CT-Based Muscle Attenuation May be Able to Account for Age- and Muscle-Specific Differences in Maximum Muscle Stress

Author(s):  
Dennis E. Anderson ◽  
Alexander G. Bruno ◽  
Brett T. Allaire ◽  
Mary L. Bouxsein

In musculoskeletal modeling, isometric muscle strength has been primarily determined based on muscle size. Specifically, the maximum force a muscle can produce may be calculated as: (1)FMAX=MMS×PCSA where FMAX is maximum isometric muscle force, MMS is maximum muscle stress, and PCSA is muscle physiological cross-sectional area. In general, modeling studies have selected a constant value of MMS, and applied it to all muscles in the model. However, the values reported in the literature for MMS vary widely [1, 2], from as little as 23 N/cm2 up to 137 N/cm2. Furthermore, MMS is likely lower in older adults than young adults, as age-related declines in muscle strength are significantly greater than declines in muscle mass [3], and the specific tension of gastrocnemius fascicles is 30% lower in elderly men than young men [4]. In addition, MMS is not constant between muscle groups. For example, the MMS of the elbow flexors is much greater than that of the elbow extensors [1], while the MMS of the ankle dorsiflexors is more than twice that of the ankle plantar flexors [5]. Thus, the use of a single constant for MMS in musculoskeletal models does not account for differences between individuals or muscle groups, and there is a need for a quantitative approach to assign different values of MMS to muscles in musculoskeletal models.

1991 ◽  
Vol 71 (2) ◽  
pp. 644-650 ◽  
Author(s):  
W. R. Frontera ◽  
V. A. Hughes ◽  
K. J. Lutz ◽  
W. J. Evans

The isokinetic strength of the elbow and knee extensors and flexors was measured in 200 healthy 45- to 78-yr-old men and women to examine the relationship between muscle strength, age, and body composition. Peak torque was measured at 60 and 240 degrees/s in the knee and at 60 and 180 degrees/s in the elbow by use of a Cybex II isokinetic dynamometer. Fat-free mass (FFM) was estimated by hydrostatic weighing in all subjects, and muscle mass (MM) was determined in 141 subjects from urinary creatinine excretion. FFM and MM were significantly lower (P less than 0.001) in the oldest group. Strength of all muscle groups at both testing speeds was significantly (P less than 0.006) lower (range 15.5–26.7%) in the 65- to 78- than in the 45- to 54-yr-old men and women. When strength was adjusted for FFM or MM, the age-related differences were not significant in all muscle groups except the knee extensors tested at 240 degrees/s. Absolute strength of the women ranged from 42.2 to 62.8% that of men. When strength was expressed per kilogram of MM, these gender differences were smaller and/or not present. These data suggest that MM is a major determinant of the age- and gender-related differences in skeletal muscle strength. Furthermore, this finding is, to a large extent, independent of muscle location (upper vs. lower extremities) and function (extension vs. flexion).


2000 ◽  
Vol 88 (4) ◽  
pp. 1321-1326 ◽  
Author(s):  
Walter R. Frontera ◽  
Virginia A. Hughes ◽  
Roger A. Fielding ◽  
Maria A. Fiatarone ◽  
William J. Evans ◽  
...  

The present study examines age-related changes in skeletal muscle size and function after 12 yr. Twelve healthy sedentary men were studied in 1985–86 (T1) and nine (initial mean age 65.4 ± 4.2 yr) were reevaluated in 1997–98 (T2). Isokinetic muscle strength of the knee and elbow extensors and flexors showed losses ( P < 0.05) ranging from 20 to 30% at slow and fast angular velocities. Computerized tomography ( n = 7) showed reductions ( P < 0.05) in the cross-sectional area (CSA) of the thigh (12.5%), all thigh muscles (14.7%), quadriceps femoris muscle (16.1%), and flexor muscles (14.9%). Analysis of covariance showed that strength at T1 and changes in CSA were independent predictors of strength at T2. Muscle biopsies taken from vastus lateralis muscles ( n = 6) showed a reduction in percentage of type I fibers (T1 = 60% vs. T2 = 42%) with no change in mean area in either fiber type. The capillary-to-fiber ratio was significantly lower at T2 (1.39 vs. 1.08; P = 0.043). Our observations suggest that a quantitative loss in muscle CSA is a major contributor to the decrease in muscle strength seen with advancing age and, together with muscle strength at T1, accounts for 90% of the variability in strength at T2.


