Characteristics of muscle fiber type are predictive of skeletal muscle mass and strength in elderly men

OBJECTIVES: To investigate the relationship between skeletal muscle fiber type‐specific characteristics, circulating hormone concentrations, and skeletal muscle mass and strength in older men. DESIGN: Cross‐sectional analyses. SETTING: University research center. PARTICIPANTS: Forty‐one community dwelling elderly men (≥65). MEASUREMENTS: Leg strength (1‐repetition maximum, 1RM) and whole‐body and limb muscle mass were determined, and muscle fiber type composition, cross‐sectional area (CSA), myonuclear content, and satellite cell (SC) content were assessed in skeletal muscle biopsy samples. In addition, blood samples were collected to determine serum testosterone, sex hormone–binding globulin, insulinlike growth factor (IGF)‐1, and IGF binding protein‐3 concentrations. RESULTS: Muscle mass correlated with muscle strength (0.41 ≤ correlation coefficient (r)≤0.72; P<.01). Muscle fiber CSA, myonuclear content, and SC content were significantly lower in type II than in type I muscle fibers. Myonuclear and SC content were positively correlated with muscle fiber CSA. Furthermore, greater muscle fiber CSA (type I and II) was associated with greater thigh muscle area and muscle strength (0.30 ≤ r ≤ 0.45; P<.05). Testosterone concentration was positively correlated with muscle mass and muscle fiber CSA. Regression analysis showed that SC content, myonuclear content, and testosterone concentration are predictive of muscle fiber CSA. Furthermore, muscle mass and type II muscle fiber CSA are predictive of muscle strength. CONCLUSION: Skeletal muscle mass and strength in elderly men are positively correlated with muscle fiber type–specific CSA, myonuclear content, and SC content. These findings support the assumption that a decline in SC content plays an important role in age‐related decline in muscle mass and strength.     

Knee extensor and knee flexor strength: cross-sectional area ratios in young and elderly men.

The relationships between isometric and isokinetic-concentric knee extensor and knee flexor strength, and quadriceps and hamstring cross-sectional area (CSA) were determined in young (n = 13, M = 24.5y) and elderly (n = 12, M = 70.7y) men. Quadriceps and hamstring CSA was determined by computed tomography. Knee extensor and flexor strength at 0 degree/s and 120 degree/s was determined on a Kin-Com isokinetic dynamometer. Compared to the young men, elderly men had significantly smaller quadriceps muscles and were weaker (22-32%) in knee flexion and knee extension at both angular velocities. Strength:CSA ratios were similar at 0 degree/s, but elderly men had decreased ratios for both extensors and flexors at 120 degree/s. Correlations of knee extensor and flexor strength with muscle CSA were significant at both velocities in elderly men, but not at either velocity for the knee flexors in young men. The decrease in isometric strength in elderly men can be accounted for by their decrease in muscle CSA, but their decrease in isokinetic-concentric strength was greater than their loss of CSA. Further study is required to determine the reason for this nonproportional loss of isokinetic-concentric strength.     

Intravoxel incoherent motion diffusion-weighted imaging for monitoring chemotherapeutic efficacy in gastric cancer

