Thoracic kyphosis affects spinal loads and trunk muscle force

Effectiveness of mid-thoracic spine mobilization versus therapeutic exercise in patients with subacute stroke: A randomized clinical trial

BACKGROUND

Although commonly used in clinical settings, evidence regarding the beneficial effectiveness of joint mobilization and therapeutic exercise in patients with stroke is still lacking.

OBJECTIVE

This study aimed to investigate the effects of mid-thoracic spine mobilization and therapeutic exercise on dynamic balance and inspiratory function in patients with subacute stroke.

METHODS

The participants included 33 patients with subacute stroke. Participants were randomly allocated to 1 of 2 groups: (1) a group that received segmental mobilization (T4-8), and (2) a group that received foam roller exercises (T4-8). Outcome measure included the limits of stability (LOS), inspiratory function, and global rating of change (GRC).

RESULTS

The improvement in inspiratory function was statistically significant at 4 and 6 weeks after the initiation of the intervention and changes in the LOS were statistically significant at 6 weeks in the mobilization group (p< 0.05). In addition, 15 of 17 (88.2%) participants in the mobilization group, compared to 9 of 16 participants (56.2%) in the exercise group, indicated a GRC score of +4 or higher at the 4-week follow-up.

CONCLUSIONS

This study demonstrates that patients with subacute stroke who receive mid-thoracic spine mobilization demonstrate effective short-term improvements in LOS and GRC.

The influence of spinal fusion length on proximal junction biomechanics: a parametric computational study

PURPOSE

Proximal junctional kyphosis and failure are frequent complications in adult spinal deformity surgery with long fusion constructs. The aim of this study was to assess the biomechanics of the proximal segment for fusions of various lengths.

METHODS

A previously established musculoskeletal model of thoracolumbar spine was used to simulate full-range flexion task for fusions (modeled by introduction of rigid constraints) with lower instrumented vertebrae at L5 or S1 and upper instrumented vertebrae (UIV) at any level above, up to T2. Inverse dynamics simulations with force-dependent kinematics were performed for gradually increasing spinal flexion in order to predict global and segmental range of flexion, maximum passive moment, segmental compression and shear forces, which were compared to the uninstrumented case.

RESULTS

For long fusions, with the UIV at T11 or higher, the model predicted an increase in segmental flexion (by 33-860%, or 1.6°-4.7°) and passive moment (by 39-1370%, or 13-31 Nm) at the proximal junction-generally increasing with fusion length. While the maximum shear force was 57-239% (135-283 N) higher for the proximal junction at the upper thorax (UIV at T6 or above), the compression forces were reduced by up to 44% (375 N).

CONCLUSIONS

The length of the instrumentation has an important effect on the proximal segment biomechanics. Despite the limitations of the current model, musculoskeletal modeling appears to be a promising and versatile method to support planning of spinal instrumentation surgeries in the future. These slides can be retrieved under Electronic Supplementary Material.

Analysis of the Risk Factors for Unfavorable Radiologic Outcomes after Fusion Surgery in Thoracolumbar Burst Fracture : What Amount of Postoperative Thoracolumbar Kyphosis Correction is Reasonable?

Objective

The aims in the management of thoracolumbar spinal fractures are not only to restore vertebral column stability, but also to obtain acceptable alignment of the thoracolumbar junction (T-L junction) to prevent complications. However, insufficient surgical correction of the thoracolumbar spine would be likely to cause late progression of abnormal kyphosis. Therefore, we identified the surgical factors that affected unfavorable radiologic outcomes of the thoracolumbar spine after surgery.

Methods

This study was conducted in a single institution from January 2007 to December 2013. A total of 98 patients with unstable thoracolumbar spine fracture were included. In these patients, fixation was done through transpedicular screws with rods by three surgical patterns. We reviewed digital radiographs and analyzed the images preoperatively and postoperatively during follow-up visits to compare the change of the thoracolumbar Cobb angle with radiologic parameters and clinical outcomes. The unfavorable radiologic group was defined as the patients who were measured as having greater than 20 degrees of thoracolumbar Cobb angle on the last follow-up, or who underwent kyphotic progression of thoracolumbar Cobb angle greater than 10 degrees from the immediate postoperative state to final follow-up, or who had overt instrument failure with/without additional surgery. We assessed the risk factors that affected the unfavorable radiologic outcomes.

Results

We had 43 patients with unfavorable radiologic outcomes, including 35 abnormal thoracolumbar alignments and 14 instrumental failures with/without additional surgery. The multivariate logistic regression test showed that immediate postoperative T-L junction Cobb angle less than 10.5 degrees was a statistically significant risk factor, as well as the presence of osteoporosis (p=0.017 and 0.049, respectively).

Conclusion

Insufficient correction of thoracolumbar kyphosis was considered to be a major factor of an unfavorable radiological outcome. The spinal surgeon should consider that having a T-L junction Cobb angle larger than 10.5 degrees immediately after surgery could result in an unfavorable radiological outcome, which is related to a poor clinical outcome.

Effects of postural taping on pain, function and quality of life following osteoporotic vertebral fractures-A feasibility trial

OBJECTIVE

Osteoporotic vertebral fractures (OVFs) are common and present a significant burden to patients and healthcare services. Poor posture can increase vertebral pressure, pain and the risk of further fractures. The aim of the present study was to investigate the effects of postural taping on pain, function and quality of life when used in addition to usual care.

METHODS

A feasibility randomized, controlled trial was carried out in men and women with at least one clinically diagnosed painful OVF. Participants were randomly allocated to use an adhesive postural taping device at home for 4 weeks or to continue with usual care. Outcomes assessed at baseline and 4 weeks included pain at rest and on movement (visual analogue scales [VASs]), and function and quality of life (Quality of Life Questionnaire of the European Foundation for Osteoporosis [QUALEFFO]). Health resource use and acceptability were explored using a specifically designed questionnaire.

RESULTS

Twenty-four participants completed the trial (taping, n = 13; control, n = 11). Groups were comparable in age, although the control group contained more men (n = 3 versus n = 0) and scored slightly lower on most outcome measures at baseline. Descriptive analysis favoured the taping group for most outcome measures. Effect sizes were small to medium (0.37, 0.45 and 0.66 for VAS rest, VAS movement and QUALEFFO, respectively).

CONCLUSIONS

The taping device demonstrated potential to improve pain and function. However, the findings need to be replicated in an appropriately powered study. The study procedures were largely acceptable. A more extensive pilot trial is recommended prior to a definitive trial.

The effect of positive sagittal spine balance and reconstruction surgery on standing balance

BACKGROUND

Positive sagittal spine balance (PSSB) may adversely influence standing balance in individuals with degenerative spine diseases. PSSB is often corrected with the help of spinal reconstructive surgeries involving multiple vertebral units.

RESEARCH QUESTION

This study investigated the effect of PSSB and reconstructive surgery on postural sway as a measure of standing balance. The secondary goal of this study was to investigate the effect of reconstructive surgery on lower limb kinematics.

METHODS

Subjects who underwent spinal reconstructive surgery for correction of PSSB greater than or equal to 7 cm participated in this study. Postural sway data while standing quietly for 20 s on a force platform were analyzed pre-operatively, 6-12 months and 24 months post-operatively.

RESULTS

Reconstructive surgery was successful in correcting PSSB in all individuals. There was a moderate correlation between PSSB and postural sway in the anterior-posterior (AP) direction before surgery (r = 0.58) and at 6-12 months post-surgery (r = 0.63). Reconstructive surgery had a significant main effect on postural sway in both the anterior-posterior (p < 0.009, F = 7.01) and medial-lateral directions (p < 0, F = 12.30). Reconstructive surgery also had a significant main effect on standing hip (p < 0, F = 17.01) and knee flexion (p < 0, F = 32.23).

