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Limited information of occupational injury statistics within academic settings exists. Universities and colleges are an important and insightful work environment due to the varied nature of the work performed by employee groups. The objective of this study was to describe occupational injuries for all work groups in a large research intensive university. A retrospective database analysis was conducted on 2029 employee incident reports over a five year period (2000-2004) to determine general and departmental prevalence of injury types, locations, and mechanisms. Demographic analysis revealed an average age of 42 years and 9 years of work experience. Overall, the most frequent injuries were to the hand (40%), were musculoskeletal in nature (42%), and resulted from being 'struck or contacted by' (33%). The greatest number of incidents occurred in food services, followed by physical plant and staff services. Closer examination of incidents reported by food services indicated 53% of injuries occurred to the hand and 72% required first aid. Notable too was that 19% of physical plant injuries occurred to the back, but these reports accounted for 40% of total back injuries and 50% of all lost time claims in the total database. Further epidemiological research in academic institutions is needed to better understand the inherent injury risk in this work sector. [ABSTRACT FROM AUTHOR]

Research into the causes of osteoarthritis (OA) of the knee has traditionally followed a biomedical approach whereby the disease development and progression is regarded as an internal physiological process. As a result, treatment has focused on symptom reduction with limited modification of psychosocial variables. In fact, psychosocial factors such as environment and employment play a substantial role in the disease process and are important determinants of the overall level of disability of affected individuals. Thus, by placing greater importance on the biomedical aspects of knee OA, a complete representation of the health condition cannot be achieved thereby limiting treatment effectiveness. The purpose of this clinical commentary is to provide a rationale for the implementation of a biopsychosocial model of knee OA that can aid in more effective research and treatment for the disorder. [ABSTRACT FROM AUTHOR]

BACKGROUND: Hemiplegic shoulder pain is common after stroke causing hemiplegia. It adversely affects the recovery of arm function and independence in activities of daily living. Subluxation, abnormal tone and limited range of motion or capsular constrictions have been reported as potential causes. Other factors such as rotator cuff tears, brachial plexus injury, shoulder-hand syndrome and other pre-existing pathological conditions may also be associated with hemiplegic shoulder pain. The etiology remains unclear, but hemiplegic shoulder pain may result from a combination of the above factors. SCOPE: This literature review examines the possible causes of hemiplegic shoulder pain and discusses the implications for occupational therapy treatment. Occupational therapy interventions include proper positioning, facilitation of movement through purposeful therapeutic activities, increasing passive range of motion, implementation of external supports and treatment of shoulder-hand syndrome. PRACTICE IMPLICATIONS: Understanding the processes involved will assist with effective assessment, treatment and prevention of hemiplegic shoulder pain. This will facilitate clients' participation in rehabilitation programs and move them towards attainment of optimal function. [ABSTRACT FROM AUTHOR]

Background and Purpose. The purpose of this study was to quantify several variables of ankle stiffness and dorsiflexion (DF) range of motion (ROM) in the casted (fractured) and noncasted ankles of humans after cast removal. Subjects. Thirty subjects (chi square age = 32.4 years, SD=15.8) with malleolar ankle fractures were tested within 4 days of cast removal but before they began physical therapy. Methods. A torque motor system generated torque-versus-displacement graphs by recording angular displacement and resistive torque during a 6 degree/s passive cycling of the ankle from 10 degrees of plantar flexion to the limit of DF ROM. Maximum passive DF ROM, passive torque, and passive elastic stiffness at the neutral position and energy loss were measured. Testing was performed in the absence of triceps surae muscle electromyographic activity. For analysis, subjects were separated into two groups based on fracture severity. Results. There was no difference in passive torque between the fractured ankles and the matched noncasted ankles. There was a small difference in passive elastic stiffness between the more severely fractured ankles and the matched noncasted ankles. The fractured ankles were different in terms of energy loss from the matched noncasted ankles. For maximum passive DF ROM, there was a large difference between the fractured ankles (more severe: chi square = 4.4 degrees; less severe: chi square = 6.8 degrees) and the matched noncasted ankles (more severe: chi square = 15.1 degrees; less severe: chi square =19.1 degrees). Conclusion and Discussion. Altered length-tension relationships and neuromuscular mechanisms have been suggested to produce postimmobilization joint contractures. The results of this study on humans are consistent with both possibilities and support the theory that changes that occur during immobilization result in protection from overstretching of the fragile calf musculature after a period of ankle fixation. The time course of normalization of stretch reflexes warrants investigation. [ABSTRACT FROM AUTHOR]