AIM: To assess intravoxel incoherent motion diffusionweighted imaging(IVIM-DWI) for monitoring early efficacy of chemotherapy in a human gastric cancer mouse model.METHODS: IVIM-DWI was performed with 12 b-values(0-800 s/mm2) in 25 human gastric cancer-bearing nude mice at baseline(day 0), and then they were randomly divided into control and 1-, 3-, 5- and 7-d treatment groups(n = 5 per group). The control group underwent longitudinal MRI scans at days 1, 3, 5 and 7, and the treatment groups underwent subsequent MRI scans after a specified 5-fluorouracil/calciumfolinate treatment. Together with tumor volumes(TV), the apparent diffusion coefficient(ADC) and IVIM parameters [true water molecular diffusion coefficient(D), perfusion fraction(f) and pseudo-related diffusion coefficient(D*)] were measured. The differences in those parameters from baseline to each measurement(ΔTV%, ΔADC%, ΔD%, Δf% and ΔD*%) were calculated. After image acquisition, tumor necrosis, microvessel density(MVD) and cellular apoptosis were evaluated by hematoxylin-eosin(HE), CD31 and terminal-deoxynucleotidyl transferase mediated nick end labeling(TUNEL) staining respectively, to confirm the imaging findings. Mann-Whitney test and Spearman's correlation coefficient analysis were performed.RESULTS: The observed relative volume increase(ΔTV%) in the treatment group were significantly smaller than those in the control group at day 5(ΔTV_(treatment)% = 19.63% ± 3.01% and ΔTVcontrol% = 83.60% ± 14.87%, P = 0.008) and day 7(ΔTV_(treatment)% = 29.07% ± 10.01% and ΔTV_(control)% = 177.06% ± 63.00%, P = 0.008). The difference in ΔTV% between the treatment and the control groups was not significant at days 1 and 3 after a short duration of treatment. Increases in ADC in the treatment group(ΔADC%_(treatment), median, 30.10% ± 18.32%, 36.11% ± 21.82%, 45.22% ± 24.36%) were significantly higher compared with the control group(ΔADC%_(control), median, 4.98% ± 3.39%, 6.26% ± 3.08%, 9.24% ± 6.33%) at days 3, 5 and 7(P = 0.008, P = 0.016, P = 0.008, respectively). Increases in D in the treatment group(ΔD%_(treatment), median 17.12% ± 8.20%, 24.16% ± 16.87%, 38.54% ± 19.36%) were higher than those in the control group(ΔD%_(control), median-0.13% ± 4.23%, 5.89% ± 4.56%, 5.54% ± 4.44%) at days 1, 3, and 5(P = 0.032, P = 0.008, P = 0.016, respectively). Relative changes in f were significantly lower in the treatment group compared with the control group at days 1, 3, 5 and 7 follow-up(median,-34.13% ± 16.61% vs 1.68% ± 3.40%, P = 0.016;-50.64% ± 6.82% vs 3.01% ± 6.50%, P = 0.008;-49.93% ± 6.05% vs 0.97% ± 4.38%, P = 0.008, and-46.22% ± 7.75% vs 8.14% ± 6.75%, P = 0.008, respectively). D* in the treatment group decreased significantly compared to those in the control group at all time points(median,-32.10% ± 12.22% vs 1.85% ± 5.54%, P = 0.008;-44.14% ± 14.83% vs 2.29% ± 10.38%, P = 0.008;-59.06% ± 19.10% vs 3.86% ± 5.10%, P = 0.008 and-47.20% ± 20.48% vs 7.13% ± 9.88%, P = 0.016, respectively). Furthermore, histopathologic findings showed positive correlations with ADC and D and tumor necrosis(r_s = 0.720, P 0.001; r_s = 0.522, P = 0.007, respectively). The cellular apoptosis of the tumor also showed positive correlations with ADC and D(r_s = 0.626, P = 0.001; r_s = 0.542, P = 0.005, respectively). Perfusionrelated parameters(f and D*) were positively correlated to MVD(r_s = 0.618, P = 0.001; r_s = 0.538, P = 0.006, respectively), and negatively correlated to cellular apoptosis of the tumor(r_s =-0.550, P = 0.004; r_s =-0.692, P 0.001, respectively).CONCLUSION: IVIM-DWI is potentially useful for predicting the early efficacy of chemotherapy in a human gastric cancer mouse model.     

