The feasibility of measuring the activation of the trunk muscles in healthy older adults during trunk stability exercises

An Investigation of the Association between Transversus Abdominis Myofascial Structure and Activation with Age in Healthy Adults using Ultrasound Imaging

BACKGROUND

Because of their importance in core stability, training the deep abdominal muscles, fascial structures and particularly the transversus abdominis, is a key component of many sport and physical therapy programs. However, there are gaps in knowledge about age-related changes in the structure and activation capacity of these muscles.

HYPOTHESIS/PURPOSE

This study investigated the association between deep abdominal muscles and fascial structures and transversus abdominis activation with age in healthy adults.

STUDY DESIGN

A cross-sectional study.

METHODS

Eighty-six adults aged 18 to 77 participated in this study. An ultrasound image of their transversus abdominis, internal oblique, external oblique and associated fasciae was first captured at rest, then during a contraction of the transversus abdominis. Bivariate correlation analyses and hierarchical analyses were performed (significance level: p < 0.05).

RESULTS

The thickness of these three muscles decreases with age ( ρ = -0.66 for external oblique, -0.51 for internal oblique and -0.58 for transversus abdominis), whereas the thickness of their fasciae increases ( ρ = 0.39 for the fascia of external oblique, 0.54 for the fascia between internal oblique and external oblique, and 0.74 for the fascia between internal oblique and transversus abdominis). Transversus abdominis activation decreases with age (r =-0.44). Age accounts for 19.5% of the variance in transversus abdominis activation.

CONCLUSION

These results demonstrate that normal aging is associated with changes in deep abdominal myofascial structures and transversus abdominis activation. Assessment of these metrics can provide valuable baseline information for physical therapists involved in rehabilitation and strengthening programs targeting older individuals.

LEVEL OF EVIDENCE

Level 2.

Reliability and Validity of a New Method for Isometric Back Extensor Strength Evaluation Using A Hand-Held Dynamometer

Objective

To investigate the reliability and validity of a new method for isometric back extensor strength measurement using a portable dynamometer.

Methods

A chair equipped with a small portable dynamometer was designed (Power Track II Commander Muscle Tester). A total of 15 men (mean age, 34.8±7.5 years) and 15 women (mean age, 33.1±5.5 years) with no current back problems or previous history of back surgery were recruited. Subjects were asked to push the back of the chair while seated, and their isometric back extensor strength was measured by the portable dynamometer. Test-retest reliability was assessed with intraclass correlation coefficient (ICC). For the validity assessment, isometric back extensor strength of all subjects was measured by a widely used physical performance evaluation instrument, BTE PrimusRS system. The limit of agreement (LoA) from the Bland-Altman plot was evaluated between two methods.

Results

The test-retest reliability was excellent (ICC=0.82; 95% confidence interval, 0.65–0.91). The Bland-Altman plots demonstrated acceptable agreement between the two methods: the lower 95% LoA was −63.1 N and the upper 95% LoA was 61.1 N.

Conclusion

This study shows that isometric back extensor strength measurement using a portable dynamometer has good reliability and validity.

The assessment of abdominal and multifidus muscles and their role in physical function in older adults: a systematic review

BACKGROUND

Age-related changes in the trunk (abdominal and lumbar multifidus) muscles and their impact on physical function of older adults are not clearly understood.

OBJECTIVES

To systematically summarise studies of these trunk muscles in older adults.

DATA SOURCES

Cochrane Library, Pubmed, EMBASE and CINAHL were searched using terms for abdominal and MF muscles and measurement methods.

STUDY SELECTION

Two reviewers independently assessed studies and included those reporting measurements of abdominal muscles and/or MF by ultrasound, computed tomography, magnetic resonance imaging or electromyography of adults aged ≥50 years.

DATA SYNTHESIS

A best evidence synthesis was performed.

RESULTS

Best evidence synthesis revealed limited evidence for detrimental effects of ageing or spinal conditions on trunk muscles, and conflicting evidence for decreased physical activity or stroke having detrimental effects on trunk muscles. Thicknesses of rectus abdominis, internal oblique and external oblique muscles were 36% to 48% smaller for older than younger adults. Muscle quality was poorer among people with moderate-extreme low back pain and predicted physical function outcomes.

LIMITATIONS

Study heterogeneity precluded meta-analysis.

CONCLUSION

Overall, the evidence base in older people has significant limitations, so the role of physiotherapy interventions aimed at these muscles remains unclear. The results point to areas in which further research could lead to clinically useful outcomes. These include determining the role of the trunk muscles in the physical function of older adults and disease; developing and testing rehabilitation programmes for older people with spinal conditions and lower back pain; and identifying modifiable factors that could mitigate age-related changes.

The influences of position and forced respiratory maneuvers on spinal stability muscles

[Purpose] The purposes of this study were to investigate the influences of position on %MVIC of spinal stability muscles to establish for the most effective breathing pattern for activation of spinal stability muscles in order to provide an additional treatment method for use in spinal stability exercise programs. [Subjects and Methods] Thirty-three healthy subjects performed quiet breathing and four different forced respiratory maneuvers (FRM); [pursed lip breathing (PLB), diaphragmatic breathing (DB), combination breathing (CB) and respiration muscle endurance training (RMET)] in both standing and sitting positions. %MVIC of them (the multifidus (MF), erector spinae (ES), internal oblique/transversus abdominis (IO/TrA), external oblique (EO), rectus abdominis (RA) measured. [Results] IO/TrA, MF and EO showed greater activation in standing than in sitting, while RA and ES showed greater activation in sitting than in standing. RMET induced significantly greater activation of spinal stability muscles then other breathing patterns. %MVIC changes of muscle activities induced by FRM were independent of position with a few exceptions. [Conclusion] The increased respiratory demands of FRM induced greater activation of spinal stability muscles than QB. RMET was found to be the most effective breathing pattern for increasing the activation of the spinal stability muscles.

