BACKGROUND AND AIMS: The level of physical functioning (PF) late in life has, in recent years, been shown to be influenced by genetic factors. One of the most extensively studied genetic variants associated with PF and trainability is insertion/deletion (I/D) polymorphism in the gene encoding Angiotensin Converting Enzyme (ACE). However, ACE studies have mainly been conducted among younger persons in excellent physical shape. In this study, we examine whether the level of PF, trainability, or rate-of-change are associated with the ACE genotype among the elderly. METHODS: We used data from 4 randomized training studies of elderly Danes (N = 203). The measures of PF were self-report, maximal oxygen uptake, muscle strength, walking speed, and body composition. RESULTS: Overall, a favorable change in the measures of PF was observed in training groups compared with control groups. However, within groups, neither pre- or post-training/control period levels of PF nor differences in pre- and post-levels were associated with the ACE genotype. CONCLUSIONS: On the basis of our randomized studies, we could not detect any association between the ACE genotype and the level of PF or change, regardless of whether response to physical training or spontaneous changes was studied.
Prolonged occupational standing has previously been associated with low back pain (LBP) development. The immediate effects of a bout of prolonged standing on subsequent functional movement performance have not been investigated. It is possible that including a period of prolonged standing may have acute, detrimental effects. The purpose of the study is to investigate the impact of a prolonged standing exposure on biomechanical profiles (trunk muscle activation, joint stiffness and kinematics) during three functional movements. A total of 23 volunteers without history of LBP performed lumbar flexion, single-leg stance and unloaded squat movements pre- and post 2 h of standing exposure. It was found that 40% of the participants developed LBP during the standing exposure. There was a decrease in vertebral joint rotation stiffness in lateral bending and increased centre of pressure excursion during unilateral stance following standing exposure. There may be adverse effects to prolonged standing if followed by activities requiring precise balance or resistance of side loads. STATEMENT OF RELEVANCE: Prolonged standing may result in decreases in balance reactions during narrow base conditions as well as in the capacity to effectively resist side-loads at the trunk. Consideration should be given when prolonged standing is included in the workplace.
In sports, like team handball, fatigue has been associated with an increased risk of anterior cruciate ligament (ACL) injury. While effects of fatigue on muscle function are commonly assessed during maximal isometric voluntary contraction (MVC), such measurements may not relate to the muscle function during match play. The purpose of this study was to investigate the effect of muscle fatigue induced by a simulated handball match on neuromuscular strategy during a functional sidecutting movement, associated with the incidence of ACL injury. Fourteen female team handball players were tested for neuromuscular activity [electromyography (EMG)] during a sidecutting maneuver on a force plate, pre and post a simulated handball match. MVC was obtained during maximal isometric quadriceps and hamstring contraction. The simulated handball match consisted of exercises mimicking handball match activity. Whereas the simulated handball match induced a decrease in MVC strength for both the quadriceps and hamstring muscles (P
Clinical measures of seated postural control in adults are not standardized and most are derived from in-house tools. The purpose of this study is to adapt a pediatric instrument to evaluate seated postural control in adult wheelchair users.
The new instrument is called the Seated Postural Control Measure for Adults (SPCMA) 1.0. Five preliminary versions were pretested with some 20 adults by two raters and a group of experts.
This instrument comprises three sections: Section 1, level of sitting scale for adults (1 item, 7-point ordinal scale); Section 2, static postural alignment (22 items, 7-point ordinal scale); and Section 3, postural alignment after a dynamic activity, propulsion of the wheelchair on flat terrain and an incline (22 items, 7-point ordinal scale).
The SPCMA for Adults 1.0 improves the quality and uniformity of evaluations done by different raters, which facilitates more rigorous follow-up of clients over time, communication between professionals, and objective verification of the attainment of intervention objectives.
This investigation was designed to (a) develop an individualized mechanical model for measuring aerodynamic drag (F(d) ) while ski racing through multiple gates, (b) estimate energy dissipation (E(d) ) caused by F(d) and compare this to the total energy loss (E(t) ), and (c) investigate the relative contribution of E(d) /E(t) to performance during giant slalom skiing (GS). Nine elite skiers were monitored in different positions and with different wind velocities in a wind tunnel, as well as during GS and straight downhill skiing employing a Global Navigation Satellite System. On the basis of the wind tunnel measurements, a linear regression model of drag coefficient multiplied by cross-sectional area as a function of shoulder height was established for each skier (r > 0.94, all P
This study aimed to investigate whether milrinone effect on cardiac muscle contractility undergoes to age-related changes. Experiments were carried out on papillary muscles isolated from right ventricle of Brown Norway rats belonging to two different age groups: 2 month old and 18 month old. The effect of milrinone (10-100 microM) on rat cardiac muscle in vitro preparations was characterized by a reduction of peak developed tension and of contraction duration. Furthermore, the recovery of contractility after a contractile cycle, i.e. the mechanical restitution was faster in the presence of milrinone than in control conditions. All these effects were reduced in preparations from 18 month old rats compared to preparations from 2 month old rats. The decrease of milrinone effect on the mechanical restitution was particularly pronounced. The reduction of the milrinone effects is likely connected with the reduction of the maximal effect of adrenergic stimulation, although the molecular basis of this link is not yet clearly understood.