SIGNIFICANCE

These results reveal that PSSB in persons with degenerative spinal conditions compromised postural balance, which improved after reconstructive surgery. Additionally, persons with PSSB adopted a crouch posture, which resolved after reconstructive surgery.

The effects of shoulder stabilization exercises and pectoralis minor stretching on balance and maximal shoulder muscle strength of healthy young adults with round shoulder posture

[Purpose] The purpose of this study was to analyze the effects of pectoralis minor stretching and shoulder strengthening with an elastic band on balance and maximal shoulder muscle strength in young adults with rounded shoulder posture. [Subjects and Methods] Nineteen subjects with rounded shoulder posture were randomly divided into 2 groups: a shoulder stabilization exercise group and a stretching exercise group. The groups performed each exercise for 40 minutes, 3 times a week, for 4 weeks. Static balance (eyes open and closed), dynamic balance (the limits of stability in 4 directions) and shoulder muscle strength in 5 directions were measure before and after the exercises. [Results] The stretching exercise demonstrated a significant difference between the pre- and post-exercise in the static balance with eyes closed and extension and horizontal abduction strength while the stabilization exercise demonstrated significant difference in the left and right directions between the pre- and post-exercise of the dynamic balance and flexion strength. The stabilization exercise demonstrated significant differences shown in the flexion between the pre- and post-test. [Conclusion] The shoulder stabilization and stretching exercises improved the static balance, dynamic balance, and muscle strength.

Relationship between sagittal spinal curves geometry and isokinetic trunk muscle strength in adults

PURPOSE

Sagittal spinal deviation has been reported to be a significant musculoskeletal problem affecting both genders and could develop at any age. Factors triggering this issue are still not well defined. The purpose of this study was to investigate the relationship between sagittal spine angles and isokinetic peak, average torque, and power of trunk muscles in asymptomatic adults.

METHODS

A convenient sample of 79 subjects with asymptomatic spine participated in this study. Thoracic and lumbar curves angles were measured using the Formetric 4D device. Thoracolumbar (T/L) ratio was calculated as an indicator of spine balance. Isokinetic peak and average torque and average power for trunk flexors and extensors were measured at 60°/s in seated and semi-standing test positions.

RESULTS

Lumbar curve angle was moderately inversely correlated (p < 0.001) with peak extension torque (ρ = - 0.532 and - 0.495 in seated and semi-standing positions, respectively) and peak flexion torque (ρ = - 0.604 and - 0.542 in seated and semi-standing positions, respectively). The T/L ratio was found to be significantly associated (p < 0.001) with trunk extension torque (ρ = 0.422 and 0.378 in seated and semi-standing positions, respectively) and trunk flexion torque (ρ = 0.396 and 0.321 in seated and semi-standing positions, respectively). Similarly, average torque and power measurements were significantly correlated with lumbar curve angle and T/L ratio.

CONCLUSIONS

Sagittal spine balance is associated with trunk muscles strength in adults, particularly, the lumbar spine muscles. Therefore, assessment of sagittal spinal balance and trunk muscles strength should be taken into consideration when designing rehabilitation programs for correction of sagittal spine curvature.

Estimating apparent maximum muscle stress of trunk extensor muscles in older adults using subject-specific musculoskeletal models

Maximum muscle stress (MMS) is a critical parameter in musculoskeletal modeling, defining the maximum force that a muscle of given size can produce. However, a wide range of MMS values have been reported in literature, and few studies have estimated MMS in trunk muscles. Due to widespread use of musculoskeletal models in studies of the spine and trunk, there is a need to determine reasonable magnitude and range of trunk MMS. We measured trunk extension strength in 49 participants over 65 years of age, surveyed participants about low back pain, and acquired quantitative computed tomography (QCT) scans of their lumbar spines. Trunk muscle morphology was assessed from QCT scans and used to create a subject-specific musculoskeletal model for each participant. Model-predicted extension strength was computed using a trunk muscle MMS of 100 N/cm² . The MMS of each subject-specific model was then adjusted until the measured strength matched the model-predicted strength (±20 N). We found that measured trunk extension strength was significantly higher in men. With the initial constant MMS value, the musculoskeletal model generally over-predicted trunk extension strength. By adjusting MMS on a subject-specific basis, we found apparent MMS values ranging from 40 to 130 N/cm² , with an average of 75.5 N/cm² for both men and women. Subjects with low back pain had lower apparent MMS than subjects with no back pain. This work incorporates a unique approach to estimate subject-specific trunk MMS values via musculoskeletal modeling and provides a useful insight into MMS variation. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:498-505, 2018.

Management of Spinal Deformities and Evidence of Treatment Effectiveness

INTRODUCTION

The review evaluates the up-to-date evidence for the treatment of spinal deformities, including scoliosis and hyperkyphosis in adolescents and adults.

MATERIAL AND METHODS

The PubMed database was searched for review articles, prospective controlled trials and randomized controlled trials related to the treatment of spinal deformities. Articles on syndromic scoliosis were excluded and so were the articles on hyperkyphosis of the spine with causes other than Scheuermann's disease and osteoporosis. Articles on conservative and surgical treatments of idiopathic scoliosis, adult scoliosis and hyperkyphosis were also included. For retrospective papers, only studies with a follow up period exceeding 10 years were included.

RESULTS

The review showed that early-onset idiopathic scoliosis has a worse outcome than late-onset idiopathic scoliosis, which is rather benign. Patients with AIS function well as adults; they have no more health problems when compared to patients without scoliosis, other than a slight increase in back pain and aesthetic concern. Conservative treatment of adolescent idiopathic scoliosis (AIS) using physiotherapeutic scoliosis-specific exercises (PSSE), specifically PSSR and rigid bracing was supported by level I evidence. Yet to date, there is no high quality evidence (RCT`s) demonstrating that surgical treatment is superior to conservative treatment for the management of AIS. For adult scoliosis, there are only a few studies on the effectiveness of PSSEs and a conclusion cannot as yet be drawn.For hyperkyphosis, there is no high-quality evidence for physiotherapy, bracing or surgery for the treatment of adolescents and adults. However, bracing has been found to reduce thoracic hyperkyphosis, ranging from 55 to 80° in adolescents. In patients over the age of 60, bracing improves the balance score, and reduces spinal deformity and pain. Surgery is indicated in adolescents and adults in the presence of progression of kyphosis, refractory pain and loss of balance.

DISCUSSION

The available evidence reviewed has suggested that different approaches are needed towards the management of different spinal deformities. Specific exercises should be prescribed in children and adolescents with a Cobb angle in excess of 15°. In progressive curves, they should be used in conjunction with bracing. Clarity regarding differences and similarities is given as to what makes PSSE and PSSR specific exercises. As AIS is relatively benign in nature, conservative treatment should be tried when the curve is at a surgical threshold, before surgery is considered. Similarly, bracing and exercises should be prescribed for patients with hyperkyphosis, particularly when the lumbar spine is afflicted. Surgery should be considered only when the symptoms cannot be managed conservatively.

CONCLUSION

There is at present high quality evidence in support of the conservative treatment of AIS. The current evidence supports the use of PSSE, especially those using PSSR, together with bracing in the treatment of AIS. In view of the lack of medical consequences in adults with AIS, conservative treatment should be considered for curves exceeding the formerly assumed range of conservative indications.There is, however a lack of evidence in support of any treatment of choice for hyperkyphosis in adolescents and spinal deformities in adults. Yet, conservative treatment should be considered first. Yet to date, there is no high quality evidence (RCT`s) demonstrating that surgical treatment is superior to conservative treatment for the management of AIS and hyperkyphosis. Additionally, surgery needs to be considered with caution, as it is associated with a number of long-term complications.