2014 ◽  
Vol 49 (5) ◽  
pp. 647-653 ◽  
Author(s):  
Ann M. Cools ◽  
Tanneke Palmans ◽  
Fredrik R. Johansson

Context Tennis requires repetitive overhead movements that can lead to upper extremity injury. The scapula and the shoulder play a vital role in injury-free playing. Scapular dysfunction and glenohumeral changes in strength and range of motion (ROM) have been associated with shoulder injury in the overhead athlete. Objective To compare scapular position and strength and shoulder ROM and strength between Swedish elite tennis players of 3 age categories (&lt;14, 14–16, and &gt;16 years). Design Cross-sectional study. Setting Tennis training sports facilities. Patients or Other Participants Fifty-nine adolescent Swedish elite tennis players (ages 10–20 years) selected based on their national ranking. Main Outcome Measure(s) We used a clinical screening protocol with a digital inclinometer and a handheld dynamometer to measure scapular upward rotation at several angles of arm elevation, isometric scapular muscle strength, glenohumeral ROM, and isometric rotator cuff strength. Results Players older than 16 years showed less scapular upward rotation on the dominant side at 90° and 180° (P &lt; .05). Although all absolute scapular muscle strength values increased with age, there was no change in the body-weight–normalized strength of the middle (P = .9) and lower (P = .81) trapezius or serratus anterior (P = .17). Glenohumeral internal-rotation ROM and total ROM tended to decrease, but this finding was not statistically significant (P = .052 and P = .06, respectively). Whereas normalized internal-rotator strength increased from 14 to 16 years to older than 16 years (P = .009), normalized external-rotator and supraspinatus strength remained unchanged. Conclusions Age-related changes in shoulder and scapular strength and ROM were apparent in elite adolescent tennis players. Future authors should examine the association of these adaptations with performance data and injury incidence.


2021 ◽  
Vol 12 ◽  
Author(s):  
Britta Hanssen ◽  
Nicky Peeters ◽  
Ines Vandekerckhove ◽  
Nathalie De Beukelaer ◽  
Lynn Bar-On ◽  
...  

Muscle weakness is a common clinical symptom in children with spastic cerebral palsy (SCP). It is caused by impaired neural ability and altered intrinsic capacity of the muscles. To define the contribution of decreased muscle size to muscle weakness, two cohorts were recruited in this cross-sectional investigation: 53 children with SCP [median age, 8.2 (IQR, 4.1) years, 19/34 uni/bilateral] and 31 children with a typical development (TD) [median age, 9.7 (IQR, 2.9) years]. Muscle volume (MV) and muscle belly length for m. rectus femoris, semitendinosus, gastrocnemius medialis, and tibialis anterior were defined from three-dimensional freehand ultrasound acquisitions. A fixed dynamometer was used to assess maximal voluntary isometric contractions for knee extension, knee flexion, plantar flexion, and dorsiflexion from which maximal joint torque (MJT) was calculated. Selective motor control (SMC) was assessed on a 5-point scale for the children with SCP. First, the anthropometrics, strength, and muscle size parameters were compared between the cohorts. Significant differences for all muscle size and strength parameters were found (p ≤ 0.003), except for joint torque per MV for the plantar flexors. Secondly, the associations of anthropometrics, muscle size, gross motor function classification system (GMFCS) level, and SMC with MJT were investigated using univariate and stepwise multiple linear regressions. The associations of MJT with growth-related parameters like age, weight, and height appeared strongest in the TD cohort, whereas for the SCP cohort, these associations were accompanied by associations with SMC and GMFCS. The stepwise regression models resulted in ranges of explained variance in MJT from 29.3 to 66.3% in the TD cohort and from 16.8 to 60.1% in the SCP cohort. Finally, the MJT deficit observed in the SCP cohort was further investigated using the TD regression equations to estimate norm MJT based on height and potential MJT based on MV. From the total MJT deficit, 22.6–57.3% could be explained by deficits in MV. This investigation confirmed the disproportional decrease in muscle size and muscle strength around the knee and ankle joint in children with SCP, but also highlighted the large variability in the contribution of muscle size to muscle weakness.


