarater reliability in the measurement of kyphosis in postmenopausal women with osteoporosis. Spine. 1998; 23: 1978-1985.
  2. Huang MH et al. Hyperkyphotic posture and risk of future osteoporotic fractures: the Rancho Bernardo study. J Bone Miner Res. 2006; 21: 419-423.
  3. Katzman et al. Changes in flexed posture, musculoskeletal impairments, and physical performance after group exercise in community dwelling older women. Arch Phys Med Rehabil. 2007; 88: 192-199.