The Neural Control of Spinal Stability Muscles during Different Respiratory Patterns

[Purpose] It is well-known that the muscles of spinal stability also play roles in respiration. The spinal stability muscles are divided into two subgroups, the local muscle group and the global muscle group. Appropriately coordinated activation of muscle groups are recommended for more efficient spinal stability. The indirect method of measuring coordination of muscle groups is the synergist ratio of local muscles to global muscles. The purpose of this study was to investigate the synergist ratios of the spinal stability muscles of different breathing patterns. [Subjects and Methods] Forty healthy subjects performed 4 different breathing patterns and 3 synergist ratios calculated from % maximal voluntary isometric contraction of 2 local group muscles and 3 global group muscles were analyzed. [Results] The results of this study show synergist ratios were consistent among the breathing patterns and there was a consistent muscle reliance pattern of synergist ratios during each breathing pattern. The synergist ratio of extensors stayed around 1. The results were consistent with those of previous studies of spinal stability exercises. [Conclusion] We suggest that different breathing patterns could be used as a component of spinal stability exercises, secondary to the similarities of muscle coordination with spinal stability exercises, commonly used in clinics.

Eletroestimulação e core training sobre dor e arco de movimento na lombalgia

INTRODUÇÃO: Eletrotermofototerapia e cinesioterapia são opções para o tratamento de lombalgias. Exercícios voltados para a musculatura paravertebral visam ao aumento de força e arco de movimento (ADM). A eletroestimulação neuromuscular (EENM) incrementa a função muscular. OBJETIVOS: Apurar a influência da EENM associada a um programa de core training (CT) sobre a lombalgia inespecífica crônica, com as variáveis de dor e ADM da coluna vertebral. MATERIAIS E MÉTODOS: Foi realizado ensaio clínico controlado randomizado duplo cego, com 27 pacientes atendidos na Clínica-Escola FIT-UGF, com diagnóstico médico relacionado a lombalgias. Foram formados dois grupos aleatoriamente: controle ativo (CORE; n = 13) e experimental (CORE + EENM; n = 14). O questionário de McGill e a fotogrametria foram aplicados antes da primeira e após a última sessão de tratamentos para medir dor e ADM, respectivamente. RESULTADOS: Os grupos eram homogêneos quanto à dor inicial (p = 0,99); a dor final do grupo CORE + EENM foi significativamente menor que a do grupo CORE (p = 0,03); a dor final do grupo CORE não apresentou diferença significativa em relação à inicial (p = 0,93); a dor final do grupo CORE + EENM foi significativamente menor que a inicial (p = 0,00). O ADM não apresentou diferença significativa intragrupos e intergrupos (p = 0,10). CONCLUSÃO: A aplicação de EENM em região lombar após CT foi eficaz, causando diminuição significativa da lombalgia inespecífica. Entretanto, não ocorreu diferença significativa do ADM entre os grupos.

A comparison of trunk muscle activation amplitudes during gait in older adults with and without chronic low back pain

OBJECTIVE

To investigate abdominal and low back muscle activation amplitudes of older adults (at least 50 years of age) experiencing nonspecific chronic low back pain (LBP) and of adults without LBP while they walked on a level surface at a self-selected speed.

DESIGN

Cross-sectional.

SETTING

Dynamics of human motion laboratory.

PARTICIPANTS

Nine asymptomatic control participants (mean ± standard deviation: 64.9 ± 8.8 years) and 9 participants experiencing LBP (61.4 ± 9.8 years) were selected for this study.

METHODS

Surface electromyography (EMG) was recorded over the bilateral lower rectus abdomini, internal obliques, lateral erector spinae longissimus, and lumbar multifidus muscle sites while participants walked across a pressure-sensor mat at a self-selected speed. To normalize EMG amplitudes during gait, the participants performed a series of maximal voluntary isometric contractions. EMG signals were full-wave rectified and low-pass filtered to yield a linear envelop waveform. For the gait trials, a window was identified from right heel strike to the second left heel strike and 4 subphases, including right and left loading response and mid stance, were identified. EMG amplitudes were calculated for each subphase.

MAIN OUTCOME MEASUREMENTS

Two sample t-tests compared demographic information and spatiotemporal gait parameters between groups. EMG activation amplitude differences between groups and among subphases of gait were analyzed for each muscle with use of general linear models, followed by Tukey honestly significant difference post hoc comparisons.

RESULTS

No differences were found between the groups for demographic or gait parameters. The control group participants activated their lower rectus abdomini muscles (P < .05) and right internal oblique muscles significantly more than did the LBP group (P < .05), whereas the LBP group activated their left lateral erector spinae and both lumbar multifidi sites significantly more than did the control group (P < .05).

CONCLUSIONS

The activation amplitudes of the anterior muscle sites were lower for participants with LBP, whereas the posterior sites were activated to higher amplitudes than in the control group. Although most muscles responded to the subphases indicating muscle synergies, the group by muscle interactions for the right internal oblique and lateral erector spinae show that the differences between groups were not systematic. These results describe neuromuscular alterations in persons between 50-80 years with LBP that can be used for developing subject-specific management related to maintaining spinal stability.