1988 ◽  
Vol 64 (3) ◽  
pp. 1017-1021 ◽  
Author(s):  
V. A. Convertino ◽  
D. F. Doerr ◽  
J. F. Flores ◽  
G. W. Hoffler ◽  
P. Buchanan

Leg compliance is "causally related with greater susceptibility" to orthostatic stress. Since peak O2 uptake (peak VO2) and muscle strength may be related to leg compliance, we examined the relationships between leg compliance and factors related to muscle size and physical fitness. Ten healthy men, 25-52 yr, underwent tests for determination of vascular compliance of the calf (Whitney mercury strain gauge), peak VO2 (Bruce treadmill), calf muscle strength (Cybex isokinetic dynamometer), body composition (densitometry), and anthropometric measurements of the calf. Cross-sectional areas (CSA) of muscle, fat, and bone in the calf were determined by computed tomography scans. Leg compliance was not significantly correlated with any variables associated with physical fitness per se (peak VO2, calf strength, age, body weight, or composition). Leg compliance correlated with calf CSA (r = -0.72, P less than 0.02) and calculated calf volume (r = -0.67, P less than 0.03). The most dominant contributing factor to the determination of leg compliance was CSA of calf muscle (r = -0.60, P less than 0.06), whereas fat and bone were poor predictors (r = -0.11 and 0.07, respectively). We suggest that leg compliance is less when there is a large muscle mass providing structural support to limit expansion of the veins. This relationship is independent of aerobic and/or strength fitness level of the individual.


2015 ◽  
pp. 1-4
Author(s):  
F. BUCKINX ◽  
J.L. CROISIER ◽  
J.Y. REGINSTER ◽  
J. PETERMANS ◽  
E. GOFFART ◽  
...  

This research aimed to assess the correlation between isometric muscle strength of the lower limb and motor skills. This is a cross sectional study performed among volunteer nursing home residents included in the SENIOR (Sample of Elderly Nursing home Individuals: an Observational Research) cohort. The present analysis focused on isometric muscle strength of 6 lower limb muscle groups (i.e. knee extensors, knee flexors, hip abductors, hip extensors, ankle flexors and ankle extensors), assessed using a validated hand-held dynamometer (i.e. the MicroFET2 device), and motor skills evaluated using the Tinetti test, the Timed Up and Go test, the Short Physical Performance Battery test (SPPB) and the walking speed. The relationship between all these parameters was tested by means of a multiple correlation, adjusted on age, sex and body mass index. 450 nursing home residents (69.8% of women) with a mean age of 83.1±9.4 years were included in this study. Our results showed a significant inverse correlation between lower limb muscle strength and the time required to perform the TUG test or gait speed, except for ankle flexors and ankle extensors. The relationship between the Tinetti test or the SPPB score, and lower limb muscle strength was significant, except for ankle flexors and ankle extensors. In conclusion, a positive association between lower limb muscle strength of the four main muscle groups and motor skills of the elderly nursing residents was found in this research. Therefore, special attention should be given to these muscle groups during rehabilitation programs.


2021 ◽  
pp. 1-9
Author(s):  
Ahalee C. Farrow ◽  
Ty B. Palmer

This study aimed to examine the effects of age on hip flexion maximal and rapid strength and rectus femoris (RF) muscle size and composition in men. Fifteen young (25 [3] y) and 15 older (73 [4] y) men performed isometric hip flexion contractions to examine peak torque and absolute and normalized rate of torque development (RTD) at time intervals of 0 to 100 and 100 to 200 milliseconds. Ultrasonography was used to examine RF muscle cross-sectional area and echo intensity. Peak torque, absolute RTD at 0 to 100 milliseconds, and absolute and normalized RTD at 100 to 200 milliseconds were significantly lower (P = .004–.045) in the old compared with the young men. The older men exhibited lower cross-sectional area (P = .015) and higher echo intensity (P = .007) than the young men. Moreover, there were positive relationships between cross-sectional area and absolute RTD at 0 to 100 milliseconds (r = .400) and absolute RTD at 100 to 200 milliseconds (r = .450) and negative relationships between echo intensity and absolute RTD at 100 to 200 milliseconds (r = −.457) and normalized RTD at 100 to 200 milliseconds (r = −.373). These findings indicate that hip flexion maximal and rapid strength and RF muscle size and composition decrease in old age. The relationships observed between ultrasound-derived RF parameters and measurements of RTD suggest that these age-related declines in muscle size and composition may be relevant to hip flexion rapid torque production.