This study quantifies concentric and eccentric dorsiflexor muscle torque at various movement velocities and determines the neuromuscular effects from short-term practice of repeated maximal voluntary contractions using an isokinetic resisted exercise program in older adults. Twenty-eight subjects (76.3+/-4.6 years) trained concentric and eccentric dorsiflexion 3 days per week for 2 weeks at 30 degrees, 90 degrees, and 180 degrees/s through 40 degrees of dorsiflexion range of motion. Peak torque, rate of torque development, surface electromyography, and strength curves at each velocity were compared before and after training. Increases were found for concentric (27%) and eccentric (20%) dorsiflexor peak torque and concentric rate of torque production (20%-53%) across all movement velocities (p < .01). Training also significantly increased dorsiflexor concentric (64%) and eccentric (55%) surface electromyography; taken together, this is evidence of apparent adaptation of neural factors in older adults with short-term training. These findings support that eccentric and concentric strength training enhances the control and production of ankle muscle dorsiflexor torque in older adults, with implications for improving functional mobility of the ankle joint. [ABSTRACT FROM AUTHOR]

Heart rate (HR), mean arterial blood pressure (MAP), and rate-pressure product (RPP) responses to submaximal isokinetic concentric (CON) and eccentric (ECC) knee extension exercise were compared at the same absolute torque output in 20 young (mean+/-SD=23.2+/-1.7 years) and 20 older (mean+/-SD=75.2+/-4.6 years) adults. After determination of peak CON and ECC torques, subjects performed separate, randomly ordered, 2-minute bouts of isokinetic CON and ECC exercise (90 degrees/s, exercise intensity: 50% of CON peak torque). CON exercise elicited greater changes in HR, MAP, and RPP than ECC exercise (p<.001) for both age groups. There were no age-related differences in HR, MAP, or RPP responses for either CON or ECC exercise. At the same absolute torque output, isokinetic CON knee extension exercise elicited significantly greater increases in cardiovascular stress than ECC exercise in both young and older adults. This result has implications for determining appropriate fitness and rehabilitation programs. [ABSTRACT FROM AUTHOR]

Older adults better maintain eccentric strength relative to isometric strength, as indicated by a higher ratio of eccentric:isometric torque as compared with younger adults. The effect of increasing angular velocities (>200°/s) on the age-related maintenance of eccentric strength has not been tested and thus it is unknown whether the eccentric:isometric ratio is velocity dependent in old age. The purpose of this study was to investigate eccentric strength of the ankle dorsiflexors over a large range of lengthening angular velocities in young and older men. Isometric neuromuscular properties were assessed on a HUMAC NORM dynamometer. Nine young (∼24 years) and 9 older (∼76 years) healthy men performed maximal voluntary eccentric contractions at angular velocities of 15-360°/s. Despite near full voluntary activation (>95%), the older men were ∼30% weaker than the young men for isometric strength (P < 0.05). Across all lengthening velocities, older men had a greater eccentric:isometric ratio than young men (P < 0.05). Additionally, there was a velocity dependence of strength in both young and older men: eccentric strength increased as velocity increased up to 120°/s (P < 0.05) and plateaued thereafter. In young and older men, eccentric strength at 15°/s was ∼20% and ∼40% greater than isometric strength (P < 0.05), while at 360°/s eccentric strength was ∼50% and ∼90% greater, respectively (P < 0.05). These findings indicate that with increasing angular velocity, both young and older men have considerable increases in the eccentric:isometric ratio of torque production.