The aim of the present study was to evaluate age- and sex-related changes in the geometry parameters (metacarpal cortical index (MCI) and Breaking Bending Resistance Index [BBRI]) of long hand bones in a large Chuvashian cohort using cross-sectional and longitudinal study designs. The data were gathered in 1994 (557 individuals) and 2002 (513 individuals). The latter sample included 260 individuals who were studied only during the second expedition, and 253 individuals who were previously investigated in 1994. Statistical analyses included a maximum likelihood-based model-fitting technique and a t-test comparison. Our study describes age-related MCI and BBRI changes in both sexes from the age of 18 years to 84 years. At any age, the BBRI values were higher in males than in females, but MCI was greater in females than in males before age 50 and lower after that age. The study provides initial evidence of a secular trend in MCI and BBRI. In male hand bones, the cortex became relatively thicker and it better resisted bending and breaking in comparison to individuals born at the beginning of the 20th century. In females, the trend toward higher MCI values can be observed only in those born between 1936 and 1966 and the trend toward higher BBRI values stopped in 1950.
Disuse has been shown to cause a rapid and dramatic loss of skeletal mass and strength in the load-bearing bones of young and mature animals and humans. However, little is known about the skeletal effects of disuse in aged mammals. The present study was designed to determine whether the skeletal effects of disuse are maintained with extreme age. Fischer 344/Brown Norway male rats (6 and 32 mo old) were hindlimb suspended (HS) or housed individually for 2 wk. Trabecular volume and microarchitecture in the proximal tibia were significantly decreased by HS only in young rats. HS significantly reduced cortical bone mineral density and increased cortical porosity only in old rats by inducing new pore formation. Cortical pore diameter was also increased in old rats, regardless of loading condition. Ex vivo osteogenic and adipogenic cultures established from each group demonstrated that age and HS decreased osteoblastogenesis. Age, but not HS, decreased sensitivity to endogenous bone morphogenetic protein stimulation, as measured by treatment with exogenous Noggin. Adipocyte development increased with age, whereas HS suppressed sensitivity to peroxisome proliferator-activated receptor-gamma-induced differentiation. Serum insulin-like growth factor I levels were reduced with HS in young rats and with age in control and HS rats. These results suggest that the site of bone loss due to disuse is altered with age and that the loss of osteogenic potential with disuse in the old rats may be due to the combined effects of decreased insulin-like growth factor I levels and sensitivity, as well as diminished bone morphogenetic protein production.
Total knee arthroplasty (TKA) is associated with severe pain, and effective analgesia is essential for the quality of postoperative care and ambulation. The analgesic effects of adding an obturator nerve block (ONB) to a femoral triangle block (FTB) after TKA have not been tested previously. We hypothesized that combined ONB and FTB will reduce opioid consumption and pain compared with those of a single FTB or local infiltration analgesia (LIA).
Seventy-eight patients were randomized to combined ONB and FTB, single FTB, or LIA after primary unilateral TKA. The primary outcome was morphine consumption during the first 24 postoperative hours. Secondary outcomes included morphine consumption during the first 48 postoperative hours, pain at rest and passive knee flexion, nausea and vomiting, cumulated ambulation score, and Timed Up and Go test.
Seventy-five patients were included in the analysis. The total intravenous morphine consumption during the first 24 postoperative hours was 2 mg (interquartile range [IQR], 0-15) in the combined ONB and FTB group, 20 mg (IQR, 10-26) in the FTB group (P = 0.0007), and 17 mg (IQR, 10-36) in the LIA group (P = 0.002). The combined ONB and FTB group displayed reduced pain, nausea, and vomiting compared with the other groups. The ambulation tests showed no statistically significant differences between the groups.
Addition of ONB to FTB significantly reduced opioid consumption and pain after TKA compared with a single FTB or LIA, without impaired ambulation.
To review head injury in football through historical, anatomic, and physiological analysis.
We obtained data from a thorough review of the literature.
The reported incidence of concussion among high school football players dropped from 19% in 1983 to 4% in 1999. During the 1997 Canadian Football League season, players with a previous loss of consciousness in football were 6.15 times more likely to experience a concussion than players without a previous loss of consciousness (P