Elderly oarsmen have larger trunk and thigh muscles and greater strength than age-matched untrained men

The combined effect of rowing exercise and the intake of functional foods containing inulin on muscle mass and bone mineral density in older Japanese women

AIM

Aging decreases muscle mass and bone mineral density (BMD), especially in older women. It has been reported that rowing and inulin intake positively affect muscle and bone, respectively. We examined the synergistic effect of rowing and functional food intake, including inulin, on lean body mass, BMD, and physical function parameters in older Japanese women.

METHODS

Fifty women aged 65-79 years were divided into four groups with or without inulin intake and rowing. The interventions were carried out for 12 weeks in each group. We assessed lean body mass and BMD using dual-energy X-ray absorptiometry at baseline and after the intervention and examined the changes in the values in each group.

RESULTS

Lean body mass in all groups decreased, and the change in lean body mass in the group with rowing and inulin intake was significantly smaller than that in the group without them (-0.05 ± 0.61; -0.83 ± 0.59 kg; P = 0.030). The BMD in the three intervention groups increased after the 12-week intervention. The change in BMD in each of the three intervention groups showed significant differences compared with the control group (Rowing + Inulin: P = 0.03; Rowing + No inulin: P = 0.01; No rowing + Inulin: P < 0.01).

CONCLUSIONS

Rowing and the intake of functional foods, including inulin, synergistically prevented a decrease in lean body mass. These factors, individually and additively, might increase BMD in older Japanese women. Geriatr Gerontol Int 2023; 23: 779-787.

Comparison of erector spinae fatigability between female patients with Parkinson's disease and healthy individuals: a cross sectional pilot study

BACKGROUND

Postural abnormality is one of the main symptoms of Parkinson's disease (PD). The erector spinae muscles play an important role in maintaining an upright posture, but the fatigability of the erector spinae in patients with PD is unknown. The purpose of this study was to compare the trunk extension maximum voluntary contraction (MVC) and the fatigability of the erector spinae between female patients with PD and healthy volunteers.

METHODS

Th participants of this cross-sectional pilot study comprised 19 patients with PD and nine healthy volunteers matched for sex, age, and physical characteristics as a control group. The MVC of all participants was measured, and after sufficient rest, the Sørensen back endurance test was conducted to the point of exhaustion. The muscle activity of the erector spinae during the Sørensen back endurance test was measured using surface electromyography. The median frequency (MF) slope, which is an index of fatigability, was calculated from the recorded surface muscle activity by means of power spectrum analysis using a Fast Fourier transformation.

RESULTS

Nine of the 19 patients with PD were unable to perform the Sørensen back endurance test, and a lower proportion of the PD group were able to perform it compared with the control group. The MVC of those patients with PD who were able to perform the Sørensen back endurance test was lower than that of the control group, and the time for which the pose could be maintained was shorter. There was no significant difference between the MF slope on the left and right side in the PD group, and it was higher on both sides than in the control group.

CONCLUSION

This is the first study to demonstrate a reduction of maximum muscle strength and great fatigability of the erector spinae in patients with PD. This discovery strongly underlines the need for paraspinal muscle training from an early stage with the aim of preventing the progression of postural abnormality in patients with PD.

Training-Induced Muscle Adaptations During Competitive Preparation in Elite Female Rowers