Echo intensity is negatively associated with functional capacity in older women

Muscle quality is an important component of the functional profile of the elderly, and previous studies have shown that both muscle quantity and quality independently contribute to muscle strength of the elderly. This study aimed to verify the association between quadriceps femoris muscle quality, analyzed by specific tension and echo intensity (EI), and rate of torque development (RTD) of the knee extensor muscles with the functional performance in elderly active women. Forty-five healthy, active elderly women (70.28 ± 6.2) volunteered to participate in this study. Quadriceps femoris muscle thickness and EI were determined by ultrasonography. Knee extension isometric peak torque and RTD were obtained from maximal isometric voluntary contraction curves. The 30-s sit-to-stand-up (30SS) test and usual gait speed (UGS) test were applied to evaluate functional performance. Rectus femoris EI presented a significant negative correlation with 30SS (r = −0.505, P < 0.01), UGS (r_s = −0.347, P < 0.05), and isometric peak torque (r = −0.314, P < 0.05). The quadriceps femoris EI correlated negatively with 30SS (r = −0.493, P < 0.01) and isometric peak torque (r = −0.409, P < 0.01). The EI of the quadriceps femoris and all quadriceps muscle portions significantly correlated with RTD. RTD significantly correlated with physical performance in both functional tests (30SS = r = 0.340, P < 0.05; UGS = r_s = 0.371, P < 0.05). We concluded that muscle EI may be an important predictor of functional performance and knee extensor power capacity in elderly, active women.     

Neuromuscular adaptations to water-based concurrent training in postmenopausal women: effects of intrasession exercise sequence

This study investigated the effects of different exercise sequences on the neuromuscular adaptations induced by water-based concurrent training in postmenopausal women. Twenty-one healthy postmenopausal women (57.14 ± 2.43 years) were randomly placed into two water-based concurrent training groups: resistance training prior to (RA, n = 10) or after (AR, n = 11) aerobic training. Subjects performed resistance and aerobic training twice a week over 12 weeks, performing both exercise types in the same training session. Upper (elbow flexors) and lower-body (knee extensors) one-repetition maximal test (1RM) and peak torque (PT) (knee extensors) were evaluated. The muscle thickness (MT) of upper (biceps brachii) and lower-body (vastus lateralis) was determined by ultrasonography. Moreover, the maximal and submaximal (neuromuscular economy) electromyographic activity (EMG) of lower-body (vastus lateralis and rectus femoris) was measured. Both RA and AR groups increased the upper- and lower-body 1RM and PT, while the lower-body 1RM increases observed in the RA was greater than AR (34.62 ± 13.51 vs. 14.16 ± 13.68 %). RA and AR showed similar MT increases in upper- and lower-body muscles evaluated. In addition, significant improvements in the maximal and submaximal EMG of lower-body muscles in both RA and AR were found, with no differences between groups. Both exercise sequences in water-based concurrent training presented relevant improvements to promote health and physical fitness in postmenopausal women. However, the exercise sequence resistance–aerobic optimizes the strength gains in lower limbs.     

Activity-induced pain in rheumatoid arthritis functional class II and its relations with demographic,medical, functional,psychosocial, and work variables. Result of a survey in bollnäs medical district,Sweden, II

One aim of this study was to describe inflammatory activity, joint destruction, work status, and demographic factors in a group of 69 American Rheumatism Association functional class-II rheumatoid arthritis patients: 56 women and 13 men, mean age 54 years (SD 11), mean symptom duration 14 years (SD 11). Another aim was to determine correlations between activity-induced pain and other variables. Patients were assessed with Ritchie's articular index, Larsen's radiologic index, and laboratory tests. Deformity in hands and knee joints, and grip strength, were determined. Results from earlier investigations of functional impairment and psychosocial capacity were also used. Of the patients, 4% had high inflammatory activity. Joint erosions were found in between 4% (knee joints) and 55% (wrists) of the joints examined. Of the patients aged <65, 43% were working. Activity-induced pain was related with work status (p = 0.0002). It also correlated significantly (p ⩽ 0.01) with inflammatory activity (r_s = 0.34), but not with joint destruction (r_s = 0.21).     

Differences in the neuromuscular capacity and lean muscle tissue in old and older community-dwelling adults

