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1.
《The Foot》2021
ObjectiveTo examine differences in lower limb muscle strength between older people with varying degrees of hallux valgus deformity.MethodsMuscle strength was measured at the knee, ankle and foot using hand-held dynamometry and a clinical test of toe strength (the paper grip test) in 157 older people (99 women and 58 men) aged 65 to 91 (mean 74.1, SD 5.9) years. Hallux valgus severity was documented as none, mild, moderate or severe using validated photographs. Differences in muscle strength according to hallux valgus severity were evaluated using analysis of variance, adjusting for age. Paper grip test performance was compared across the hallux valgus severity groups using the chi-square (χ2) statistic.ResultsKnee extension, ankle joint dorsiflexion, ankle joint plantar flexion, ankle joint inversion, ankle joint eversion and lesser toe plantarflexion strength were not significantly different across the four hallux valgus severity groups. However, there was a significant, dose-response reduction in hallux plantarflexion strength with increasing severity of hallux valgus. This persisted after adjustment for age (F3 = 5.5, p = 0.001) with a medium effect size (partial η2 = 0.10). The number of participants who could successfully complete the paper grip test of the hallux significantly reduced across the four hallux valgus categories (χ2 = 18.5, p < 0.001).ConclusionsThere is a specific and progressive reduction in hallux plantarflexion strength with increasing severity of hallux valgus in older people. This finding has potential implications for both the aetiology and treatment of this common and disabling condition. 相似文献
2.
Summary Eight men (20–23 years) weight trained 3 days week–1 for 19 weeks. Training sessions consisted of six sets of a leg press exercise (simultaneous hip and knee extension and ankle plantar flexion) on a weight machine, the last three sets with the heaviest weight that could be used for 7–20 repetitions. In comparison to a control group (n = 6) only the trained group increased (P<0.01) weight lifting performance (heaviest weight lifted for one repetition, 29%), and left and right knee extensor cross-sectional area (CAT scanning and computerized planimetry, 11%, P<0.05). In contrast, training caused no increase in maximal voluntary isometric knee extension strength, electrically evoked knee extensor peak twitch torque, and knee extensor motor unit activation (interpolated twitch method). These data indicate that a moderate but significant amount of hypertrophy induced by weight training does not necessarily increase performance in an isometric strength task different from the training task but involving the same muscle group. The failure of evoked twitch torque to increase despite hypertrophy may further indicate that moderate hypertrophy in the early stage of strength training may not necessarily cause an increase in intrinsic muscle force generating capacity. 相似文献
3.
Summary Methods in current practice for ascertaining time of death are largely based on the cooling of the body after death and are
somewhat unreliable. A theoretica relationship is known to exist between the decline in the properties defining nerve conduction
and time after death caused by the gradual cessation of metabolic activity in nerves. A number of such properties were measured
in rats during life and after death. In most cases the relationship was found to be inconsistent. The chronaxie of the strength
duration curve for the sciatic nerve was, however, found to increase consistently and reproducibly in a linear fashion over
the first 90 min after death to a plateau value which was maintained beyond 135 min. These findings are discussed as the possible
basis of a forensic method of determining the duration of the “post mortem interval” within the first few hours after death.
相似文献
4.
The purpose of the study was to compare the effect of voluntary pelvic floor muscle (PFM) contraction and vaginal electrical stimulation on urethral pressure. Twelve women with genuine stress incontinence, mean age 49.4 years (range 33–66) participated in the study. The urethral and bladder pressures were recorded simultaneously through a double-lumen 8 Ch catheter. The patients first performed three voluntary PFM contractions. Then two electrical stimulators, Conmax and Medicon MS 105, 50 Hz, were used in random order. A visual analog scale was used to measure pain and discomfort. Pain was reported to mean 6.8, SEM 0.64 (range 0.7–9.9) and mean 6.1, SEM 0.81 (range 0–9.1) with Conmax and Medicon MS 105, respectively. The mean paired difference in favor of voluntary contraction with Conmax was ?8.0, SD 6.7,P=0.0067, and with Medicon MS 105 it was ?12.2, SD 5.9,P=0.0022. The results demonstrated that voluntary PFM contraction increased urethral pressure significantly more than did vaginal electrical stimulation. 相似文献
5.
