Effect of controlled start position on the reach distance distribution range in the functional reach test among community-dwelling older adults.

[Purpose] This study investigated the effect of controlled start position (CSP) on the reach distance distribution range (RDDR) in the functional reach test (FRT) in community-dwelling older adults. [Participants and Methods] The participants were 34 community-dwelling older adults. We compared the RDDR in CSP and non-CSP and analyzed the relationship between the mean reach distance (MRD) and the length of movement of the center of pressure (LMCOP). [Results] The RDDR in CSP condition was significantly lower than non-CSP condition. A significant positive correlation was observed only for CSP condition. In the non-CSP condition, MRD was not reflected in the LMCOP. [Conclusion] The FRT in the CSP effectively reflects the standing balance ability of community-dwelling older adults.

Development of Connective Tissue Area Increases by Initial Impact With High-Intensity Exercise After Reloading in Rat Soleus Muscle.

OBJECTIVE: The aim of the study is to clarify whether high-intensity exercise in atrophied skeletal muscle after reloading (1) increases the injury and promotes the development of the muscle connective tissue area in the soleus muscle and (2) delays muscle strength recovery. DESIGN: Rats had their hindlimbs suspended for 14 days followed by hindlimb reloading and squat exercise of 30% or 70%-one-repetition maximum exercise until 14 days of reloading. The influences of reloading and exercise in muscles were examined by histological and immunofluorescence analyses based on the exercise load. RESULTS: Seventy percent-one-repetition maximum exercise increased the extramyofiber area more than the control group and the central nuclear fiber number than the other groups after 7 days of reloading. Seventy percent-one-repetition maximum exercise resulted in a larger muscle connective tissue area than the control and reload groups after 14 days of reloading. Myogenin and M2-type macrophages after 7 days of reloading increased by reloading but were not increased by the exercise load. CONCLUSIONS: Seventy percent-one-repetition maximum exercise to atrophied muscle increased injury early in postreloading and increased the muscle connective tissue area after 14 days of reloading, but evidence that it delays muscle strength recovery was lacking. Therefore, muscle connective tissue area induced by high-intensity exercise after reloading seems to be associated with initial exercise damage but not with repetition over 14 days.

Association Between Nondominant Leg-Side Hip Internal Rotation Restriction and Low Back Pain in Male Elite High School Soft Tennis Players.

CONTEXT: The incidence of low back pain (LBP) is high among high school male soft tennis players. In some sports for which the rotational component of the body is important, an association between restricted hip internal rotation of the nondominant leg and LBP has been reported; however, whether this association holds in soft tennis is unknown. Therefore, this study aimed to evaluate the association between hip internal rotation, hip external rotation, hamstring flexibility, iliopsoas flexibility, and LBP incidence. DESIGN: This study was designed as a cross-sectional study, conducted at a sports training center. METHODS: Participants comprised 113 male elite high school soft tennis players (age: 16.1 [0.7] y) from 9 elite-level teams. The main outcome measures were the hip internal and external rotation range of motion, hamstring flexibility on the straight leg raise test, and iliopsoas flexibility on the Thomas test. Multiple logistic regression analysis was performed to examine the influence of main outcomes on LBP incidence in the past 1 year. RESULTS: A total of 35 participants had LBP (LBP group); 78 participants did not have LBP (non-LBP group). Multiple logistic regression analysis revealed that the odds ratio for height was 1.08 (95% confidence interval, 1.00-1.16; P = .043) and for the hip internal rotation range of motion in the nondominant leg was 0.90 (95% confidence interval, 0.85-0.95; P < .001), indicating significant associations with LBP. CONCLUSION: Hip internal rotation range of motion in the nondominant leg and height were crucial factors related to LBP in male elite high school soft tennis players.

Effect of a controlled starting position on the relationship between the forward reach distance and movement distance of the center of pressure in the functional reach test using the ankle joint strategy.

[Purpose] This study aimed to clarify whether the distribution range of the forward reach distance and the relationship between the forward reach distance and the movement distance of the center of pressure differed depending on whether the controlled starting standing position during the functional reach test with an ankle joint strategy. [Participants and Methods] Sixteen healthy male volunteers participated in the study. The distribution range of the forward reach distance and the relationship between the forward reach distance and movement distance of the center of pressure in the controlled starting standing position and non-controlled starting standing position conditions were analyzed. [Results] The distribution range of the forward reach distance was significantly smaller in the controlled starting standing position than in the non-controlled starting standing position. In both groups, the forward reach distance was associated with the movement distance of the center of pressure. [Conclusion] The findings suggested that the use of an ankle joint strategy with a controlled starting standing position in the functional reach test may be a more accurate method to evaluate standing balance ability.

