Back Muscle Function in Older Women With Age-Related Hyperkyphosis: A Comparative Study

The Association Between Physical Function and Hyperkyphosis in Older Females: A Systematic Review and Meta-analysis

BACKGROUND AND PURPOSE

Thoracic hyperkyphosis may adversely influence physical function in older adults, but the literature is mixed and confounded by possible sex differences. This systematic review and meta-analysis aimed to examine the association between hyperkyphosis and physical function in older females.

METHODS

Scopus, ISI Web of Science, Cochrane Library, PubMed, CINAHL, and PEDro databases were searched through 2021 for studies that included measures of thoracic hyperkyphosis and physical function with extractable data for women older than 60 years. Studies were excluded if they were qualitative, case reports, case series, ecological studies, reviews, or were not published in English. The study quality and risk of bias were assessed using checklists from the National Heart, Lung, and Blood Institute. Data were synthesized using Cohen's d effect size and 95% confidence interval (CI), and random-effects models were used for the meta-analyses.

RESULTS AND DISCUSSION

Three cohort and 22 cross-sectional studies of fair to good quality met the inclusion criteria. Eight studies reporting single-group data showed a moderate association between greater kyphosis angles and lower physical function ( d = -0.57; 95% CI -0.73, -0.40). Fourteen studies reporting 2-group data showed a large negative effect on physical function for groups with greater kyphosis angles ( d = -1.16; 95% CI -1.53, -0.78). Three studies that reported multivariate data also tended to show negative associations between physical function and hyperkyphosis. Limitations include a relative lack of causal evidence; confirming causation requires additional longitudinal studies. Studies have assessed various physical function categories, including strength, gait, and balance. Future studies could determine the categories of function most affected so that preventive interventions could target hyperkyphosis appropriately.

CONCLUSIONS

Hyperkyphosis was associated with lower physical function in older women. Three cohort studies suggest that greater kyphosis angles may predict greater loss of physical function over time. These results imply that therapies that help to minimize hyperkyphosis may help preserve function in older women.

Which trunk muscle parameter is the best predictor for physical function in older adults?

Background

Despite preliminary evidence demonstrating the relevance of trunk muscle strength for physical function in older adults, it is not clear which muscle-related trunk parameter is the best predictor for physical functions. Therefore, this study aimed to compare trunk muscle morphology or strength parameters regarding their predictive ability for physical functions.

Methods

Seventy-four older adults (38 men, 36 women, mean age 76.85 years) were tested for maximum absolute and relative isokinetic trunk flexion and extension strength, trunk lean mass, and trunk muscle quality. Functional assessment included normal and fast walking speed, repeated sit-to-stand transfer, timed up and go, and postural sway during a closed-feet and a semi-tandem stance adjusted for body height. Pearson's correlations were used to compare relationship between trunk strength adjusted and unadjusted for body weight to physical functions. Linear regression analysis including sex and age as co-variables was performed between trunk muscle and functional test parameters.

Results

Relative back extension strength was the most consistent significant predictor for all physical function tests (p = 0.004-0.04) except for postural sway. Relative trunk flexion strength was related to normal walking speed (p = 0.024). Trunk lean mass was related to timed up and go performance (p = 0.024).

Conclusion

Relative back extension strength is associated with better performance in nearly all standard tests for physical function in older adults, while trunk flexion strength and lean mass seem to play a minor role. Our findings emphasize the importance of trunk muscle strength, especially the back extensor muscles, for physical function in older adults.

The occurrence of flexion-relaxation phenomenon in elite cyclists during trunk forward bending

Flexion-relaxation phenomenon (FRP) is a well-known phenomenon in spinal extensor muscles. According to the literature, prolonged flexed posture leads to creep phenomenon and affects the active and passive neuromuscular control of the spinal column. The purpose of this study was to investigate FRP occurrence in elite cyclists that prolonged flexion posture is an integral part of their professional life. Their muscles' contraction pattern during forward bending was also compared. Electromyography (EMG) was recorded during flexion and extension from standing position in thoracic erector spinae (TES), lumbar erector spinae (LES) and gluteus maximus (Gluteus max) in 15 healthy male elite cyclists. In addition, the kinematic data related to the trunk angles were simultaneously recorded by a motion analysis system. Two-way ANOVA was used to assess the effects of muscle group and direction of movement on maximum amplitude of EMG activity. Among 15 cyclists, FRP was detectable in 60%, 87% and 73% of the participants in TES, LES and Gluteus max, respectively, and happened between 74% and 82% of the trunk flexion. There was no statistically significant difference in onset and offset of muscles FRP. Despite prolong hyper kyphotic posture, FRP was identifiable in TES, LES and Gluteus max muscles of elite cyclists.