Thoracolumbar spine loading associated with kinematics of the young and the elderly during activities of daily living

Excessive mechanical loading of the spine is a critical factor in vertebral fracture initiation. Most vertebral fractures develop spontaneously or due to mild trauma, as physiological loads during activities of daily living might exceed the failure load of osteoporotic vertebra. Spinal loading patterns are affected by vertebral kinematics, which differ between elderly and young individuals. In this study, the effects of age-related changes in spine kinematics on thoracolumbar spinal segmental loading during dynamic activities of daily living were investigated using combined experimental and modeling approach. Forty-four healthy volunteers were recruited into two age groups: young (N = 23, age = 27.1 ± 3.8) and elderly (N = 21, age = 70.1 ± 3.9). The spinal curvature was assessed with a skin-surface device and the kinematics of the spine and lower extremities were recorded during daily living tasks (flexion-extension and stand-sit-stand) with a motion capture system. The obtained data were used as input for a musculoskeletal model with a detailed thoracolumbar spine representation. To isolate the effect of kinematics on predicted loads, other model properties were kept constant. Inverse dynamics simulations were performed in the AnyBody Modeling System to estimate corresponding spinal loads. The maximum compressive loads predicted for the elderly motion patterns were lower than those of the young for L2/L3 and L3/L4 lumbar levels during flexion and for upper thoracic levels during stand-to-sit (T1/T2-T8/T9) and sit-to-stand (T3/T4-T6/T7). However, the maximum loads predicted for the lower thoracic levels (T9/T10-L1/L2), a common site of vertebral fractures, were similar compared to the young. Nevertheless, these loads acting on the vertebrae of reduced bone quality might contribute to a higher fracture risk for the elderly.

Reliability of novice physiotherapists for measuring Cobb angle using a digital method

BACKGROUND

The Cobb's method is the most accurate and reliable method for kyphosis measurement. Conventionally, a sagittal Cobb angle was commonly derived from a lateral plain film. With computer technology, a digital method is widely used in common clinical settings, but the existing reliability data involved only experienced raters.

OBJECTIVES

To assess the interrater and intrarater reliability of a digital Cobb's method using novice physiotherapists.

METHODS

Fifteen participants, with an occiput wall distance of more than 0 cm, were interviewed and assessed for their demographics. Then they were filmed for lateral spinal radiography over the area of thoracic spine in a standing position, and the Cobb angle was analyzed by four raters, including an expert physician and three novice physiotherapists, using a SurgimapSpine programme.

RESULTS

The average Cobb angles among the four raters showed no significant difference (p = 0.984). Outcomes of their measurements had excellent intrarater and interrater reliability [intraclass correlation coefficient (ICC3,3) = 0.995-0.997] with a small range of standard errors of the measurement (<1°).

CONCLUSION

A digital Cobb's method had excellent reliability when used by a novice health professional rater. The findings confirm the ease of using this method to detect and monitor kyphosis in general hospitals, clinics, or research facilities.

Incorporation of CT-based measurements of trunk anatomy into subject-specific musculoskeletal models of the spine influences vertebral loading predictions

We created subject-specific musculoskeletal models of the thoracolumbar spine by incorporating spine curvature and muscle morphology measurements from computed tomography (CT) scans to determine the degree to which vertebral compressive and shear loading estimates are sensitive to variations in trunk anatomy. We measured spine curvature and trunk muscle morphology using spine CT scans of 125 men, and then created four different thoracolumbar spine models for each person: (i) height and weight adjusted (Ht/Wt models); (ii) height, weight, and spine curvature adjusted (+C models); (iii) height, weight, and muscle morphology adjusted (+M models); and (iv) height, weight, spine curvature, and muscle morphology adjusted (+CM models). We determined vertebral compressive and shear loading at three regions of the spine (T8, T12, and L3) for four different activities. Vertebral compressive loads predicted by the subject-specific CT-based musculoskeletal models were between 54% lower to 45% higher from those estimated using musculoskeletal models adjusted only for subject height and weight. The impact of subject-specific information on vertebral loading estimates varied with the activity and spinal region. Vertebral loading estimates were more sensitive to incorporation of subject-specific spinal curvature than subject-specific muscle morphology. Our results indicate that individual variations in spine curvature and trunk muscle morphology can have a major impact on estimated vertebral compressive and shear loads, and thus should be accounted for when estimating subject-specific vertebral loading. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2164-2173, 2017.

A shared biomechanical environment for bone and posture development in children

BACKGROUND CONTEXT

In each specific habitual standing posture, gravitational forces determine the mechanical setting provided to skeletal structures. Bone quality and resistance to physical stress is highly determined by habitual mechanical stimulation. However, the relationship between bone properties and sagittal posture has never been studied in children.

PURPOSE

This study aimed to investigate the association between bone physical properties and sagittal standing postural patterns in 7-year-old children. We also analyzed the relationship between fat or fat-free mass and postural patterns.

STUDY DESIGN

Cross-sectional evaluation.

PATIENT SAMPLE

This study was performed in a sample of 1,138 girls and 1,260 boys at 7 years of age participating in the Generation XXI study, a population-based cohort of children followed since birth (2005-2006) and recruited in Porto, Portugal.

OUTCOME MEASURES

Sagittal standing posture was measured through photographs of the sagittal right view of children in the standing position. Three angles were considered to quantify the magnitude of major curves of the spine and an overall balance measure (trunk, lumbar, and sway angles). Postural patterns were identified using latent profile analysis in Mplus.

METHODS

Weight and height were measured. Total body less head fat or fat-free mass and bone properties were estimated from whole-body dual-energy X-ray absorptiometry scans. The associations of fat or fat-free mass and bone physical properties with postural patterns were jointly estimated in latent profile analysis using multinomial logistic regressions.

RESULTS

The identified patterns were labeled as Sway, Flat, and "Neutral to Hyperlordotic" (in girls), and "Sway to Neutral," Flat, and Hyperlordotic (in boys). In both genders, children in the Flat pattern showed the lowest body mass index, and children with a rounded posture presented the highest: mean differences varying from -0.86 kg/m² to 0.60 kg/m² in girls and from -0.70 kg/m² to 0.62 kg/m² in boys (vs. Sway or "Sway to Neutral"). Fat and fat-free mass were inversely associated with a Flat pattern and positively associated with a rounded posture: odds ratio (OR) of 0.23 per standard deviation (SD) fat and 0.70 per SD fat-free mass for the Flat pattern, and 1.85 (fat) and 1.43 (fat-free) for the Hyperlordotic pattern in boys, with similar findings in girls. The same direction of relationships was observed between bone physical properties and postural patterns. A positive association between bone (especially bone mineral density) and a rounded posture was robust to adjustment for age, height, and body composition (girls: OR=1.79, p=.006 fat-adjusted, OR=2.00, p=.014 fat-free mass adjusted; boys: OR=2.02, p=.002 fat-adjusted, OR=2.42, p<.001 fat-free mass adjusted).

CONCLUSIONS

In this population-based pediatric setting, there was an inverse association between bone physical properties and a Flat posture. Bone and posture were more strongly positively linked in a rounded posture. Our results support that both bone properties and posture mature in a shared and interrelated mechanical environment, probably modulated by pattern-specific anthropometrics and body composition.

Association Between Forward Head, Rounded Shoulders, and Increased Thoracic Kyphosis: A Review of the Literature

Objective

The purpose of this review was to explore the association between forward head posture, rounded shoulders, and increased thoracic kyphosis.

Methods

The PubMed, ERIC, and Cochrane databases were searched using the key words posture, head, shoulder, forward scapular posture, and thoracic kyphosis through December 2016.