Inflammatory myopathies overlapping with systemic sclerosis: a systematic review.

We performed a systematic review of the clinical manifestations and complementary exams of patients with myopathies and systemic sclerosis overlap syndrome (MyoSScOS). Systematic review from January 1976 to November 2021 according PRISMA protocol on three electronic databases: PubMed, Web of Science, and Scopus. Studies were analyzed based on the following eligibility criteria: at least one combination of the terms described in the search strategy appears in the title; written in English, Portuguese, or Spanish; and addresses MyoSScOS. Brief communications, reviews, studies that addressed myopathies in children, congress proceedings, monographs, and dissertations were excluded. Thirty-five articles were selected. MyoSScOS seems to be more common in women. It also commonly affects the esophagus and joints with symmetrical and bilateral muscle involvement, Raynaud's phenomenon, and impairment of forced vital capacity. Concerning SSc, the most common subtype was the diffuse form. Cardiovascular and pulmonary complications are an important cause of death. Anti-centromere, anti-PM/Scl, anti-Scl70, anti-RNA polymerase III, anti-Ku, and anti-RNP were more correlated with this entity, and muscle biopsies may present a more aggressive pattern. Electroneuromyography patterns are quite similar to those found in inflammatory myopathies. The absence of studies with robust methodologies and the large number of case reports and series make more robust statistical analyses such as meta-analyses unfeasible. The characterization of MyoSScOS is important for the formulation of therapeutic measures and specific treatments aiming at better quality of life and prognosis. Greater and better theoretical contributions are necessary to better characterize it.

Effects of long-term treatment with dietary theobromine on rat skeletal muscles.

BACKGROUND: Plastic changes of skeletal muscles, such as hypertrophy and atrophy, are dependent on physiological activities and regulated by a variety of signaling pathways, including cyclic adenosine monophosphate (cAMP) pathway. The cAMP inducing agents, such as the ß2-adrenergic agonist clenbuterol, are known to induce muscle hypertrophy, and has been reported to induce slow-to-fast transitions in rat soleus muscle. Theobromine, one of the active components of cacao, functions as an inhibitor of phosphodiesterase and increases cAMP. This study hypothesized that theobromine, like clenbuterol, can induce muscle hypertrophy and influence contractile properties. METHODS AND RESULTS: Male Wistar rats were fed a normal diet or a diet containing 0.05% theobromine for 20 weeks. Using biochemical, anatomical, and physiological techniques, effects of dietary theobromine on skeletal muscles (soleus, extensor digitorum longus, plantaris, and gastrocnemius) were examined. There were no significant differences in body weight, serum levels of proteins and lipids, muscle weights, dry/wet ratio of muscle weights, mitochondrial oxidation enzyme activity of muscles, isometric contractile properties of muscles, and muscle fatigue between control and theobromine-fed rats. Quantitative analysis of mRNA, however, revealed upregulation of myosin heavy chain 2x and myogenic differentiation 1, as previously reported in clenbuterol-treated muscles. CONCLUSION: The long-term theobromine (0.05%) diet in rats had no effect in inducing muscle hypertrophy and in changing contractile properties, although it had some similar effects of clenbuterol on muscle gene expression.

Blood lipid profile changes in type 2 diabetic rats after tail suspension and reloading.

PURPOSE: The effects of the tail suspension and reloading on the protein and lipid metabolism in muscle and blood in type 2 diabetes mellitus (T2DM) are unclear. This study evaluated the hypothesis that skeletal muscle catabolism is greater in T2DM than in non-diabetes mellitus (non-DM) rats and that the activity-dependent changes in the intramuscular lipid accumulation and blood lipid profile are poorer in T2DM than in non-DM rats. METHODS: T2DM and non-DM rats were suspended for two weeks followed by reloading for two weeks. The muscle and blood were then examined. RESULTS: In contrast to our hypothesis, there was no marked difference between the T2DM and non-DM groups in terms of the skeletal muscle catabolism and activity-dependent changes in intramuscular lipid accumulation. However, the blood lipid profile increased in the T2DM group compared to the non-DM group. One interesting finding in this study was the decrease in non-high-density lipoprotein (non-HDL) cholesterol levels after one week of reloading followed by a significant increase in the non-HDL cholesterol levels after two weeks of reloading in the T2DM group. CONCLUSION: These results suggest that a dramatic increase in activity after a period of inactivity may rapidly improve the blood lipid profile in T2DM rats.