BACKGROUND: This study investigated whether there was a worsening of the neuromuscular capacity of older adults after the seventh decade of life. METHODS: Fifteen healthy community-dwelling old (< 70 years of age) and 15 older adults (> or = 70 years of age) were assessed for maximal isometric strength (MVC) and force production characteristics, a one-repetition maximum (1-RM) performance, electromyographic (EMG) activity, and bone-free lean tissue (BFLT) mass of the lower extremity. RESULTS: The isometric MVC, 1-RM, and BFLT mass values in the old group were significantly greater than in the older group. In addition, the individual BFLT mass values correlated significantly with the isometric MVC values (r = .85) and the 1-RM scores of the thigh muscle groups (r = .54-.80). The old group generated significantly greater isometric maximal rate of torque development than the older group and performed significantly better at all intervals of the absolute and relative force-time curves. The voluntary muscle activation of the knee extensors of the old group produced significantly higher integrated EMG (iEMG) activity at each epoch in the early iEMG-time curve compared with the old group. CONCLUSIONS: The results suggest that the age-related deterioration in maximal strength measures and rapid force production characteristics in older adults could be related to a reduction in the mass and neural activation of the thigh muscles. The deterioration of the neuromuscular system of community-dwelling older adults may contribute to an increased difficulty in performing daily activities and may increase their risks of tripping and falling.     

Nutritional status is associated with physical function and disability in older adults with chronic heart failure

BackgroundThe association between nutritional status (NS) and physical performance and disability in older adults with chronic heart failure (CHF) is not well established. We aimed at evaluating whether NS, estimated using the Mini Nutritional Assessment (MNA), is associated with gait speed (GS) and disability (ADL/IADL impairment) in this population and to assess whether energy intake (EI) and appendicular skeletal muscle mass index (ASMMI) influence this relationship.MethodsIn this cross-sectional study we enrolled 88 older adults admitted to a cardiology outpatient clinic for CHF. MNA was analyzed both as continuous and categorical variable (risk of malnutrition [RM]/well-nourished [WN]). The association between NS and GS and disability was assessed using linear and logistic regression models, respectively, crude, adjusted firstly for age, sex, ejection fraction, and mood status, and then for EI and ASMMI.ResultsMean age was 77.8 years, 73% were men. MNA score was positively associated with GS: β adjusted = 0.022, P = 0.035; the coefficient was unaffected by adjustment for EI and ASMMI (β = 0.022, P = 0.052). Compared to WN, RM participants had a lower gait speed (0.82 vs 0.99 m/s, P = 0.006); the difference was attenuated after adjustment for potential confounders (β − = 0.138, P = 0.055). MNA score was inversely associated with ADL impairment (Adjusted OR: 0.80, 95%CI 0.64–0.98), but not with IADL impairment (Adjusted OR: 0.94, 95%CI 0.78–1.13).ConclusionReduced MNA score is associated with poorer physical function and ADL impairment in older adults affected by CHF, independently of EI and ASMMI. Routinely evaluation of NS should be performed in this population.     

Relationships among age-associated strength changes and physical activity level, limb dominance, and muscle group in women

This study investigated the magnitude and rate of age-associated strength reductions in Australian independent urban-dwelling women and the relationship to muscle groups, limb dominance, and physical activity level. Independent urban-dwelling women aged 20 to 89 years (N = 217) performed maximal voluntary contractions with the dominant and nondominant knee extensors, plantar flexors, and handgrip. Anthropometric measurements were made and questionnaire responses used to obtain current physical activity levels. Trend analysis within analysis of variance and regression analysis on strength was performed. Limb muscle strength was found to be associated with increased age, muscle group, limb dominance, and activity. Self-reported physical activity levels declined with age but women who were more physically active for their age group were stronger in all muscle groups and had more lean body mass and lean thigh and leg cross-sectional area than relatively inactive women. Slopes of the linear reductions of maximal voluntary strength of the knee extensors, plantar flexors, and handgrip with age were significantly different (p < .05) at 9.3%, 7.4%, and 6.2% per decade, respectively. The limb muscle strength of healthy Australian independent and urban-dwelling women aged 20 to 89 years was found to be associated with age and three aspects of disuse: muscle group, relative levels of physical activity, and limb dominance.     