Golf is a popular sport with both perceived and real health benefits. However, certain injury risks are also prevalent, particularly to the lower back. Epidemiological studies have shown that lower back pain (LBP) from golf account for between 18% and 54% of all documented ailments, leading many researchers to regard the condition as the most common golf injury. The purpose of this review was to examine the scientific literature to ascertain the risk factors associated with the development of LBP from playing golf and suggest methods to modify or limit these factors. Results of the review indicate that the high frequency of LBP appears multi-factorial although the asymmetrical and forceful nature of the swing along with excessive play and practice, particularly amongst elite players, appear to be common factors. Other factors include swing flaws leading to excessive side-bend and over-rotation of the spine, abnormal muscle recruitment, poor trunk endurance, restricted lead hip internal rotation and the use of unnecessarily stressful club transportation methods. Methods to help control or eliminate excessive stress on the lower back would include reducing the amount spent playing or practicing, seeking professional assistance to assess and adjust swing mechanics, improve trunk and hip flexibility, increase the strength and endurance of the trunk musculature, consider different footwear options and avoid carrying the golf bag. Adopting some or all of these recommendations should allow players to continue to enjoy the sport of golf well into their senior years.

Following active muscle shortening, the steady-state isometric torque at the final muscle length is lower than the steady-state torque obtained for a purely isometric contraction at that same final muscle length. This well-documented property of skeletal muscle is termed shortening-induced torque depression (TD). Despite many investigations into the mechanisms of weakness and power loss in old age, the influence of muscle shortening on the history dependence of isometric torque production remains to be elucidated. Thus, it is unclear whether older adults are disadvantaged for torque and power production following a dynamic shortening contraction. The purpose of this study was to evaluate shortening-induced TD in older adults, and to determine whether shortening-induced TD is related to power loss. Maximal voluntary isometric dorsiflexion contractions (MVC; 10s) in 8 young (25.5±3.7years) and 9 old (76.1±5.4years) men were performed on a HUMAC NORM dynamometer as a reference, and then again following an active shortening of 40° joint excursion (40°PF-0°PF) at angular velocities of 15°/s and 120°/s. Work and instantaneous power were derived during shortening. Shortening-induced TD was calculated and expressed as a percentage by determining the mean torque value over 1s during the isometric steady state of the MVC following shortening, divided by the mean torque value for the same 1s time period during the isometric reference MVC. To assess muscle activation, electromyography (root mean square; EMGRMS) of the tibialis anterior (TA) and soleus (SOL) was calculated at identical time points used in assessing shortening-induced TD, and voluntary activation (VA) was assessed using the interpolated twitch technique. Old were 18% weaker than young for MVC, and ~40% less powerful for 15°/s and 120°/s of shortening. Old produced 37% and 21% less work for 15°/s and 120°/s than young, respectively. Furthermore, old experienced 60% and 70% greater shortening-induced TD than young for 15°/s and 120°/s, respectively with similar EMGRMS and VA across all conditions. A significant relationship between shortening-induced TD and instantaneous power was found only at the fast angular velocity for both the old (R(2)=0.32) and young (R(2)=0.45) men. The older men experienced greater shortening-induced TD than young while maintaining similar levels of voluntary activation. This previously unaccounted for history-dependent property of muscle may provide insight into power loss in old age., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Human adult aging is associated with a loss of strength, contractile velocity and hence, power. The principal plantar flexors, consisting of the bi-articular gastrocnemeii and the mono-articular soleus, appear to be affected differently by the aging process. However, the age-related effect of knee joint angle on the torque-angular velocity relationship and power production of this functionally important muscle group is unknown. The purpose was to determine whether flexing the knee, thereby reducing the gastrocnemius contribution to plantar flexion, would exacerbate the age-related decrements in plantar flexion power, or shift the torque-angular velocity relationship differently in older compared with young men. Neuromuscular properties were recorded from 10 young (~25 y) and 10 old (~78 y) men with the knee extended (170°) and flexed (90°), in a randomized order. Participants performed maximal voluntary isometric contractions (MVCs), followed by maximal velocity-dependent shortening contractions at pre-set loads, ranging from 15 to 75% MVC. The young men were ~20-25% stronger, ~12% faster and ~30% more powerful than the old for both knee angles (P<0.05). In both age groups, isometric MVC torque was ~17% greater in the extended than flexed knee position, with no differences in voluntary activation (>95%). The young men produced 7-12% faster angular velocities in the extended knee position for loads ≤30% MVC, but no differences at higher loads; whereas there were no detectable differences in angular velocity between knee positions in the old across all relative loads. For both knee angles, young men produced peak power at 43.3±9.0% MVC, whereas the old men produced peak power at 54.8±7.9% MVC. These data indicate that the young, who have faster contracting muscles compared with the old, can rely more on velocity than torque for generating maximal power., (Copyright © 2014. Published by Elsevier Inc.)