Effect of a semi-rigid backpack type thoracolumbar orthosis on thoracic kyphosis angle and muscle performance in older adults with hyperkyphosis: a randomized controlled trial

PURPOSE

To investigate the effect of a semi-rigid backpack type thoracolumbar orthosis (TLO) on thoracic kyphosis angle (TKA) and potentially contributing factors of hyperkyphosis, including position sense and back muscle strength and endurance.

METHOD

This randomized, controlled trial was conducted on 48 older adults with hyperkyphosis, randomly allocated to an experimental or control group. The experimental group wore a semi-rigid TLO for 3 consecutive months. The control group received no external support or exercise. Thoracic kyphosis angle (TKA), joint position sense, back muscle strength and endurance were evaluated at the baseline and at the end of week 6 and week 12.

RESULTS

The two-way (group × time) interactions were significant in terms of TKA (F = 37.88, p ≤ 0.001, η_p² = 0.45), muscle strength (F = 26.005, p ≤ 0.001, η_p² = 0.36), muscle endurance measured via load cell (F = 3.417, p = 0.039, η_p² = 0.06), and endurance holding time of Ito test (F = 3.629, p = 0.045, η_p² = 0.07). A further analysis using one-way repeated measures of ANOVA showed that TKA, muscle strength and endurance were significantly improved in the experimental group. Also, two-way interactions were significant for absolute error and variable error of trunk neutral repositioning test from a trunk flexed and/or extended position for global components and horizontal components trunk repositioning test.

CONCLUSION

Wearing a semi-rigid backpack type TLO even from an unknown brand for short periods during the day (e.g., 2-4 h) over 3 months not only modifies kyphotic posture but also can enhance back muscle performance in older adults with hyperkyphosis. IMPLICATIONS FOR REHABILITATIONPrescription of a semi-rigid backpack type thoracolumbar orthosis for older adults has no adverse effects such as muscle weakness if it is applied for short periods during the day.A semi-rigid backpack thoracolumbar orthosis can prevent position sense degradation in older adults with hyperkyphosis.A semi-rigid backpack type thoracolumbar orthosis may counteract trunk flexion and kyphotic posture by applying the biomechanical principles of the three-point pressure system.Improvement in spinal alignment resulting from wearing thoracolumbar orthosis should not occur in exchange for muscle deconditioning.

Test-retest reliability of a load cell setup, Ito, and timed loaded standing tests for measuring muscle strength and endurance in older adults with and without hyperkyphosis

BACKGROUND

The association of back muscle weakness with greater thoracic kyphosis has been widely documented. Reliable and easy-to-use techniques are needed to monitor changes in muscle function over time and assess the effectiveness of therapeutic interventions. Therefore, the present study aimed to evaluate the test-retest reliability of a designed load-cell setup and two clinical tests, namely Ito and Timed loaded standing (TLS) tests for measuring back muscle function (i.e., strength and endurance) in older adults with and without hyperkyphosis.

METHOD

Fifty-three older people (28 with thoracic hyperkyphosis and 25 normal age-matched controls) completed the present test-retest reliability study. A two-way random model of the Intraclass Correlation Coefficient (ICC_2,3) was used to estimate relative reliability. Absolute reliability was assessed by calculating Standard Error of the Measurements (SEM) and Minimal Detectable Change (MDC).

RESULTS

The findings showed excellent test-retest reliability in all performed tests for this population (ICC = 0.95-0.99). In addition, the MDC values for measuring endurance time via load cell, Ito, and TLS tests in the hyperkyphosis group, were 16.5, 28.2, and 35.1 s, respectively. These values ranged from 36 to 39 s for the control group.

CONCLUSION

The present study suggests high test-retest reliability of the designed load-cell setup, Ito, and TLS for assessing back extensor muscle strength and endurance in older adults with and or without hyperkyphosis.