MUSCLE STRENGTH IN HEALTHY PEOPLE AND IN PATIENTS SUFFRING FROM RECENT-ONSET INFLAMMATORY ARTHRIRIS

Neuromuscular function was compared among 20 patients with relativelyrecent onset (symptomatic period 17 ± 24 months) rheumatoidarthritis (RA) (experimental group; EG), and 20 age- and sex-matchedhealthy people (control group; CG).The comparison was repeatedafter a period of 6 months, when 16 patients had carried outprogressive strength training. At baseline maximal grip strengthand maximal dynamic unilateral strength of the knee extensorsin the EG were significantly (P < 0.05) lower in comparisonto the CG. The groups did not differ from each other in maximalisometric strength of the trunk flexors and extensors or theknee extensors. The 6-month dynamic strength training in theEG resulted in significant increases in maximal dynamic strengthof the knee extensors (P < 0.001), in isometric grip strength(P < 0.001) and in isometric strength of the trunk flexors(P < 0.05) and extensors (P < 0.05) to the level of thehealthy controls. Only minor changes took place in explosivestrength and maximal isometric strength of the knee extensors.Erythrocyte sedimentation rate (P < 0.001), Ritchie's articularindex (P < 0.01) and modified health assessment questionnaire(P < 0.01) improved significantly during the training period.The results suggest that inflammatory arthritis decreases dynamicand/or isometric muscle strength in selected muscle groups ofthe body already in the early stages of disease. However, progressivedynamic strength training rapidly increases the neuromuscularperformance capacity of the patients even to the level of healthypeople without detrimental effects on disease activity. KEY WORDS: Recent-onset inflammatory arthritis, Muscle strength, Neuromuscular function, Strength training, Disease activity, Healthy people     

Muscle size,strength, and bone geometry in the upper limbs of young and old men

BACKGROUND: Bone loss in old men is associated with a decrease in muscle mass and strength. However, the influence of muscle size and strength on age-related changes in bone geometry has not been comprehensively described. Methods. Men in their third (group I, 23 +/- 3 y, n = 20), eighth (group II, 77 +/- 1 y, n = 10), and ninth (group III, 86 +/- 4 y, n = 13) decades of age were studied. The cross-sectional area (CSA) of the elbow flexors, elbow extensors, and forearm muscles, the total area (TA), cortical area (CA), and medullary area (MA) of the midhumerus, and distal third of the radius and ulna (n = 7 group II; n = 6 group III) were measured with magnetic resonance imaging. The maximal isometric strength (MVC) of the elbow flexors and elbow extensors was also determined. RESULTS: The CSA and MVC of the arm muscles (elbow flexors plus elbow extensors) were less in group II (-17% and -22%) and III (-32% and -39%), respectively, compared to group I. However, forearm CSA was less (-21%) in group III only. The TA and MA of all bones were greater in the older groups. The CA of the humerus (-14%) and ulna (-10%), but not the radius, was less in group III compared to group I, whereas CA was unchanged in group II. Stepwise multiple linear regression determined that arm muscle CSA (r = 0.52, p <.01) and forearm muscle CSA (r = 0.41, p <.05) provided the best prediction of CA in the humerus and forearm, respectively. CONCLUSIONS: Muscle size and strength are important determinants of CA in the humerus and forearm. The lower CA in the ninth decade may be explained, in part, by reduced bone strains due to a smaller muscle mass.     

Subordinate quadratic forms and their complementary forms

Theorem 1. For α, β on the range 1,..., μ, let Q(z) = ^*aαβzαzβ be a real valued, nonsingular, symmetric quadratic form. For positive integers r and s such that μ = r + s set (z₁,..., z_μ) = (u₁,..., u_r:S₁,..., S_n), Q(z) = P(u, s) and [Formula: see text] Let B = (z⁽¹⁾,..., z^(r)) be a base “over R” for points z ε π_r. For an arbitrary r-tuple ω₁,..., ω_r set [Formula: see text] index H_B(ω) = κ and nullity H_B(ω) = ν. Then [Formula: see text]     

Strength training at high versus low external resistance in older adults: Effects on muscle volume,muscle strength,and force–velocity characteristics