目的:探讨Estenia瓷树脂复合体的强度,并与其他几种树脂材料进行比较,为临床选择冠桥树脂材料提供参考。方法:采用Estenia瓷树脂复合体体外模拟下颌第一磨牙单冠和第一磨牙缺失3个单位固定桥的形态,测试单冠的抗压强度和固定桥的抗弯强度,并与Artglass、Solidex、Targis3种树脂材料在相同实验方法下测试得到的结果作比较。结果:Estenia瓷树脂单冠的折裂最大载荷均值为600.20N,Estenia瓷树脂桥的折裂最大载荷均值为302.53N。结论:Estenia瓷树脂复合体的强度高于Artglass﹑Solidex和Targis树脂复合体。 相似文献
6.
Twenty-five persons with diabetes (aged 55–83 years) who were living independently in the community, and 40 age- and sex-matched non-diabetic controls were assessed for tactile sensitivity, vibration sense, proprioception, quadriceps strength and body sway. In both men and women, those with diabetes performed significantly worse in tests of body sway on firm and compliant surfaces compared with the control subjects after controlling for weight and body mass index. The female diabetic subjects also performed significantly worse in tests of peripheral sensation and strength compared with controls. Age-related declines in sensori-motor function were greater in the diabetic group (r = 0.55–0.75) than in the controls (r < 0.44), while within the diabetic group, duration of diabetes and vibration sense were significantly correlated with sway on a compliant (foam rubber) surface with the eyes open (partial r = 0.52, p < 0.01 and r = 0.55, p < 0.01, respectively). The study findings provide evidence that older people with diabetes have problems with stability and related sensori-motor factors which may place them at increased risk of falls. 相似文献
7.
Portero P Bigard AX Gamet D Flageat JR Guézennec CY 《European journal of applied physiology》2001,84(6):540-546
The purpose of this study was to quantify the neuromuscular cervical adaptations to an 8 week strength training programme.
Seven healthy men, with no pathological conditions of the neck, performed a lateral flexion isometric resistance-training
programme three times a week. The training sessions consisted of one set of ten contractions, each of 6 s duration, at 60%
of the predetermined maximal voluntary isometric torque (MVTim) (warm-up) and two sets of eight contractions, each of 6 s duration, at 80% MVTim. The training effects were evaluated in three ways: muscle size, strength and fatigability. The cross-sectional areas (CSA)
of the trapezius (TRP) and sternocleidomastoideus (SCM) muscles were determined using a computerised tomographic scanner.
Results showed an increase in the CSA of TRP and SCM muscles after training, 8.8% at C5 level and 6.4% at C7 level for SCM
muscle and 12.2% at C7 level for TRP muscle. Strength increased significantly under both isometric and isokinetic conditions
(35% and 20%, respectively). Muscle fatigability in lateral flexion was quantified during a sustained isometric contraction
at 50% of MVTim. The shift of the mean power frequency of the electromyogram power spectrum density function of SCM muscle toward lower frequencies
was less after training (14.6% compared to 6.8%). These results indicate the beneficial effect of a strength-training programme
which increases neck muscle size and strength during lateral flexion, and decreases the fatigability of the superficial muscles
of the neck.
Electronic Publication 相似文献
8.