Results

Our initial search yielded 6840 research studies, 6769 of which were excluded because they either were duplicates or did not satisfy the inclusion criteria. After the abstracts of the remaining studies were read, 15 were assessed for eligibility, and only 4 papers were included in the present review. Cervical lordosis values were found to be significantly associated with thoracic kyphosis values. Also, there were significant correlations between rounded shoulders and increased thoracic kyphosis.

Conclusion

Forward head posture, rounded shoulders, and increased thoracic kyphosis can exist alone or in any combination.

Thoracic Kyphosis and Physical Function: The Framingham Study

OBJECTIVE

To evaluate the association between thoracic kyphosis and physical function.

DESIGN

Prospective cohort.

SETTING

Framingham, Massachusetts.

PARTICIPANTS

Framingham Heart Study Offspring and Third Generation cohort members who had computed tomography (CT) performed between 2002 and 2005 and physical function assessed a mean 3.4 years later (N = 1,100; mean age 61 ± 8, range 50-85).

MEASUREMENTS

Thoracic kyphosis (Cobb angle, T4-T12) was measured in degrees using supine CT scout images. Participants were categorized according to Cobb angle to compare those in the highest quartile (Q4, most-severe kyphosis) with those in the lowest quartiles (Q1-Q3). Quick walking speed (m/s), chair-stand time (seconds), grip strength (kg), and self-reported impairments were assessed using standardized procedures. Analyses were adjusted for age, height, weight, smoking, follow-up time, vertebral fractures, and prevalent spinal degeneration.

RESULTS

Thoracic kyphosis was not associated with physical function in women or men, and these results were consistent in those younger than 65 and those aged 65 and older. For example, walking speed was similar in adults younger than 65 with and without severe kyphosis (women, Q4: 1.38 m/s, Q1-Q3: 1.40 m/s, P = .69; men, Q4: 1.65 m/s, Q1-Q3: 1.60 m/s; P = .39).

CONCLUSION

In healthy relatively high-functioning women and men, kyphosis severity was not associated with subsequent physical function. Individuals at risk of functional decline cannot be targeted based on supine CT thoracic curvature measures alone.

Age-related hyperkyphosis: update of its potential causes and clinical impacts-narrative review

The present study aims to qualitatively review the contributing factors and health implications of age-related hyperkyphosis. We conducted a narrative review of observational and cohort studies describing the risk factors and epidemiology of hyperkyphosis from 1955 to 2016 using the following key words: kyphosis, hyperkyphosis, posture, age-related hyperkyphosis, kyphotic posture, aetiology and causes. This review included 77 studies. Approximately 60-70 % of the most severe hyperkyphosis cases have no evidence of underlying vertebral compression fractures. Other proposed factors contributing to hyperkyphosis are degenerative disc disease, weakness of back extensor muscles and genetic predisposition. Strength and endurance of back extensor muscles are very important for maintaining normal postural alignment. Recent evidence suggests that age-related hyperkyphosis is not equivalent to spinal osteoporosis. Due to the negative impact of hyperkyphosis on physical function, quality of life and mortality rates, physicians should focus not only on osteoporosis, but also on age-related postural changes. More research about the relationship between spinal morphology and modifiable factors, especially the structural and functional parameters of trunk muscles, could further illuminate our understanding and treatment options for hyperkyphosis.

Spinal Loading Patterns From Biomechanical Modeling Explain the High Incidence of Vertebral Fractures in the Thoracolumbar Region

Vertebral fractures occur most frequently in the mid-thoracic and thoracolumbar regions of the spine, yet the reasons for this site-specific occurrence are not known. Our working hypothesis is that the locations of vertebral fracture may be explained by the pattern of spine loading, such that during daily activities the mid-thoracic and thoracolumbar regions experience preferentially higher mechanical loading compared to other spine regions. To test this hypothesis, we used a female musculoskeletal model of the full thoracolumbar spine and rib cage to estimate the variation in vertebral compressive loads and associated factor-of-risk (load-to-strength ratio) throughout the spine for 119 activities of daily living, while also parametrically varying spine curvature (high, average, low, and zero thoracic kyphosis models). We found that nearly all activities produced loading peaks in the thoracolumbar and lower lumbar regions of the spine, but that the highest factor-of-risk values generally occurred in the thoracolumbar region of the spine because these vertebrae had lower compressive strength than vertebrae in the lumbar spine. The peaks in compressive loading and factor-of-risk in the thoracolumbar region were accentuated by increasing thoracic kyphosis. Activation of the multifidus muscle fascicles selectively in the thoracolumbar region appeared to be the main contributor to the relatively high vertebral compressive loading in the thoracolumbar spine. In summary, by using advanced musculoskeletal modeling to estimate vertebral loading throughout the spine, this study provides a biomechanical mechanism for the higher incidence of fractures in thoracolumbar vertebrae compared to other spinal regions. © 2017 American Society for Bone and Mineral Research.

The influence of a semi-reclined seated posture on head and neck kinematics and muscle activity while reading a tablet computer

Increased tablet computer usage calls for a proper understanding of potential injury risks from these devices. The purpose of this study was to assess the influence of tablet computer reading postures on head and neck flexion and muscle activity. Nineteen participants completed read a tablet computer in four different postures (standard computer monitor, tablet on a desk, tablet in the lap, semi-reclined with tablet in the lap). Reading the tablet in a semi-reclined trunk posture with the tablet in one's lap increased (p < 0.001) neck flexion angle (71.6%ROM) relative to reading from the standard computer monitor (6.39%ROM). Head flexion in the semi-reclined posture (19.7%ROM) and muscle activity (8.88%MVC) were similar to when reading from a standard computer monitor. Despite potentially reducing the gravitational moment produced by the head, the semi-reclined position could still compromise the force capabilities of the neck extensor musculature and result in increased strain on the passive tissues of the spine. Future work should assess how the semi-reclined position influences cervical intervertebral angles and passive tissue properties of the cervical spine. Overall, more research needs to be conducted on thoracic spine kinematics while reading a tablet computer.

Magnetic Resonance Imaging and Spectroscopy to Assess Leg Muscle Macrostructure and Microstructure in Healthy Older Women: A Feasibility Assessment

BACKGROUND

Advanced magnetic resonance (MR) scanning techniques, such as diffusion tensor imaging (DTI) and proton MR spectroscopy (¹H-MRS) permit microstructural evaluation of water diffusivity and intramyocellular lipid content, respectively. We aimed to determine the feasibility of performing advanced MR scanning (proton density [PD] weighted imaging, DTI, and ¹H-MRS) to evaluate properties of leg muscles in older women with respect to: (1) participant recruitment using three community-based strategies; (2) participant tolerance to the MRI scan acquisition protocol; and (3) scan acquisition and analyses protocols.

METHODS

Recruitment feasibility was evaluated based on the number of participants enrolled using various strategies. Participant tolerance was feasible if the scanning session was uninterrupted and image artifacts were absent. Optimal PD imaging, DTI, and ¹H-MRS acquisition and analyses protocols were established.

RESULTS

Nine women (mean age = 71 years) were recruited over four months. The acquisition protocol was well tolerated by all participants. Adaptations were required for women with short stature and vertebral fracture risk. PD-weighted image analyses were improved by using the phased array uniformity enhancement filter to increase tissue contrast.

CONCLUSIONS

It is feasible to use a combination of MR scanning methods to evaluate muscle macrostructure and microstructure in the leg of older women. Our findings suggest that advanced MR scanning methods can be used for future studies interested in quantifying components of muscle structure in older women, but prospective studies are needed to confirm whether change in microstructure can be detected in response to an intervention.

Breast size impacts spine motion and postural muscle activation

BACKGROUND

While it is generally accepted that large breast sizes in females contribute to back pain and poor posture, the effects of breast size on spinal motion and muscle activation characteristics are poorly understood.