Training-induced adaptations in muscle morphology, including their magnitude and individual variation, remain relatively unknown in elite athletes. We reported changes in rowing performance and muscle morphology during the general and competitive preparation phases in elite rowers. Nineteen female rowers completed 8 weeks of general preparation, including concurrent endurance and high-load resistance training (HLRT). Seven rowers were monitored during a subsequent 16 weeks of competitive preparation, including concurrent endurance and resistance training with additional plyometric loading (APL). Vastus lateralis muscle volume, physiological cross-sectional area (PCSA), fascicle length, and pennation angle were measured using 3D ultrasonography. Rowing ergometer power output was measured as mean power in the final 4 minutes of an incremental test. Rowing ergometer power output improved during general preparation [+2 ± 2%, effect size (ES) = 0.22, P = 0.004], while fascicle length decreased (−5 ± 8%, ES = −0.47, P = 0.020). Rowing power output further improved during competitive preparation (+5 ± 3%, ES = 0.52, P = 0.010). Here, morphological adaptations were not significant, but demonstrated large ESs for fascicle length (+13 ± 19%, ES = 0.93), medium for pennation angle (−9 ± 15%, ES = −0.71), and small for muscle volume (+8 ± 13%, ES = 0.32). Importantly, rowers showed large individual differences in their training-induced muscle adaptations. In conclusion, vastus lateralis muscles of elite female athletes are highly adaptive to specific training stimuli, and adaptations largely differ between individual athletes. Therefore, coaches are encouraged to closely monitor their athletes' individual (muscle) adaptations to better evaluate the effectiveness of their training programs and finetune them to the athlete's individual needs.

The physiology of rowing with perspective on training and health

PURPOSE

This review presents a perspective on the expansive literature on rowing.

METHODS

The PubMed database was searched for the most relevant literature, while some information was obtained from books.

RESULTS

Following the life span of former rowers paved the way to advocate exercise for health promotion. Rowing involves almost all muscles during the stroke and competition requires a large oxygen uptake, which is challenged by the pulmonary diffusion capacity and restriction in blood flow to the muscles. Unique training adaptations allow for simultaneous engagement of the legs in the relatively slow movement of the rowing stroke that, therefore, involves primarily slow-twitch muscle fibres. Like other sport activities, rowing is associated with adaptation not only of the heart, including both increased internal diameters and myocardial size, but also skeletal muscles with hypertrophy of especially slow-twitch muscle fibres. The high metabolic requirement of intense rowing reduces blood pH and, thereby, arterial oxygen saturation decreases as arterial oxygen tension becomes affected.

CONCLUSION

Competitive rowing challenges most systems in the body including pulmonary function and circulatory control with implication for cerebral blood flow and neuromuscular activation. Thus, the physiology of rowing is complex, but it obviously favours large individuals with arms and legs that allow the development of a long stroke. Present inquiries include the development of an appropriately large cardiac output despite the Valsalva-like manoeuvre associated with the stroke, and the remarkable ability of the brain to maintain motor control and metabolism despite marked reductions in cerebral blood flow and oxygenation.

Applicability of ultrasonography for evaluating trunk muscles size in athletes: a study focused on baseball batters

[Purpose] Recently, we demonstrated that the thicknesses of trunk muscles measured using ultrasonography were correlated strongly with the cross-sectional areas measured using magnetic resonance imaging in untrained subjects. To further explore the applicability of ultrasonography in the clinical setting, the present study examined the correlation between ultrasonography-measured thicknesses and magnetic resonance imaging-measured cross-sectional areas of trunk muscles in athletes with trained trunk muscles. [Subjects and Methods] The thicknesses and cross-sectional areas at total 10 sites of the bilateral sides of the upper, central, and lower parts of the rectus abdominis, abdominal wall, and multifidus lumborum in 30 male baseball batters were measured. [Results] Overall thicknesses and cross-sectional areas of the trunk muscles in baseball batters were higher than those in untrained subjects who participated in our previous study. The ultrasonography-measured thicknesses at all 10 sites of the trunk muscles correlated highly with the magnetic resonance imaging-measured cross-sectional areas in baseball batters. [Conclusion] These results suggest that the thicknesses of the trunk muscles measured using ultrasonography can be used as a surrogate marker for the cross-sectional area measured using magnetic resonance imaging, in athletes who have larger trunk muscles than that of untrained subjects.