Effect of performing daily activities while standing on the quantity and quality of the thigh muscles in adults with severe cerebral palsy: a cross-sectional study.

[Purpose] To observe the effect of daily standing, as indicated by gross motor function, on the quantity and quality of the thigh muscles in adults with severe cerebral palsy and to obtain data to determine an appropriate intervention that will improve their quality of life. [Participants and Methods] Thirty-three adults with severe cerebral palsy participated in the study. We assessed the gross motor function using the GMFM-66-IS. We then evaluated the quadriceps muscle thickness and the rectus femoris muscle echo intensity using ultrasonography. We divided the participants into the standing and non-standing groups and then examined the correlations of the GMFM-66-IS score to muscle thickness and echo intensity. We calculated the difference in mean muscle thickness and echo intensity between the two groups using an independent t-test. [Results] Significant positive correlations were found between the GMFM-66-IS score and muscle thickness and echo intensity. In the group-specific analysis, no significant correlation was found between echo intensity and the GMFM-66-IS score in either group. Muscle thickness and echo intensity were greater in the participants of the standing group. [Conclusion] Daily standing, as indicated by gross motor function, affected muscle thickness and echo intensity. Quantitative and qualitative data might need to be evaluated when assessing the muscles of adults with severe cerebral palsy using ultrasonography.

Fast repetitive stretch suppresses denervation-induced muscle fibrosis.

BACKGROUND: We aimed to examine the influence of different speeds of stretching on denervation-induced skeletal muscle fibrosis. METHODS: Stretching was passively applied to rat plantaris muscle denervated by sciatic nerve excision in three different cycles of 0.5, 3, or 12 cycles/min, for 20 min/d for 2 weeks. RESULTS: Gene analysis results showed greater expression of fibrosis-related factors with fast stretching compared with non-stretched muscle. Laser Doppler blood flow analysis indicated reduced intramuscular blood flow during stretching. Histological analysis demonstrated fibrotic area decreases in 12 cycles/min stretched muscle compared with non-stretched muscle. CONCLUSIONS: Slower stretching induced greater mRNA expression of collagen and fibroblasts and greater decrement of blood flow. Histologically, faster stretching suppressed fibrosis. These results suggest that fast repetitive stretching of denervated muscle might suppress processes of muscle fibrosis.

Measurement of the cross-sectional area of the hamstring muscles during initial and stretch positions with gravity magnetic resonance imaging.

[Purpose] We aimed to investigate the change rate in the cross-sectional area of each hamstring component to evaluate muscle extensibility and to contribute to the studies on hamstring strain prevention. [Participants and Methods] Fifteen healthy young males volunteered to participate in this study. They performed a knee extension test. For the measurements, we used multi-posture magnetic resonance imaging (gravity magnetic resonance imaging), the open shape of which allows performing body scanning in various positions. We measured the maximum cross-sectional area of the hamstring during the initial and stretch positions from the obtained images. Then, for each muscle, we calculated the maximum cross-sectional area change rate relative to the initial position. [Results] For all hamstring muscles, the maximum cross-sectional area during stretching was significantly smaller than that in the initial position. The maximum cross-sectional area change rate of the semimembranosus was significantly smaller than that of the other 3 muscles (there were no significant differences among these 3 muscles). [Conclusion] The results suggest that the semimembranosus has higher resistance to morphological change than the other muscles, which could be an important limiting factor for the extensibility of the hamstring muscle group.

Perception of trunk inclination during sitting with feet in contact with the floor.

[Purpose] To clarify the sitting postural control, the influences of several reference sitting positions on the perception of the trunk position while sitting with the feet in contact with the floor and keeping the eyes closed were investigated. [Participants and Methods] Fifteen young healthy volunteers participated in the present study. The perception of the trunk position was evaluated by calculating the absolute error (error magnitude) and constant error (error direction) between the reference trunk position (which the subjects memorized; the reference position) and the position that they adopted when reproducing the reference position (the reproduced position). Eight reference positions were set at 5° increments (from 15° backward inclination [-] to 20° forward inclination [+]). [Results] The reference positions had a significant effect on the absolute error, and the absolute error values at -15° and -10° were significantly smaller than at 20°. However, the reference positions had no effect on the constant error. [Conclusion] The present study revealed that the perception of the trunk position while sitting with the feet in contact with the floor is better when inclining backward than when inclining forward. The perception of the trunk position may be higher in a low-stability position and lower in a high-stability position.