OBJECTIVE

This study examined the relationship between breast size, spine motion, and trunk muscle activation.

METHODS

Fifteen university-aged females, free of back pain symptoms, were tested. Breast sizes were calculated, and three-dimensional spine motion and activation from five trunk muscles bilaterally were measured during standing and trunk flexion movements. Correlations between breast size and motion and muscle activation measures were assessed.

RESULTS

Head and trunk angles were strongly, negatively correlated to breast size during upright standing; thoracic angles were moderately, positively correlated to breast size during thoracic flexion movements. Trunk muscles showed positive, moderate-strength relationships with breast size during upright standing and some trunk movements.

CONCLUSIONS

These findings provide a preliminary indication that increasing breast sizes are associated with altered postures and increased muscle activation in a non-clinical population, and constitute a baseline for the study of females with a full range of breast sizes. Further research is required to confirm the generalizability of these findings to other sizes, in order to inform strategies for the prevention or reduction of back pain, as well as diagnosis, treatment, and rehabilitation techniques associated with breast size and back pain.

Effect of the craniocervical brace on craniocervical angle, thoracic kyphosis angle, and trunk extensor muscle activity during typing in subjects with forward head posture

BACKGROUND

The relationship between forward head posture (FHP) and thoracic kyphosis has been a subject of interest in the rehabilitation field for visual display terminal workers.

OBJECTIVE

The aim of this study was to investigate the immediate effects of the craniocervical brace use on craniocervical angle (CCA), thoracic kyphosis angle (TKA), and trunk extensor muscle activity.

METHODS

Twelve young male subjects with forward head posture (21.6±1.9 years) participated in this study. We compared CCA & TKA and trunk extensor muscle activity between with and without application of the craniocervical brace during visual display terminal work.

RESULTS

When wearing the craniocervical brace, the subjects demonstrated significantly greater CCA at the start and the end of the task and less change in CCA during the task (p < 0.05). While non-significantly less TKA was seen at the start of the task, significantly less TKA was observed at the end of the task when using the craniocervical brace (p < 0.05). The craniocervical brace use also led to significantly less change in TKA (p < 0.05). There was no significant difference in the trunk extensor muscle activity.

CONCLUSIONS

Use of the craniocervical brace decreased FHP immediately, lessened thoracic kyphosis over time, and prevented the worsening of FHP and thoracic kyphosis during visual display terminal work.

Vertebral body or intervertebral disc wedging: which contributes more to thoracolumbar kyphosis in ankylosing spondylitis patients?: A retrospective study

Both vertebral body wedging and disc wedging are found in ankylosing spondylitis (AS) patients with thoracolumbar kyphosis. However, their relative contribution to thoracolumbar kyphosis is not fully understood. The objective of this study was to compare different contributions of vertebral and disc wedging to the thoracolumbar kyphosis in AS patients, and to analyze the relationship between the apical vertebral wedging angle and thoracolumbar kyphosis.From October 2009 to October 2013, a total of 59 consecutive AS patients with thoracolumbar kyphosis with a mean age of 38.1 years were recruited in this study. Based on global kyphosis (GK), 26 patients with GK < 70° were assigned to group A, and the other 33 patients with GK ≥ 70° were included in group B. Each GK was divided into disc wedge angles and vertebral wedge angles. The wedging angle of each disc and vertebra comprising the thoracolumbar kyphosis was measured, and the proportion of the wedging angle to the GK was calculated accordingly. Intergroup and intragroup comparisons were subsequently performed to investigate the different contributions of disc and vertebra to the GK. The correlation between the apical vertebral wedging angle and GK was calculated by Pearson correlation analysis. The duration of disease and sex were also recorded in this study.With respect to the mean disease duration, significant difference was observed between the two groups (P < 0.01). The wedging angle and wedging percentage of discs were significantly higher than those of vertebrae in group A (34.8° ± 2.5° vs 26.7° ± 2.7°, P < 0.01 and 56.6% vs 43.4%, P < 0.01), whereas disc wedging and disc wedging percentage were significantly lower than vertebrae in group B (37.6° ± 7.0° vs 50.1° ± 5.1°, P < 0.01 and 42.7% vs 57.3%, P < 0.01). The wedging of vertebrae was significantly higher in group B than in group A (50.1° ± 5.1° vs 26.7° ± 2.7°, P < 0.01). Additionally, correlation analysis revealed a significant correlation between the apical vertebral wedging angle and GK (R = 0.850, P = 0.001).Various disc and vertebral wedging exist in thoracolumbar kyphosis secondary to AS. The discs wedging contributes more to the thoracolumbar kyphosis in patients with GK < 70° than vertebral wedging, whereas vertebral wedging is more conducive to the thoracolumbar kyphosis in patients with GK ≥ 70°, indicating different biomechanical pathogenesis in varied severity of thoracolumbar kyphosis secondary to AS.

Thoracic kyphosis and rate of incident vertebral fractures: the Fracture Intervention Trial

SUMMARY

Biomechanical analyses support the theory that thoracic spine hyperkyphosis may increase risk of new vertebral fractures. While greater kyphosis was associated with an increased rate of incident vertebral fractures, our analysis does not show an independent association of kyphosis on incident fracture, after adjustment for prevalent vertebral fracture. Excessive kyphosis may still be a clinical marker for prevalent vertebral fracture.

INTRODUCTION

Biomechanical analyses suggest hyperkyphosis may increase risk of incident vertebral fracture by increasing the load on vertebral bodies during daily activities. We propose to assess the association of kyphosis with incident radiographic vertebral fracture.

METHODS

We used data from the Fracture Intervention Trial among 3038 women 55-81 years of age with low bone mineral density (BMD). Baseline kyphosis angle was measured using a Debrunner kyphometer. Vertebral fractures were assessed at baseline and follow-up from lateral radiographs of the thoracic and lumbar spine. We used Poisson models to estimate the independent association of kyphosis with incident fracture, controlling for age and femoral neck BMD.

RESULTS

Mean baseline kyphosis was 48° (SD = 12) (range 7-83). At baseline, 962 (32%) participants had a prevalent fracture. There were 221 incident fractures over a median of 4 years. At baseline, prevalent fracture was associated with 3.7° greater average kyphosis (95% CI 2.8-4.6, p < 0.0005), adjusting for age and femoral neck BMD. Before adjusting for prevalent fracture, each 10° greater kyphosis was associated with 22% increase (95% CI 8-38%, p = 0.001) in annualized rate of new radiographic vertebral fracture, adjusting for age and femoral neck BMD. After additional adjustment for prevalent fracture, estimated increased annualized rate was attenuated and no longer significant, 8% per 10° kyphosis (95% CI -4 to 22%, p = 0.18).

CONCLUSIONS

While greater kyphosis increased the rate of incident vertebral fractures, our analysis does not show an independent association of kyphosis on incident fracture, after adjustment for prevalent vertebral fracture. Excessive kyphosis may still be a clinical marker for prevalent vertebral fracture.

Prospective study of spinal orthoses in women

BACKGROUND

There are not many clinical trials investigating the efficiency and compliance of using spinal orthoses in the management of osteoporosis.

OBJECTIVES

The purpose of this study was to investigate the effect of long-term use and the compliance of spinal orthoses in postmenopausal women with vertebral fractures.

STUDY DESIGN

Clinical trial of spinal orthoses in postmenopausal women.

METHODS

Women were separated into groups wearing different types of orthoses (Spinomed, Osteomed, Spinomed active, and Spine-X). Isometric maximum strength of trunk muscles (F/Wabdominals-extensors) was calculated and back pain was assessed in all women. In addition, women completed a compliance questionnaire about the use of the orthoses.