Following repetitive lengthening contractions, power (the product of torque and velocity) is impaired during shortening contractions. However, the relative contribution of each component to power loss and the underlying factors are unclear. We investigated neuromuscular properties of the dorsiflexors in 8 males (27 ± 3 years) and 8 females (26 ± 4 years) for a potential sex-related difference before, during, and after 150 unaccustomed maximal lengthening actions. Velocity-dependent power was determined from shortening contractions at 8 levels (1 N · m to 70% of maximum voluntary isometric contraction (MVC)) before, after, and throughout recovery assessed at 0-30 min, 24 h, and 48 h. Immediately following task termination, both sexes displayed similar impairments of 30%, 4%, and 10% in MVC torque, shortening velocity, and overall peak power, respectively (P < 0.05). Peak rate of isometric torque development (RTD) was reduced by 10% in males, but females exhibited a 35% reduction (P < 0.05). Rate of torque development for the MVC remained depressed in both sexes throughout the 30 min recovery period; however, the RTD returned to normal by 24 h in males but did not recover by 48 h in females. Power was reduced preferentially at higher loads (i.e., 60% MVC), with a greater loss in females (65%) than males (45%). For lower loads (<20% MVC), power was impaired minimally (4%-8%; P < 0.05) and recovered within 30 min in both groups. The reduction in maximal angular velocity persisted until 30 min of recovery, and peak power did not recover until 24 h for both sexes. Unaccustomed lengthening contractions decreased power preferentially at higher loads, whereas peak power was reduced minimally owing to maintenance of maximal shortening velocity.

The purpose of this project is to conduct a comprehensive and systematic scoping review to identify and document the breadth of literature related to physical activity-related injuries in older adults. The population of interest was adults (both males and females) over the age of 65 years, participating in exercise, leisure-time, or sport-type physical activities. The initial search yielded 16,828 articles, with 43 articles ultimately included. The final 43 articles utilized the following study designs: three experimental (two randomized control and one non-randomized control), 14 prospective studies, and 26 retrospective. The results of this scoping review would suggest that it may be premature to provide definitive incidence rates, causes, and correlates of physical activity-related injuries in older adults. However, the current literature does not suggest that older adults are at an increased risk of injury from participation in physical activities. Future research should utilize a consistent definition of 'injury' and consistent and comprehensive descriptors of injuries--including intensity level of engagement of activity and burden/severity of injury. In addition, injury rates in specific populations are needed, particularly for the oldest-old, for those in assisted-living situations, and for subgroups with clinical conditions. Finally, greater surveillance and documentation of older adult initiatives and interventions are needed in order to identify programs successful in reducing the injury rates of their target populations.