Muscle adaptations can be induced by high-resistance exercise. Despite being potentially more suitable for older adults, low-resistance exercise protocols have been less investigated. We compared the effects of high- and low-resistance training on muscle volume, muscle strength, and force–velocity characteristics. Fifty-six older adults were randomly assigned to 12 weeks of leg press and leg extension training at either HIGH (2 × 10–15 repetitions at 80% of one repetition maximum (1RM)), LOW (1 × 80–100 repetitions at 20% of 1RM), or LOW + (1 × 60 repetitions at 20% of 1RM, followed by 1 × 10–20 repetitions at 40% of 1RM). All protocols ended with muscle failure. Leg press and leg extension of 1RM were measured at baseline and post intervention and before the first training session in weeks 5 and 9. At baseline and post intervention, muscle volume (MV) was measured by CT-scan. A Biodex dynamometer evaluated knee extensor static peak torque in different knee angles (PT_stat90°, PT_stat120°, PT_stat150°), dynamic peak torque at different speeds (PT_dyn60°s^− 1, PT_dyn180°s^− 1, PT_dyn240°s^− 1), and speed of movement at 20% (S₂₀), 40% (S₄₀), and 60% (S₆₀) of PT_stat90°. HIGH and LOW + resulted in greater improvements in 1RM strength than LOW (p < 0.05). These differences were already apparent after week 5. Similar gains were found between groups in MV, PT_stat, PT_dyn60°s^− 1, and PT_dyn180°s^− 1. No changes were reported in speed of movement. HIGH tended to improve PT_dyn240°s^− 1 more than LOW or LOW + (p = 0.064). In conclusion, high- and low-resistance exercises ending with muscle failure may be similarly effective for hypertrophy. High-resistance training led to a higher increase in 1RM strength than low-resistance training (20% of 1RM), but this difference disappeared when using a mixed low-resistance protocol in which the resistance was intensified within a single exercise set (40% of 1RM). Our findings support the need for more research on low-resistance programs in older age, in particular long-term training studies and studies focusing on residual effects after training cessation.     

Proprioception,dynamic balance and maximal quadriceps strength in females with knee osteoarthritis and normal control subjects

Background: Osteoarthritis (OA) is one of the most common musculoskeletal complaints worldwide. The knee is the most frequently involved joint of the lower limb in OA. Knee joint proprioception, dynamic balance and maximal quadriceps strength may be impaired in patients with knee OA. Objective: To investigate whether females with knee OA have reduced knee joint proprioception, balance responses and quadriceps strength compared with normal controls. Methods: We undertook a cross‐sectional study of 30 females with knee OA and 30 controls. Knee joint proprioception was measured using electrogoniometer. Dynamic balance response was determined using a step test. Quadriceps strength was measured isometrically using a modified Tornvall chair. Results: Subjects with OA had greater mean error, poorer dynamic balance and less quadriceps strength than non‐symptomatic ones (P < 0.001). Increasing age was associated with a decline in proprioceptive acuity for both controls and patients (r = 0.40, P < 0.001). In subjects with knee OA, decreased dynamic balance was associated with increasing weight (r = 0.30, P < 0.001) and reduced quadriceps strength (r = –0.37, P = 0.002). Conclusion: Compared with age and sex‐matched controls, females with symptomatic knee OA have reduced knee proprioception, balance responses and quadriceps strength.     

Inter-muscular adipose tissue is associated with adipose tissue inflammation and poorer functional performance in central adiposity

BackgroundThe presence of concomitant sarcopenia and obesity in sarcopenic obesity (SO) confers worse functional, morbidity and mortality outcomes compared to either alone. Excess adiposity and central redistribution of fats are associated with systemic inflammation and ectopic tissue fat infiltration in forms of Intermuscular adipose tissue (IMAT). Our study examines the profile of IMAT across a spectrum of body compositions and associations with physical performance and inflammatory biomarkers including Monocyte Chemoattractant Protein-1 (MCP-1), a novel biomarker of adipose tissue inflammation.Methods187 community dwelling elderly participants were recruited and classified into 4 subgroups: normal, obese, sarcopenia and SO, using validated criteria for sarcopenia and waist circumference to define central obesity. We performed magnetic resonance imaging of mid-thigh sections to segment IMAT and muscle. Participants were assessed for muscle strength, physical performance and blood inflammatory biomarkers of interleukin-6, C-Reactive Protein and MCP-1. We examined correlation of IMAT(ratio) with muscle function measures and blood biomarkers. Multiple regression analyses were used to examine the association of body composition types and IMAT(ratio) with muscle function.ResultsIMAT(ratio) was highest in SO and obese groups. Overall, higher IMAT(ratio) is significantly associated with raised MCP-1, lower gait speed and muscle strength. SO had lowest scores in Short Physical Performance Battery (SPPB), gait speed, hand-grip and knee extension strength. IMAT(ratio) is independently associated with SPPB and handgrip strength, whilst SO is independently associated with muscle strength.ConclusionOur results suggest the possible role of IMAT as a candidate imaging biomarker for adipose tissue inflammation and associated poorer functional outcomes in SO.     