RESULTS

Spinomed decreased pain (p = 0.001) and increased trunk muscle strength (F/Wabdominals, p = 0.005 and F/Wextensors, p = 0.003, respectively). The compliance of wearing an orthosis for 6 months was 66%.

CONCLUSION

The results suggest that orthoses could be an effective intervention for back pain and muscle strengthening in osteoporotic women.

CLINICAL RELEVANCE

In women with established osteoporosis, wearing Spinomed orthosis for at least 2 h/day for 6 months decreased back pain significantly and increased personal isometric trunk muscle strength. All spinal orthoses could be valuable instruments to help all requested rehabilitation programs like spine muscles' strengthening and postural correct behavior, but only when used properly.

Development and Validation of a Musculoskeletal Model of the Fully Articulated Thoracolumbar Spine and Rib Cage

We developed and validated a fully articulated model of the thoracolumbar spine in opensim that includes the individual vertebrae, ribs, and sternum. To ensure trunk muscles in the model accurately represent muscles in vivo, we used a novel approach to adjust muscle cross-sectional area (CSA) and position using computed tomography (CT) scans of the trunk sampled from a community-based cohort. Model predictions of vertebral compressive loading and trunk muscle tension were highly correlated to previous in vivo measures of intradiscal pressure (IDP), vertebral loading from telemeterized implants and trunk muscle myoelectric activity recorded by electromyography (EMG).

THE BIOMECHANICAL EFFECTS OF CEMENT AUGMENTATION AND PARTIAL VERTEBRAL HEIGHT RESTORATION ON THE LOAD TRANSFER CHANGE OF ADJACENT VERTEBRAE IN VERTEBROPLASTY

Vertebroplasty is commonly used to treat vertebral wedge fractures (VWFs). However, differing degrees of vertebral height restoration (VHR) have been reported after vertebroplasty, and little is known about how grades (steepness) of VWF deformities affect loadings on the fractured and adjacent unfractured vertebrae. Therefore, the goal of this study was to create a non-linear finite element (FE) model of the T10–L2 thoracolumbar segments. With this model, we aimed to evaluate the biomechanical outcomes of three different collapse models (25%, 50%, and 75%) at the T12 vertebra before and after cement augmentation (CA) and with and without VHR. In these VWF simulations, the forces of the erector spinae, the intradiscal pressure, and the maximum von Mises stresses in the endplates and vertebral bodies increased as vertebral deformation increased. Performing CA alone, without restoring vertebral height for the fractured vertebra, did not change the stiffness of multiple spinal segments or the pressures on the adjacent disc, but it did decrease stresses on the endplates and the vertebral bone. A 10% restoration of vertebral height after CA reduced the maximum von Mises stress in the endplates and bone structures more than when CA did not restore vertebral height (no VHR). These results suggest that achieving partial VHR during vertebroplasty may help prevent postvertebroplasty fractures in the fractured and adjacent vertebrae.

Association between kyphosis and subacromial impingement syndrome: LOHAS study

BACKGROUND

Kyphosis is a cause of scapular dyskinesis, which can induce various shoulder disorders, including subacromial impingement syndrome (SIS). This study aimed to clarify the impact of kyphosis on SIS with use of cross-sectional data from the Locomotive Syndrome and Health Outcome in Aizu Cohort Study (LOHAS).

METHODS

The study enrolled 2144 participants who were older than 40 years and participated in health checkups in 2010. Kyphosis was assessed by the wall-occiput test (WOT) for thoracic kyphosis and the rib-pelvic distance test (RPDT) for lumbar kyphosis. The associations between kyphosis, SIS, and reduction in shoulder elevation (RSE) were investigated.

RESULTS

Age- and gender-adjusted logistic regression analysis demonstrated significant association between SIS and WOT (odds ratio, 1.65; 95% confidence interval, 1.02, 2.64; P < .05), whereas there was no significant association between SIS and RPDT. Multivariable logistic regression analysis demonstrated no significant association between SIS and both WOT and RPDT, whereas there was significant association between SIS and RSE.

CONCLUSION

RSE plays a key role in the development of SIS, and thoracic kyphosis might influence the development of SIS indirectly by reducing shoulder elevation induced by the restriction of the thoracic spine extension and scapular dyskinesis.

Comparison of radiological and clinical results of balloon kyphoplasty according to anterior height loss in the osteoporotic vertebral fracture

BACKGROUND CONTEXT

Percutaneous kyphoplasty is effective for pain reduction and vertebral height restoration in patients with osteoporotic vertebral fractures. However, in cases of severely collapsed fractures involving the loss of more than 70% of the vertebral height, kyphoplasty is technically difficult to perform and the outcomes remain unknown.

PURPOSE

To compare the vertebral height restoration rate, kyphotic angle, and clinical results of patients who underwent kyphoplasty according to the degree of anterior vertebral height loss. In addition, to determine the feasibility and effects of kyphoplasty on severely collapsed osteoporotic vertebral fractures.

STUDY DESIGN/SETTING

A retrospective study.

PATIENT SAMPLE

A total of 129 patients (145 vertebrae) who underwent kyphoplasty for osteoporotic painful vertebral fracture and followed up for more than 1 year between September 2005 and August 2012 were recruited for the analysis.

OUTCOME MEASURES

The patients' kyphotic angle, anterior vertebral height, and anterior vertebral height restoration ratio 1 year after surgery were compared. Pre- and postoperative pain around the fractured vertebra and the radiological and clinical results according to bone mineral density (BMD) were also compared.

METHODS

Patients were divided into three groups for comparison, according to radiographic findings. Patients with an anterior height compression ratio more than 70% at the time of fracture comprised Group I, patients with a compression ratio of 50-70% comprised Group II, and those with a compression ratio of 30-50% comprised Group III.

RESULTS

Group I showed a greater extent of anterior height restoration immediately after surgery compared with the other groups, which noticeably decreased over time. All three groups showed significant restoration of the anterior vertebral height between pre- and postoperative values. The anterior vertebral height 1 year after surgery did not differ between Group I and Group II but was significantly higher in Group III. There was no correlation between the BMD and restoration or decrease of anterior vertebral height over time. Pain around the fractured vertebra significantly decreased in all groups immediately and 1 year after surgery compared with preoperative levels, although the pain level 1 year after surgery did not differ significantly between the groups.

CONCLUSIONS

In patients with an anterior vertebral compression ratio more than 70% because of osteoporotic vertebral fracture, although the anterior height and kyphotic angle were significantly lower than those of patients with an anterior vertebral compression ratio of 30% to 50%, kyphoplasty significantly improved the degree of pain, restored the anterior vertebral height, and maintained the kyphotic angle. Therefore, kyphoplasty can be a useful approach in patients with an anterior vertebral compression ratio more than 70%.

Influence of thoracic flexion syndrome on proprioception in the thoracic spine

[Purpose] This study was performed to determine the difference in thoracic repositioning sense in young people with and without thoracic flexion syndrome (TFS) in target positions of half extension. [Subjects] People with TFS (n = 15; 7 men and 8 women) and people without TFS (n = 15; 7 men and 8 women) were recruited from three universities. Subjects were guided into a sitting extension target posture and were asked to move from a neutral position (2 s) to an extension target position (2 s); 10 trials were performed. [Results] People with TFS showed a significantly higher thoracic repositioning error in the extension target position than people without TFS. [Conclusion] People with TFS show a higher thoracic spine repositioning error in extension than people without TFS. A rehabilitation program to treat TFS should be implemented for individuals with decreased position sense of the thoracic spine.

Spine curvature analysis between participants with obesity and normal weight participants: a biplanar electromagnetic device measurement

To analyse and compare standing thoracolumbar curves in normal weight participants and participants with obesity, using an electromagnetic device, and to analyse the measurement reliability.