Triceps surae function can be modified by changes in knee joint angle through altering the effective contribution of the bi-articular gastrocnemeii. However, the impact on plantar flexor power from altering knee angle has not been studied systematically across a range of loads. Here, in 11 young men (25.7 ± 2.2 years), we determine the effect of knee angle on torque, velocity and power at loads ranging from 15 to 75 % maximal voluntary isometric contraction (MVC). Contractile properties were recorded with either the knee extended (170º) or flexed (90º). Despite similar voluntary activation (~97 %), peak twitch and MVC torques were 25 and 16 % lower in the flexed than extended knee (P < 0.05), respectively. Across all loads, subjects were 15-24 % less powerful with the knee flexed than extended (P < 0.05). In the flexed knee at relative loads ≤30 % MVC, impaired power was accompanied by 6-9 % slower shortening velocities than the extended knee. However, for the higher loads, limited torque production in the flexed knee was the key factor contributing to the generation of maximal power than for the extended position. This was supported by no change in velocity at higher loads (>30 % MVC) and a 15-22 % lower maximal rate of torque development across all loads. Hence, in a flexed knee position, which disadvantages the contribution of the gastrocnemeii, results in a left-downward shift in the torque-power relationship impairing maximal power production. Thus, the gastrocnemeii are not only a major contributor to plantar flexion torque, but also critical for modifying loaded shortening velocity and ultimately power production.

In older adults, isometric force production is enhanced following a voluntary lengthening contraction when compared with isometric force produced at the same muscle length without a prior lengthening contraction. This phenomenon is termed residual force enhancement (RFE), and appears to be related to the age-related maintenance of eccentric (ECC) strength. However, it is unknown whether age-related changes in muscle architecture contribute to greater RFE at short and long muscle lengths in old age. Neuromuscular properties of the knee extensors were assessed on a HUMAC NORM dynamometer. Torque was examined in young (26 ± 3 year, n = 11) and old men (77 ± 6 year, n = 11) during brief maximal voluntary isometric contractions (MVC) at 80° and 120° (180° representing full knee extension) and then compared with torque during a steady-state phase at the same joint angle following a maximal voluntary lengthening contraction at 30°/sec over a 60° joint excursion; either from 140 to 80° (long), or from 180 to 120° (short). Ultrasound images were obtained from the vastus lateralis during the isometric phase for each condition. When comparing the ECC torque with the MVC isometric torque, old men had 17% greater ECC:MVC ratios than young men, confirming an age-related maintenance of ECC strength. The extent of RFE was greater at long versus short but independent of age. At rest, old had shorter (∼18%) and less pennated (∼22%) fascicles. However, changes in fascicle length and pennation during contraction did not contribute to RFE in either group. Thus, age-related changes in muscle architecture may not contribute to RFE.

Maintaining and increasing walking speed in old age is clinically important because this activity of daily living predicts functional and clinical state. We reviewed evidence for the biomechanical mechanisms of how strength and power training increase gait speed in old adults. A systematic search yielded only four studies that reported changes in selected gait biomechanical variables after an intervention. A secondary analysis of 20 studies revealed an association of r(2)=0.21 between the 22% and 12% increase, respectively, in quadriceps strength and gait velocity in 815 individuals age 72. In 6 studies, there was a correlation of r(2)=0.16 between the 19% and 9% gains in plantarflexion strength and gait speed in 240 old volunteers age 75. In 8 studies, there was zero association between the 35% and 13% gains in leg mechanical power and gait speed in 150 old adults age 73. To increase the efficacy of intervention studies designed to improve gait speed and other critical mobility functions in old adults, there is a need for a paradigm shift from conventional (clinical) outcome assessments to more sophisticated biomechanical analyses that examine joint kinematics, kinetics, energetics, muscle-tendon function, and musculoskeletal modeling before and after interventions., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Background. Primary osteoarthritis of the elbow is a debilitating disease with an overall incidence of about 2%. Pain and reduced motion (ROM) lead to disability and loss of functional independence. Purpose. To critically review the literature on patient-related important functional outcomes (pain, ROMs and functional recovery) after surgery for primary OA of the elbow, utilizing the 2011 OCEBM levels of evidence. Design. A literature synthesis. Results. Twenty-six articles satisfied the inclusion and exclusion criteria; 25 of the studies were at level IV evidence, and 1 at level III. All three surgical techniques led to improvement in pain, ROM, and functional recovery in the short- and medium-term follow-up. Long-term follow-up results, available only for open joint debridement, showed recurrence of osteoarthritic signs on X-ray with minimal loss of motion. Recently, there seems to be an increased focus on arthroscopic debridement. Conclusion. The quality of research addressing surgical interventions is very low, including total elbow arthroplasty (TEA). However, the evidence concurs that open and arthroscopic joint debridement can improve function in patients with moderate-to-severe OA of the elbow. TEA is reserved for treating severe joint destruction, mostly for elderly individuals with low physical demands when other intervention options have failed.