Associations between trunk muscle morphology, strength and function in older adults

Skeletal muscle plays an important role in performing activities of daily living. While the importance of limb musculature in performing these tasks is well established, less research has focused on the muscles of the trunk. The purpose of the current study therefore, was to examine the associations between functional ability and trunk musculature in sixty-four community living males and females aged 60 years and older. Univariate and multivariate analyses of the a priori hypotheses were performed and reported with correlation coefficients and unstandardized beta coefficients (β) respectively. The univariate analysis revealed significant correlations between trunk muscle size and functional ability (rectus abdominis: six-minute walk performance, chair stand test, sitting and rising test; lumbar multifidus: timed up and go) as well as trunk muscle strength and functional ability (trunk composite strength: six-minute walk performance, chair stand test, Berg balance performance, sitting and rising test). After controlling for covariates (age and BMI) in the multivariate analysis, higher composite trunk strength (β = 0.34) and rectus abdominis size (β = 0.33) were associated with better performance in the sitting and rising test. The importance of incorporating trunk muscle training into programs aimed at improving balance and mobility in older adults merits further exploration.

Effect of knee alignment on the quadriceps femoris muscularity: Cross-sectional comparison of trained versus untrained individuals in both sexes

Knee alignment is suggested to be a factor affecting each quadriceps femoris muscle size, and knee alignment such as Q-angle differs between men and women. Also, training can induce inhomogeneous hypertrophy among the quadriceps femoris, thereby leading to different component characteristics of the muscles. If Q-angle is a major determinant of the quadriceps femoris muscularity, it is hypothesized that the sex-related difference in the quadriceps femoris muscularity, if any, is further highlighted in trained individuals, being associated with Q-angle. We tested this hypothesis. Magnetic resonance images of the right thigh were obtained from 26 varsity rowers as trained subjects (13 for each sex) and 34 untrained individuals as controls (17 for each sex). From the images, muscle volume of each constituent of the quadriceps femoris (vastus lateralis, VL; medialis, VM; intermedius; rectus femoris) was determined. The Q-angle was measured during quiet bilateral standing with hand support as needed. Percent volume of VM to the total quadriceps femoris was greater in female rowers than male rowers and female controls, and that of VL was greater in male rowers than male controls. There were no correlations between Q-angle and percent muscle volume in any muscles regardless of rowing experience or sex. The current study revealed that well-trained rowers have sex-related quadriceps femoris muscularity but no significant correlations between percent muscle volume in any muscles and Q-angle. Our findings suggest that Q-angle is not a major determinant of the quadriceps femoris muscularity in either well-trained or untrained individuals.

Bone mass and bone metabolic indices in male master rowers

The purpose of this study was to assess bone mass and bone metabolic indices in master athletes who regularly perform rowing exercises. The study was performed in 29 men: 14 master rowers and 15 non-athletic, body mass index-matched controls. Dual-energy X-ray absorptiometry measurements of the areal bone mineral density (aBMD) were performed for the total body, regional areas (arms, total forearms, trunk, thoracic spine, pelvis, and legs), lumbar spine (L1-L4), left hip (total hip and femoral neck), and forearm (33 % radius of the dominant and nondominant forearm). Serum concentrations of osteocalcin, collagen type I cross-linked C-telopeptide, visfatin, resistin, insulin, and glucose were determined. Comparative analyses showed significantly lower levels of body fat and higher lean body mass values in the rowers compared to the control group. The rowers also had significantly higher values of total and regional (left arm, trunk, thoracic spine, pelvis, and leg) BMD, as well as higher BMD values for the lumbar spine and the left hip. There were significant differences between the groups with respect to insulin, glucose, and the index of homeostasis model assessment insulin resistance. In conclusion, the systematic training of master rowers has beneficial effects on total and regional BMD and may be recommended for preventing osteoporosis.