2022 ◽  
Author(s):  
Yahya Pasdar ◽  
Shima Moradi ◽  
Saman Saedi ◽  
Behrooz Hamzeh ◽  
Farid Najafi

Abstract The Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet aims to reduce dementia and the decline in brain health that often occurs as people get older. Loss of muscle strength (sarcopenia) is a geriatric syndrome that has associated with the loss of skeletal muscle mass and strength. The current study aimed to investigate the association between adherence to MIND diet and decrease the risk of age-associated poor muscle strength. This cross-sectional study was performed using data from Ravansar's non-communicable diseases (RaNCD) cohort study on 3181 adults (48.5% men) aged 35–65 years. The dietary intake of the studied participants was assessed by the use of a 114-item food frequency questionnaire (FFQ) developed by RaNCD cohort study. The MIND diet and the major dietary patterns were computed based on their dietary intake and three dietary patterns were identified including plant-based diet, high protein diet, and unhealthy diet. Hand grip strength (HGS) was measured using a hand-held hydraulic handgrip dynamometer and poor HGS was defined as HGS less than 32.8 and 20.5 kg in men and women, respectively. We found that greater adherence to MIND diet was associated with lower risk of poor HGS (OR: 0.65; CI 95%: 0.51-0.83). Furthermore, participants who were in third tertiles of plant- based and high protein diet were more likely 37% and 33% lower risk of poor HGS (OR: 0.63; CI 95%: 0.5-0.79), (OR: 0.67; CI 95%: 0.54-0.84), respectively. On the other hand, greater following to unhealthy diet was related to higher risk of poor HGS (OR: 1.39; CI 95%: 1.11-1.74). Overall, our findings provide that adhere to plant- based and high protein diet, as well as MIND diet had protective effects on age related poor HGS, while adherence to unhealthy diet can developed age related poor HGS.


2014 ◽  
Vol 116 (12) ◽  
pp. 1582-1592 ◽  
Author(s):  
Damien M. Callahan ◽  
Nicholas G. Bedrin ◽  
Meenakumari Subramanian ◽  
James Berking ◽  
Philip A. Ades ◽  
...  

Age-related loss of skeletal muscle mass and function is implicated in the development of disease and physical disability. However, little is known about how age affects skeletal muscle structure at the cellular and ultrastructural levels or how such alterations impact function. Thus we examined skeletal muscle structure at the tissue, cellular, and myofibrillar levels in young (21–35 yr) and older (65–75 yr) male and female volunteers, matched for habitual physical activity level. Older adults had smaller whole muscle tissue cross-sectional areas (CSAs) and mass. At the cellular level, older adults had reduced CSAs in myosin heavy chain II (MHC II) fibers, with no differences in MHC I fibers. In MHC II fibers, older men tended to have fewer fibers with large CSAs, while older women showed reduced fiber size across the CSA range. Older adults showed a decrease in intermyofibrillar mitochondrial size; however, the age effect was driven primarily by women (i.e., age by sex interaction effect). Mitochondrial size was inversely and directly related to isometric tension and myosin-actin cross-bridge kinetics, respectively. Notably, there were no intermyofibrillar or subsarcolemmal mitochondrial fractional content or myofilament ultrastructural differences in the activity-matched young and older adults. Collectively, our results indicate age-related reductions in whole muscle size do not vary by sex. However, age-related structural alterations at the cellular and subcellular levels are different between the sexes and may contribute to different functional phenotypes in ways that modulate sex-specific reductions in physical capacity with age.


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