Value of C reactive protein in the assessment of erosive osteoarthritis of the hand

Methods: Ninety eight patients, 67 with EOA and 31 with non-EOA of the hand, were included in the study and analysed for radiographic score (RS), number of erosions, and joint count (JC) at clinical observation and at bone scintigraphy. CRP was assayed in a serum sample by a highly sensitive immunonephelometric method.

Results: The median (interquartile range) CRP level was 4.7 (2.4–6.9) mg/l in the EOA and 2.1 (0.5–4.9) mg/l in the non-EOA group (p = 0.001). In all patients, CRP correlated with RS (r_s = 0.43, p<0.001), and mainly with JC at clinical observation (r_s = 0.72, p<0.001) and at bone scintigraphy (r_s = 0.47, p<0.001). The correlation of CRP with RS and JC was confirmed at clinical observation and at bone scintigraphy in the EOA subgroup, but only with JC at clinical observation in the non-EOA subgroup.

Conclusions: CRP levels are higher in EOA than in non-EOA patients. These levels probably reflect the disease activity of EOA, as suggested by correlations between CRP and JC at clinical observation and at bone scintigraphy.

     

Deficits in Lower Limb Muscle Reflex Contraction Latency and Peak Force Are Associated With Impairments in Postural Control and Gross Motor Skills of Children With Developmental Coordination Disorder: A Cross-Sectional Study

This cross-sectional, exploratory study aimed to compare neuromuscular performance, balance and motor skills proficiencies of typically developing children and those with developmental coordination disorder (DCD) and to determine associations of these neuromuscular factors with balance and motor skills performances in children with DCD.One hundred thirty children with DCD and 117 typically developing children participated in the study. Medial hamstring and gastrocnemius muscle activation onset latencies in response to an unexpected posterior-to-anterior trunk perturbation were assessed by electromyography and accelerometer. Hamstring and gastrocnemius muscle peak force and time to peak force were quantified by dynamometer, and balance and motor skills performances were evaluated with the Movement Assessment Battery for Children (MABC).Independent t tests revealed that children with DCD had longer hamstring and gastrocnemius muscle activation onset latencies (P < 0.001) and lower isometric peak forces (P < 0.001), but not times to peak forces (P > 0.025), than the controls. Multiple regression analysis accounting for basic demographics showed that gastrocnemius peak force was independently associated with the MABC balance subscore and ball skills subscore, accounting for 5.7% (P = 0.003) and 8.5% (P = 0.001) of the variance, respectively. Gastrocnemius muscle activation onset latency also explained 11.4% (P < 0.001) of the variance in the MABC ball skills subscore.Children with DCD had delayed leg muscle activation onset times and lower isometric peak forces. Gastrocnemius peak force was associated with balance and ball skills performances, whereas timing of gastrocnemius muscle activation was a determinant of ball skill performance in the DCD population.     

Muscle strength,functional performance,and self‐reported outcomes four years after arthroscopic partial meniscectomy in middle‐aged patients

Objective

To examine thigh muscle strength, functional performance, and self‐reported outcome in patients with nontraumatic meniscus tears 4 years after operation, and to study the impact of a strength deficit on self‐reported outcome and evaluate the feasibility of 3 performance tests in this patient group.

Methods

The study group comprised 45 patients (36% women, mean age 46.7) who had an arthroscopic partial meniscectomy a mean of 4 years (range 1–6 years) previously. Main outcome measures included isokinetic strength of knee extensors and flexors, functional performance (1‐leg hop, 1‐leg rising, and square‐hop tests), and a self‐reported questionnaire (Knee Injury and Osteoarthritis Outcome Score).