MRI-determined lumbar muscle morphometry in man and sheep: potential biomechanical implications for ovine model to human spine translation

The sheep is a commonly used animal model for human lumbar spine surgery, but only in vitro investigations comparing the human and ovine spine exist. Spinal musculature has previously not been compared between man and sheep. This additional knowledge could further indicate to what extent these species are biomechanically similar. Therefore, the purpose of the study was to investigate spinal muscle morphometric properties using magnetic resonance imaging (MRI) in different age groups of healthy human participants and sheep in vivo. Healthy human participants (n = 24) and sheep (n = 17) of different age groups underwent T1-weighted MRI of the lumbar spine. Regions of interest of the muscles erector spinae (ES), multifidus (M) and psoas (PS) were identified. The ratio of flexor to extensor volume, ratio of M to ES volume, and muscle fat relative to an area of intermuscular fat were calculated. Sheep M to ES ratio was significantly smaller than in the human participants (sheep 0.16 ± 0.02; human 0.37 ± 0.05; P < 0.001), although flexor to extensor ratio was not significantly different between species (human 0.39 ± 0.08; sheep 0.43 ± 0.05; P = 0.06). Age did not influence any muscle ratio outcome. Sheep had significantly greater extensor muscle fat compared with the human participants (M left human 40.64%, sheep 53.81%; M right human 39.17%, sheep 51.33%; ES left human 40.86%, sheep 51.29%; ES right human 35.93%, sheep 44.38%; all median values; all P < 0.001), although PS did not show any significant between-species differences (PS left human 36.89%, sheep 33.67%; PS right human 32.78%, sheep 30.09%; P < 0.05). The apparent differences in the size and shape of sheep and human lumbar spine muscles may indicate dissimilar biomechanical and functional demands, which is an important consideration when translating to human surgical models.

Inter-rater reliability of trunk muscle morphometric analysis

BACKGROUND

Inter-rater reliability of generalised lumbar extensor muscle CSA has been identified, however, more detailed reliability metrics of individual trunk muscles are lacking.

OBJECTIVE

To report muscle volume and muscle fatty infiltrate (MFI) inter-rater reliability of individual trunk muscles between two novice assessors.

METHODS

Lumbar axial MRI scans from 10 healthy male participants were analysed. The muscles erector spinae (ES), multifidus (M), rectus abdominis (RA), and psoas (PS) were manually traced, region of interest quantified and muscle volume and MFI determined by both assessors. Agreement between the assessors was determined using intraclass correlation coefficients (3,1), Bland-Altman plots and Lin's concordance coefficient.

RESULTS

Good to excellent agreement was found for volume (ICC 0.77-0.96) and MFI (0.84-0.96) for all muscles on first evaluation, except for M volume, which required a second evaluation. Best agreement for muscle volume and MFI was found for ES (ICC 0.96).

CONCLUSIONS

First evaluation of muscle volume and MFI yields high to excellent inter-rater agreement, except for M, where further training and/or experience is required to achieve acceptable reliability outcomes. This may have clinical implications due to the relevance of M atrophy reported in patients with low back pain.

Age and side-related morphometric MRI evaluation of trunk muscles in people without back pain

This study evaluated lumbar spine muscle volume and Muscle Fatty Infiltrate (MFI) across two age groups of healthy adults. Twenty-four participants (young group - YG: age 18-25, n = 12; mature group - MG: age 45-60, n = 12) without low back pain underwent T1-weighted axial MRI. Muscle volume and MFI were obtained from the left and right lumbar erector spinae (ES), multifidus (M), rectus abdominis (RA) and psoas (PS) muscles. For MFI, mean pixel intensity (MPI) of muscles was reported as a percentage of subcutaneous fat MPI. Within-group comparison of left and right side muscle volume was not significantly different in the YG. In the MG, right RA and ES were significantly smaller than left (RA p = 0.049; ES p = 0.03). In both groups, left PS, M and ES MFI was significantly smaller compared to the right side and left RA MFI was significantly greater compared to right side (all p ≤ 0.001). For M volume, 81.7-84.6% of variance was explained by age, height and Body Mass Index (BMI). For ES volume, 81.6-82.8% of variance was explained by height and BMI. Age explained 18.1%-36.0% of variance in M and ES right MFI. Therefore, age and BMI are relevant factors for extensor muscle volume, but not for flexor muscle volume. Also, age significantly influences MFI for right-sided extensors only. The age effect is apparently independent of full subjective back functionality. For future spinal muscle research, the side-and muscle-specific effect of age on muscle morphology should be considered.