Summary The purpose of this study was to evaluate the effects of age on dynamic muscle attributes of the knee extensors and flexors in postmenopausal women. Young healthy women (3rd decade,n = 15; 4th decade,n = 5) and older healthy women (6th decade,n = 9; 7th decade,n = 6) were tested at six angular velocities from 60° · s–1 to 400° · s–1. The 3rd and 4th decade groups produced greater extensor and flexor values for strength related variables at all angular velocities (peak torque, angle specific torque, work, power) than both the 6th and 7th decade groups (P<0.05). However, relative changes in these variables, with increments in angular velocity, were equivalent among the groups. Analysis of the flexor: extensor ratios for these variables demonstrated a differential loss in flexor function with increased age, perhaps indicative of type II motor unit loss or muscle fibre atrophy. It is suggested that such changes may be present even within 4th decade subjects. 相似文献
9.
Muscle strength, volume and activation following 12-month resistance training in 70-year-old males 总被引:2,自引:2,他引:2
Morse CI Thom JM Mian OS Muirhead A Birch KM Narici MV 《European journal of applied physiology》2005,95(2-3):197-204
In elderly males muscle plantar flexor maximal voluntary contraction (MVC) torque normalised to muscle volume (MVC/VOL) is reduced compared to young males as a result of incomplete muscle activation in the elderly. The aim of the present study was to determine the influence of a 12-month resistance training programme on muscle volume, strength, MVC/VOL, agonist activation and antagonist coactivation of the plantarfexors in elderly males. Thirteen elderly males aged 70 years and over (range 70–82 years), completed a 12-month whole body resistance-training programme (TRN), training three times a week. Another eight males (range 18–30 years), who maintained their habitual physical activity for the same 12-month period as the TRN group acted as controls (CTRL). Isometric plantarflexor maximal voluntary contraction (MVC) torque increased in the TRN group by 20% (P<0.01), from 113.1±22.0 Nm to 141.5±19.2 Nm. Triceps surae volume (TS VOL) assessed using MRI, increased by 12%, from 796.3±78.9 cm3 to 916.8±144.4 cm3 . PF activation, measured using supramaximal double twitch interpolation, increased from 83.6±11.0% pre training, to 92.1±7.6% post training (P<0.05). Dorsiflexion MVC and antagonist coactivation (assessed using surface electromyography) did not change with training. Plantarflexor MVC torque normalized for triceps surae muscle volume (MVC/VOL) was 142.6±32.4 kN m–2 before training and 157.0± 27.9 kN m–2 after training (a non-significant increase of 8%). No significant change in any measurement was observed in the CTRL group. This study has shown that the gain in muscle strength in response to long-term (12-month) training in older men is mostly accounted for by an increased muscle volume and activation. 相似文献
10.
Wehrmeyer JA Barthel JA Roth JP Saifuddin T 《Medical & biological engineering & computing》1998,36(4):475-479
A testing device is developed that determines the stiffness, or flexural rigidity, of an endoscope at specific locations down
its length by subjecting it to a compressive axial force, a situation similar to the actual forces applied to the endoscope
during a clinical procedure. The endoscope is made to deform in a similar fashion to a slender buckled column and the force
causing this deformation is related to the flexural rigidity using column buckling theory. A direct relationship between the
critical load needed to cause buckling and the square of column length L is demonstrated experimentally and is expected theoretically,
giving confidence in the application of column buckling theory to endoscope testing. Additional confidence in the validity
of the columnbuckling test results is obtained by their similarity to data obtained by subjecting the endoscope to a transverse
load, determining deflection, and modelling the endoscope as a bent elastic beam. Several makes and models of endoscopes were
tested, with flexural rigidity values typically ranging between 160 to 240 Ncm2. The effect of a metal stiffener inserted in an endoscope's accessory channel is quantified, as is the change in flexural
rigidity down the insertion shaft of a graded-stiffness endoscope. Significant differences in flexural rigidity were obtained
between identical endoscopes, each sharing similar usage histories, indicating the need for flexural rigidity measurements
for each individual endoscope of a particular model line, though a more extensive study is required to reliably determine
scope-to-scope stiffness variations for a particular model line. 相似文献