MATERIAL AND METHODS

Cross-sectional study was carried out. 36 individuals were divided into two groups (normal-weight and participants with obesity) according to their waist circumference. The reference points (T1-T8-L1-L5 and both posterior superior iliac spines) were used to perform a description of thoracolumbar curvature in the sagittal and coronal planes. A transformation from the global coordinate system was performed and thoracolumbar curves were adjusted by fifth-order polynomial equations. The tangents of the first and fifth lumbar vertebrae and the first thoracic vertebra were determined from their derivatives. The reliability of the measurement was assessed according to the internal consistency of the measure and the thoracolumbar curvature angles were compared between groups.

RESULTS

Cronbach's alpha values ranged between 0.824 (95% CI: 0.776-0.847) and 0.918 (95% CI: 0.903-0.949). In the coronal plane, no significant differences were found between groups; however, in sagittal plane, significant differences were observed for thoracic kyphosis.

CONCLUSION

There were significant differences in thoracic kyphosis in the sagittal plane between two groups of young adults grouped according to their waist circumference.

Evidence-informed physical therapy management of performance-related musculoskeletal disorders in musicians

Playing a musical instrument at an elite level is a highly complex motor skill. The regular daily training loads resulting from practice, rehearsals and performances place great demands on the neuromusculoskeletal systems of the body. As a consequence, performance-related musculoskeletal disorders (PRMDs) are globally recognized as common phenomena amongst professional orchestral musicians. These disorders create a significant financial burden to individuals and orchestras as well as lead to serious consequences to the musicians’ performance and ultimately their career. Physical therapists are experts in treating musculoskeletal injuries and are ideally placed to apply their skills to manage PRMDs in this hyper-functioning population, but there is little available evidence to guide specific injury management approaches. An Australia-wide survey of professional orchestral musicians revealed that the musicians attributed excessively high or sudden increase in playing-load as major contributors to their PRMDs. Therefore, facilitating musicians to better manage these loads should be a cornerstone of physical therapy management. The Sound Practice orchestral musicians work health and safety project used formative and process evaluation approaches to develop evidence-informed and clinically applicable physical therapy interventions, ultimately resulting in favorable outcomes. After these methodologies were employed, the intervention studies were conducted with a national cohort of professional musicians including: health education, onsite injury management, cross-training exercise regimes, performance postural analysis, and music performance biomechanics feedback. The outcomes of all these interventions will be discussed alongside a focussed review on the existing literature of these management strategies. Finally, a framework for best-practice physical therapy management of PRMDs in musicians will be provided.

Vertebral size, bone density, and strength in men and women matched for age and areal spine BMD

To explore the possible mechanisms underlying sex-specific differences in skeletal fragility that may be obscured by two-dimensional areal bone mineral density (aBMD) measures, we compared quantitative computed tomography (QCT)-based vertebral bone measures among pairs of men and women from the Framingham Heart Study Multidetector Computed Tomography Study who were matched for age and spine aBMD. Measurements included vertebral body cross-sectional area (CSA, cm(2) ), trabecular volumetric BMD (Tb.vBMD, g/cm(3) ), integral volumetric BMD (Int.vBMD, g/cm(3) ), estimated vertebral compressive loading and strength (Newtons) at L3 , the factor-of-risk (load-to-strength ratio), and vertebral fracture prevalence. We identified 981 male-female pairs (1:1 matching) matched on age (± 1 year) and QCT-derived aBMD of L3 (± 1%), with an average age of 51 years (range 34 to 81 years). Matched for aBMD and age, men had 20% larger vertebral CSA, lower Int.vBMD (-8%) and Tb.vBMD (-9%), 10% greater vertebral compressive strength, 24% greater vertebral compressive loading, and 12% greater factor-of-risk than women (p < 0.0001 for all), as well as higher prevalence of vertebral fracture. After adjusting for height and weight, the differences in CSA and volumetric bone mineral density (vBMD) between men and women were attenuated but remained significant, whereas compressive strength was no longer different. In conclusion, vertebral size, morphology, and density differ significantly between men and women matched for age and spine aBMD, suggesting that men and women attain the same aBMD by different mechanisms. These results provide novel information regarding sex-specific differences in mechanisms that underlie vertebral fragility.

Kyphosis and paraspinal muscle composition in older men: a cross-sectional study for the Osteoporotic Fractures in Men (MrOS) research group

Background

The prevalence of hyperkyphosis is increased in older men; however, risk factors other than age and vertebral fractures are not well established. We previously reported that poor paraspinal muscle composition contributes to more severe kyphosis in a cohort of both older men and women.

Methods

To specifically evaluate this association in older men, we conducted a cross-sectional study to evaluate the association of paraspinal muscle composition and degree of thoracic kyphosis in an analytic cohort of 475 randomly selected participants from the Osteoporotic Fractures in Men (MrOS) study with baseline abdominal quantitative computed tomography (QCT) scans and plain thoracic radiographs. Baseline abdominal QCT scans were used to obtain abdominal body composition measurements of paraspinal muscle and adipose tissue distribution. Supine lateral spine radiographs were used to measure Cobb angle of kyphosis. We examined the linear association of muscle volume, fat volume and kyphosis using loess plots. Multivariate linear models were used to investigate the association between muscle and kyphosis using total muscle volume, as well as individual components of the total muscle volume, including adipose and muscle compartments alone, controlling for age, height, vertebral fractures, and total hip bone mineral density (BMD). We examined these associations among those with no prevalent vertebral fracture and those with BMI < 30 kg/m².

Results

Among men in the analytic cohort, means (SD) were 74 (SD = 5.9) years for age, and 37.5 (SD = 11.9) degrees for Cobb angle of kyphosis. Men in the lowest tertile of total paraspinal muscle volume had greater mean Cobb angle than men in the highest tertile, although test of linear trend across tertiles did not reach statistical significance. Neither lower paraspinal skeletal muscle volume (p-trend = 0.08), or IMAT (p-trend = 0.96) was associated with greater kyphosis. Results were similar among those with no prevalent vertebral fractures. However, among men with BMI < 30 kg/m², those in the lowest tertile of paraspinal muscle volume had greater adjusted mean kyphosis (40.0, 95% CI: 37.8 – 42.1) compared to the highest tertile (36.3, 95% CI: 34.2 – 38.4).

Conclusions

These results suggest that differences in body composition may potentially influence kyphosis.

Classification system of the normal variation in sagittal standing plane alignment: a study among young adolescent boys

STUDY DESIGN

Cohort study.

OBJECTIVE

To construct a sagittal standing alignment classification system in which the clinical significance of identified subgroups was considered with spinal pain measures.

SUMMARY OF BACKGROUND DATA

Numerous grading systems for the categorization of sagittal standing alignment have been devised. However, no common consensus exists about which typology should be adopted. Furthermore, the clinical significance of proposed classification schemes has rarely been assessed in terms of their relationship with spinal pain. Given the importance of the adolescent period for musculoskeletal development, research within a young adolescent population is required.

METHODS

The study population consisted of 639 prepeak height velocity boys (mean age, 12.6 yr [standard deviation, 0.54 yr]). Sagittal posture was quantified during habitual standing; data were used to develop a classification system according to 3 gross postural and 5 lumbopelvic characteristics. Prevalence rates of spinal pain measures (pain and seeking care) were compared between postural subgroups.

RESULTS

Cluster analysis indicated 3 types of characteristic overall sagittal profiles: neutral global alignment (n = 266 [41.6%]), sway-back (n = 199 [31.1%]), and leaning-forward (n = 174 [27.2%]). Within each of these categories, postural subgroups could be established according to specific lumbopelvic features. Logistic regression revealed that prevalence (lifetime and month) of low back pain and neck pain was significantly higher in boys classified as having sway-back posture than in those classified as having neutral global alignment. Spinal pain measures did not differ between groups of the lumbopelvic subclassification.