The relationship between thoracic posture and ultrasound echo intensity of muscles spanning this region in healthy men and women

PURPOSE

Skeletal muscle echogenicity intensity (EI) is considered a measure of muscle quality, being associated with old age and pathologies. Whether EI variations can be identified in healthy adults, due to habitual shortened or elongated muscle position is unknown. Thus, this study aimed to assess the relationship between thoracic kyphosis angulation and EI scores of muscles spanning this region ((Lower Trapezius (LT), Rhomboid Major (RM), Erector Spine (ES)) in healthy young people and in addition to examine the relationship between the change in thoracic kyphosis angle from relaxed to upright position (∆°) and the EI of these muscles.

METHODS

Thoracic kyphosis in relaxed and erect standing was measured using a digital inclinometer in 29 healthy adults (16 women, 13 men), aged 25-35 years. The thoracic kyphosis angles including the difference between relaxed and erect postures (∆°) were correlated to the EI scores of right and left LT, RM and ES.

RESULTS

No significant differences in EI were found between the 3 muscles EI or between sides, hence they were pooled together to a total thoracic EI score (TTEI). Although the TTEI did not correlate with relaxed or erect thoracic kyphosis, it was significantly but negatively correlated with ∆° in the entire group: Pearson's correlation coefficient of r = -0.544; p = .01 and in men; r = -0.732; p = .01, failing to reach significance in women; r = -0.457.

CONCLUSION

The negative association between the EI of the explored muscles and ∆° could imply a possible relationship between these muscles range of movement excursions and their composition.

The association between physical function and hyperkyphosis in older females: Protocol for a systematic review

Identifying factors that impact physical function in older populations is important for the maintenance of good health with aging. Age-related hyperkyphosis, an excessive curvature in the thoracic spine, affects up to 40% of the older adults and is more common in older females than males. An association of age-related hyperkyphosis with impaired physical function has been reported in numerous studies, however, other studies have reported that a greater magnitude of kyphosis did not associate with impaired physical function. Given the inconsistencies regarding the impact of hyperkyphosis on physical function, the purpose of our study is to perform a systematic review of the existing studies in order to better describe the association between hyperkyphosis and physical function. Prospective and retrospective cohort, case-control, and cross-sectional studies which measure physical function by valid functional tests and questionnaires in older females will be included. We will search Scopus, ISI Web of Science, Cochrane Library, PubMed, Cumulative Index to Nursing and Allied Health Literature (CINAHL) and PEDro databases. Studies will be searched and then selected by two independent reviewers based on quality assessment tools from the National Heart, Lung, and Blood Institute (NHLBI). A meta-analysis will be conducted if data reported for individual studies allow. Specifically, if two or more individual studies provide measures of central tendency and variability from any of the categories of physical function measures, data will be gathered for meta-analysis. If a meta-analysis is not possible, data will be synthesized and described in a narrative form by size and variability of effect, direction of effect, and association with hyperkyphosis.

Thoracic and Lumbar Sagittal Spinal Curvature Adaptations between Elite Iranian Road and Speed Cyclists

Background:

Despite existing some research on the effects of professional cycling on cyclist’s spinal curvature angles, no research is available concentrating on possible differences in various types of professional cycling. Road (outdoor) and speed (indoor) cyclists have different anthropometric and predominant postures during cycling. The current study aims to investigate if cyclists with different types of cycling may have dissimilar spinal curvature adaptations.

Objective:

Forty-eight male subjects, including 16 elite road cyclists, 16 elite sprint cyclists and 16 non-athletes as the control group were recruited in this non-experimental study.

Material and Methods:

In this cross-sectional study, a spinal mouse was used to measure the thoracic and lumbar curvature angles in standing position.

Results:

The mean values of thoracic kyphosis and lumbar lordosis angles were found as follows 48.3±7.2º & -20.3±7.2º for elite road cyclists; 46.6±8.1º & -22.5±7.7º for elite sprint cyclists; and 37.5±4.1º & -19±6.3º for the control group. The results confirmed that both the road and sprint cyclists showed significantly more hyper-kyphosis posture in their thoracic region when compared to the control group (p<0.05).

Conclusion:

All road cyclists showed no significantly higher degrees of thoracic angle relative to the sprint cyclists (p>0.05). However, all the cyclists and the control groups showed a normal range of lumbar lordosis angle. As a conclusion, the results of this study confirmed that an elite cyclist may predispose these subjects to the risk of hyper-kyphotic posture. The road cycling may result in more hyper-kyphosis due to the longer time, spent in flexed position.