Results

We found lower knee extensor strength and worse 1‐leg rising capacity in the operated leg, but no difference between operated and nonoperated leg for knee flexors (P ≤ 0.004 and P > 0.3, respectively). Patients with a stronger quadriceps of the operated leg compared with the nonoperated leg had less pain and better function and quality of life (r = 0.4–0.6, P ≤ 0.010). We found the 1‐leg rising and 1‐leg hop tests to be suitable performance tests in middle‐aged meniscectomy patients.

Conclusion

Quadriceps strength is reduced in the meniscectomized leg compared with the nonoperated leg 4 years after surgery. This relative quadriceps weakness significantly affects objective and self‐reported knee function, pain, and quality of life, indicating the importance of restoring muscle function after meniscectomy in middle‐aged patients.

     

Sternocleidomastoid size and upper trapezius muscle thickness in congenital torticollis patients: A retrospective observational study

The purpose of this study was to investigate the upper trapezius muscle thickness (UTMT) in congenital muscular torticollis (CMT) patients and determine the correlation among sternocleidomastoid muscle thickness (SCMT), accessory nerve (AN) cross-sectional area (CSA), and UTMT in CMT.This retrospective study consisted of 2 participant groups: Group 1 (SCM mass CMT, n = 20) and Group 2 (Postural CMT, n = 22). For both groups, B-mode ultrasound was performed by a physiatrist to measure the SCMT and UTMT and calculate the CSA of the AN. The correlation among SCMT, CSA of the AN, and UTMT in both groups was evaluated.The between-group comparison revealed that Group 1 had significantly greater SCMT, UTMT, and CSA of the AN on the affected side than Group 2 (P < .05). The intragroup comparison between the affected and unaffected sides also revealed that, in Group 1, the SCMT, UTMT, and CSA of the AN were significantly higher on the affected side than on the unaffected side (P < .05), whereas no significant differences were observed in Group 2. In Group 1, a positive correlation (r = 0.55) was observed between the UTMT and CSA of the AN on the affected side, but not observed between the SCMT and CSA of the AN.The findings of the study indicate that sternocleidomastoid muscle size may impact the thickness of the upper trapezius muscle via the accessory nerve in patients with congenital torticollis.     

Central adiposity associations to carbohydrate and lipid metabolism in individuals with complete motor spinal cord injury

Altered body composition has been suggested as a major factor for the high prevalence of impaired glucose tolerance, insulin resistance, and dyslipidemia in individuals with spinal cord injury (SCI). The contributions of visceral adipose tissue (VAT), trunk subcutaneous adipose tissue (SAT), and the VAT/SAT ratio to these metabolic derangements in SCI are poorly defined. Thirteen individuals with traumatic motor complete SCI underwent a metabolic study after overnight fasting to measure plasma glucose, insulin, and lipid concentrations. Fast spin echo magnetic resonance imaging was used to quantify the average cross-sectional area (CSA), volumes, and percentages of VAT and SAT across multiaxial slices. Dual-energy x-ray absorptiometry was performed to measure whole-body fat-free mass and fat mass. Visceral adipose tissue CSA was positively related to fasting plasma glucose (r = 0.77, P = .002) and to the ratio of cholesterol to high-density lipoproteins (HDL-C) (r = 0.71, P = .006). Visceral adipose tissue volume was related to total cholesterol (r = 0.57, P = .043) and to low-density lipoproteins (r = 0.59, P = .032). Trunk %SAT was negatively related to glucose concentration and area under the curve (both, r = −0.61, P = .026). Fasting plasma insulin was negatively related to the VAT CSA and VAT/SAT ratio (both, r = −0.57, P = .043). Partial correlations showed a negative association between trunk %SAT and glucose area under the curve (r = −0.61, P = .02) and a positive association with HDL-C (r = 0.64, P = .033). The findings suggest that an increase in VAT, SAT, and VAT/SAT is associated with the adverse metabolic profile commonly seen in individuals with SCI. Trunk %SAT is associated with a reduced risk of glucose intolerance and an increased HDL-C.