CONCLUSION

Meaningful classifications exist for sagittal plane posture in young adolescent boys, both on gross body segment and lumbopelvic level. In terms of clinical importance, that is, low back pain and neck pain prevalence, postural subgrouping strategies based on the orientation of gross body segments are suggested to be superior when compared with lumbopelvic grading.

Exercise for improving age-related hyperkyphotic posture: a systematic review

OBJECTIVE

To evaluate previous research to determine if exercise can improve preexisting hyperkyphosis by decreasing the angle of thoracic kyphosis in adults aged ≥45 years.

DATA SOURCES

PubMed, Embase, and the Cumulative Index to Nursing and Allied Health Literature databases were searched for studies related to posture, exercise, and age ≥45 years. Online conference proceedings of the American Society for Bone and Mineral Research, American Physical Therapy Association, and Gerontological Society of America were also searched.

STUDY SELECTION

Two independent reviewers screened the titles and abstracts and selected studies that tested the effect of exercise on measures of kyphosis, or forward head posture, in individuals with hyperkyphosis at baseline (defined as angle of kyphosis ≥40°). Reviews, letters, notes, and non-English language studies were excluded.

DATA EXTRACTION

A pilot-tested abstraction form was used by each reviewer to extract data from each study regarding details of exercise intervention, participant characteristics, safety, adherence, and results. The Cochrane Collaboration's tool for assessing risk of bias was used to assess methodologic quality. Discrepancies on the abstraction forms between the 2 reviewers were resolved by a third reviewer. A formal meta-analysis was not performed.

DATA SYNTHESIS

Thirteen studies were abstracted and included in the review; of these, 8 studies saw improvements in ≥1 measure of posture. The main sources of bias were related to blinding participants and incomplete outcome data. The adherence reported across studies suggests that exercise is an acceptable intervention for individuals with age-related hyperkyphosis.

CONCLUSIONS

The scarcity and quality of available data did not permit a pooled estimate of the effect of exercise on hyperkyphotic posture; however, the positive effects observed in high-quality studies suggest some benefit and support the need for an adequately designed randomized controlled trial examining the effect of exercise on hyperkyphosis.

Movement coordination and differential kinematics of the cervical and thoracic spines in people with chronic neck pain

BACKGROUND

Research on the kinematics and inter-regional coordination of movements between the cervical and thoracic spines in motion adds to our understanding of the performance and interplay of these spinal regions. The purpose of this study was to examine the effects of chronic neck pain on the three-dimensional kinematics and coordination of the cervical and thoracic spines during active movements of the neck.

METHODS

Three-dimensional spinal kinematics and movement coordination between the cervical, upper thoracic, and lower thoracic spines were examined by electromagnetic motion sensors in thirty-four individuals with chronic neck pain and thirty-four age- and gender-matched asymptomatic subjects. All subjects performed a set of free active neck movements in three anatomical planes in sitting position and at their own pace. Spinal kinematic variables (angular displacement, velocity, and acceleration) of the three defined regions, and movement coordination between regions were determined and compared between the two groups.

FINDINGS

Subjects with chronic neck pain exhibited significantly decreased cervical angular velocity and acceleration of neck movement. Cross-correlation analysis revealed consistently lower degrees of coordination between the cervical and upper thoracic spines in the neck pain group. The loss of coordination was most apparent in angular velocity and acceleration of the spine.

INTERPRETATION

Assessment of the range of motion of the neck is not sufficient to reveal movement dysfunctions in chronic neck pain subjects. Evaluation of angular velocity and acceleration and movement coordination should be included to help develop clinical intervention strategies to promote restoration of differential kinematics and movement coordination.

Exercise for improving outcomes after osteoporotic vertebral fracture

BACKGROUND

Vertebral fractures are associated with increased morbidity (e.g., pain, reduced quality of life), and mortality. Therapeutic exercise is a non-pharmacologic conservative treatment that is often recommended for patients with vertebral fractures to reduce pain and restore functional movement.

OBJECTIVES

Our objectives were to evaluate the benefits and harms of exercise interventions of four weeks or greater (alone or as part of a physical therapyintervention) versus non-exercise/non-active physical therapy intervention, no intervention or placebo on the incidence of future fractures and adverse events among adults with a history of osteoporotic vertebral fracture(s). We were also examined the effects of exercise on the following secondary outcomes: falls, pain, posture,physical function, balance,mobility, muscle function,quality of life and bone mineral density of the lumbar spine or hip measured using dual-energy X-ray absorptiometry (DXA).We also reported exercise adherence.

SEARCH METHODS

We searched the following databases: The Cochrane Library ( Issue 11 of 12, November 2011), MEDLINE (2005 to 2011), EMBASE (1988 to November 23, 2011), CINAHL (Cumulative Index to Nursing and Allied Health Literature, 1982 to November 23, 2011), AMED (1985 to November 2011), and PEDro (Physiotherapy Evidence Database, www.pedro.fhs.usyd.edu.au/index.html, 1929 to November 23, 2011. Ongoing and recently completed trials were identified by searching the World Health Organization International Clinical Trials Registry Platform (to December 2009). Conference proceedings were searched via ISI and SCOPUS, and targeted searches of proceedings of the American Congress of Rehabilitation Medicine and American Society for Bone and Mineral Research. Search terms or MeSH headings included terms such as vertebral fracture AND exercise OR physical therapy.

SELECTION CRITERIA

We considered all randomized controlled trials and quasi-randomized trials comparing exercise or active physical therapy interventions with placebo/non-exercise/non-active physical therapy interventions or no intervention implemented in individuals with a history of vertebral fracture and evaluating the outcomes of interest.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials and extracted data using a pre-tested data abstraction form. Disagreements were resolved by consensus, or third party adjudication. The Cochrane Collaboration's tool for assessing risk of bias was used to evaluate each study. Studies were grouped according to duration of follow-up (i.e., a) four to 12 weeks; b) 16 to 24 weeks; and c) 52 weeks); a study could be represented in more than one group depending on the number of follow-up assessments. For continuous data, we report mean differences (MDs) of the change or percentage change from baseline. Data from two studies were pooled for one outcome using a fixed-effect model.

MAIN RESULTS

Seven trials (488 participants, four male participants) were included. Substantial variability across the seven trials prevented any meaningful pooling of data for most outcomes. No trials assessed the effect of exercise on incident fractures, adverse events or incident falls. Individual trials reported that exercise could improve pain, performance on the Timed Up and Go test, walking speed, back extensor strength, trunk muscle endurance, and quality of life. However, the findings should be interpreted with caution given that there were also reports of no significant difference between exercise and control groups for pain, Timed Up and Go test performance, trunk extensor muscle strength and quality of life. Pooled analyses from two studies revealed a significant between-group difference in favour of exercise for Timed Up and Go performance (MD -1.13 seconds, 95% confidence interval (CI) -1.85 to -0.42, P = 0.002). Individual studies also reported no significant between-group differences for posture or bone mineral density. Adherence to exercise varied across studies. The risk of bias across all studies was variable; low risk across most domains in four studies, and unclear or high risk in most domains for three studies.

AUTHORS' CONCLUSIONS

No definitive conclusions can be made regarding the benefits of exercise for individuals with vertebral fracture. Although individual trials did report benefits for some pain, physical function and quality of life outcomes, the findings should be interpreted with caution given that findings were inconsistent and the quality of evidence was very low. The small number of trials and variability across trials limited our ability to pool outcomes or make conclusions. Evidence regarding the effects of exercise after vertebral fracture, particularly for men, is scarce. A high-quality randomized trial is needed to inform exercise prescription for individuals with vertebral fractures.