Effect of hindlimb unloading and reloading on the soleus and plantaris muscles in diabetic rats.

[Purpose] This study aimed to induce disuse muscle atrophy in Goto-Kakizaki rats, a type 2 diabetes model, to investigate the effects of reloading on the soleus and plantaris muscles. [Materials and Methods] Wistar and Goto-Kakizaki (GK) rats were divided into 6 groups: Wistar Control (WC), GK Control (GC), Wistar Tail suspension (WS), GK Tail suspension (GS), and Wistar Reload (WR), GK Reload (GR). [Results] Investigation of myofiber cross-sectional area in Goto-Kakizaki rat soleus muscles indicated that the GS group showed significantly lower values than the GC and GR groups. No significant differences were observed between the GC and GR groups. However, investigation of plantaris muscles in Goto-Kakizaki rats indicated that the GS and GR groups showed a significant decrease compared to the GC group. No significant differences were found between the GS and GR groups. [Conclusion] Investigation of muscle weight/body weight ratios and myofiber cross-sectional area in tail suspension groups confirmed the induction of muscular atrophy. The differences in the degree of atrophy and recovery in terms of myofiber cross-sectional area observed in Goto-Kakizaki rat plantaris muscles may be influenced by the myofiber type and diabetes.

Anteroposterior perception of the trunk position while seated without the feet touching the floor.

[Purpose] The purpose of this study was to investigate the trunk position perception in the anteroposterior direction in young participants sitting without their feet touching the floor to avoid the influence of the hamstrings tension and the feet pressure on the perception. [Subjects and Methods] Fourteen healthy volunteers were seated on a chair fitted with an original manual goniometer. There were 7 reference positions set at 5° increments, from -15° to 15°, and reproductions of each position were conducted 5 times. Trunk position perception was evaluated by the absolute error between the reproduced trunk angle and the reference position angle. [Results] The results revealed a significant effect of reference position on the absolute error. The absolute error at the -5° reference position was significantly larger than at the -15° and 15° positions, and the absolute error at the 0° position was significantly larger than at the -15°, 10°, and 15° positions. [Conclusion] These results suggest that the perception of extreme forward- and backward-leaning trunk positions while sitting without the feet touching the floor would be higher than in a neutral sitting position. The relationship between the stability of the posture and the perception may be involved in the sitting position.

Perception of leaning backward while standing and patellar movement.

[Purpose] The purpose of this study was to investigate the relationship between the patellar movement and the standing backward leaning perceptibility. [Subjects and Methods] Fourteen volunteers who were confirmed presence of upward patellar movement during backward leaning from the quiet standing posture participated in this study. The quiet standing position, the standing backward leaning position at patellar movement onset and standing position perceptibility were measured. The position of the center of pressure in the anteroposterior direction in standing is represented as the percentage distance from the hindmost point of the heel in relation to the foot length (%FL). [Results] The mean value of the center of pressure on anteroposterior direction positions in quiet standing was 43.2%FL. The patellar movement onset position was 35.1%FL. The individual mean value of standard deviations for the onset position was 2.5%FL. The absolute error at the onset position is specifically and significantly small. [Conclusion] For the subjects whose patellas move during backward leaning in this study, the standing position near the onset position was perceived accurately, probably by the substantial change in sensory information associated with the onset of patellar movement while backward leaning.

Patellar movement perception related to a backward-leaning standing position.

[Purpose] To investigate the patellar movement perception related to backward-leaning standing. [Subjects and Methods] Both the patellar range of motion during backward-leaning standing and perception related to patellar movement were analyzed using television-x irradiation images in 12 randomly selected healthy young individuals. [Results] Starting in a relaxed condition, two types of patellar movements were confirmed: those where the patella moves (patellar movement trials) and those where the patella does not move (patellar non-movement trials) during backward-leaning standing. The rate of the perceived patellar motion in the patellar movement trials was significantly higher (90.9%) than that in the patellar non-movement trials (66.7%). When starting in a quadriceps-contracted condition, the rate of perceived trials (77.0%) was significantly lower than that of the trials started in a relaxed condition. [Conclusion] The perception of patellar movement while backward-leaning standing may contribute to the perception of a backward standing position especially when the patella really moves.

Walking gait changes after stepping-in-place training using a foot lifting device in chronic stroke patients.

[Purpose] The goal of this study was to investigate the efficacy of stepping-in-place training using a foot lifting assist device on the walking gait of chronic hemiparetic stroke patients. [Subjects] Seven patients with chronic hemiplegic stroke (age 80.9±4.9 years) who were attending a local adult daycare facility participated in this study. [Methods] The participants had 2 or 16 weeks of intervention after a baseline period of 2 weeks. Evaluations were performed before the baseline period and before and after the intervention period. The evaluation consisted of a two-dimensional motion analysis of walking and stepping-in-place exercises and a clinical evaluation. [Results] Walking speed increased in three participants after 2 or 16 weeks of intervention. The swing phase percentage increased in the paretic gait cycle, and the time from non-paretic heel contact to paretic heel off decreased during stepping-in-place in these participants. [Conclusion] Given that the transition from the support phase support to the swing phase was shortened after the intervention, the stepping-in-place exercise using the device designed for this study may improve the muscle strength of the lower limb and coordination in the pre-swing phase of the paretic limb.

Relationship between the ability to perform the sit-to-stand movement and the maximum pelvic anteversion and retroversion angles in patients with stroke.

[Purpose] The purpose of this study was to investigate the relationship between the ability to perform the sit-to-stand movement and the maximum pelvic anteversion and retroversion angles of patients. [Subjects] Thirty-two stroke patients (66.7±7.6 years) (>3 months post-stroke) who were able to sit unsupported and 50 age-matched healthy subjects participated in this study. The stroke patients were classified into two groups according to the sit-to-stand movement test: the group that was able to stand up (the stand-able group) (18 persons) and the group that was unable to stand up (the stand-unable group) (14 persons). [Methods] Pelvic anteversion and retroversion maximum angles were measured by a manual goniometer attached to an inclinometer. [Results] The maximum pelvic anteversion angles were -1.6 ± 5.0°, 1.2 ± 2.8°, and -12.4 ± 6.1° in the control group, the stand-able stroke group, and the stand-unable stroke group, respectively. A significant main effect of group was found. An angle discriminating between the two stroke groups was found: the maximum anteversion angles in the stand-able group were distributed above -5°. [Conclusion] The maximum pelvic anteversion angle was significantly smaller in the stand-unable group than in the stand-able and control groups.

Age-related Changes in Maximum Pelvic Anteversion and Retroversion Angles Measured in the Sitting Position.

[Purpose] The purpose of this study was to investigate the relationship between age and the maximum pelvic anteversion and retroversion angles, as well as the associated pelvic range of motion, measured in a sitting position with free knee movement. [Subjects] A total of 132 healthy volunteers (74 women, 58 men; age range, 20-79 years) were divided into six groups based on age (20-29, 30-39, 40-49, 50-59, 60-69, and 70-79 years). [Methods] The maximum pelvic anteversion and retroversion angles were measured manually five times by a goniometer in a sitting position that allowed free movement of the knee joints. [Results] There was a significant effect of age group on the maximum pelvic anteversion and retroversion angles and pelvic range of motion (the difference between these angles). There was a significant correlation between age and the maximum pelvic anteversion angle, maximum pelvic retroversion angle, and pelvic range of motion. [Conclusion] The maximum pelvic anteversion and retroversion angles and pelvic range of motion were significantly correlated with age. The maximum pelvic anteversion angle and pelvic range of motion were most affected by age.

Influence of passive stretching on inhibition of disuse atrophy and hemodynamics of rat soleus muscle.

The purpose of this study was to determine the influence of passive stretching on inhibition of disuse atrophy and hemodynamics among longitudinal regions of the rat soleus muscle. Disuse muscle atrophy was induced by hindlimb suspension for two weeks. Muscle blood flow was evaluated using thallium-201 ((201)Tl) which is a radiotracer that has been reported to be useful to assess blood perfusion in skeletal muscle. Thirty-nine male Wistar rats were divided randomly into 5 groups: control (C: n = 10), a group with hindlimb suspension (HS: n = 7), a group with hindlimb suspension and stretching (ST: n = 7), a group receiving only a single session of stretching after the hindlimb suspension period that was killed just after stretching (HSB: n = 7), and a group receiving only a single session of stretching hindlimb suspension and stretching period that was killed just after stretching (STB: n = 8). From the results of the cross-sectional area (CSA) and the capillary-to-fiber ratio (C/F), muscle atrophy and inhibition of atrophy were shown more in proximal than in distal regions of experimental groups. These results suggest that the alterations of the C/F and CSA were different among muscle regions in experimental groups. These differences may depend on the level of stretching. Moreover, alteration of blood flow resulting from alteration of the mechanical environment had little influence on muscle atrophy or inhibition of atrophy.