Unlabelled: A contributing factor to the loss of muscle mass and strength with adult aging is the reduction in the number of functioning motor units (MUs). Recently, we reported that lifelong competitive runners (master runners = ~66 yr) had greater numbers of MUs in a leg muscle (tibialis anterior) than age-matched recreationally active controls. This suggested that long-term exposure to high levels of physical activity may limit the loss of MU numbers with adult aging. However, it is unknown if this finding is the result of long-term activation of the specifically exercised motoneuron pool (i.e., tibialis anterior) or an overall systemic neuroprotective effect of high levels of physical activity., Purpose: The purpose was to estimate the number of functioning MUs (MUNEs) in the biceps brachii (an upper body muscle not directly loaded by running) of nine young (27 ± 5 yr) and nine old (70 ± 5 yr) men and nine lifelong competitive master runners (67 ± 4 yr)., Methods: Decomposition-enhanced spike-triggered averaging was used to measure surface and intramuscular EMG signals during elbow flexion at 10% of maximum voluntary isometric contraction., Results: Derived MUNEs were lower in the biceps brachii of runners (185 ± 69 MUs) and old men (133 ± 69 MUs) than the young (354 ± 113 MUs), but the old and master runners were similar., Conclusions: Although there were no significant differences in MUNE between both older groups in the biceps brachii muscle, with the number of subjects tested here, we cannot eliminate the possibility of some whole-body neuroprotective effect. However, when compared with the remote biceps muscle, a greater influence on age-related spinal motoneuron survival was found in a chronically activated MN pool specific to the exercised muscle.

During lengthening of an activated skeletal muscle, the force maintained following the stretch is greater than the isometric force at the same muscle length. This is termed residual force enhancement (RFE), but it is unknown how muscle damage following repeated eccentric contractions affects RFE. Using the dorsiflexors, we hypothesised muscle damage will impair the force generating sarcomeric structures leading to a reduction in RFE. Following reference maximal voluntary isometric contractions (MVC) in 8 young men (26.5±2.8y) a stretch was performed at 30°/s over a 30° ankle excursion ending at the same muscle length as the reference MVCs (30° plantar flexion). Surface electromyography (EMG) of the tibialis anterior and soleus muscles was recorded during all tasks. The damage protocol involved 4 sets of 25 isokinetic (30°/s) lengthening contractions. The same measures were collected at baseline and immediately post lengthening contractions, and for up to 10min recovery. Following the lengthening contraction task, there was a 30.3±6.4% decrease in eccentric torque (P<0.05) and 36.2±9.7% decrease in MVC (P<0.05) compared to baseline. Voluntary activation using twitch interpolation and RMS EMG amplitude of the tibialis anterior remained near maximal without increased coactivation for MVC. Contrary to our hypothesis, RFE increased (∼100-250%) following muscle damage (P<0.05). It appears stretch provided a mechanical strategy for enhanced muscle function compared to isometric actions succeeding damage. Thus, active force of cross-bridges is decreased because of impaired excitation-contraction coupling but force generated during stretch remains intact because force contribution from stretched sarcomeric structures is less impaired., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Compared with isometric and dynamic velocity-constrained (isokinetic) tasks, less is known regarding velocity-dependent (isotonic) muscle power and recovery in older adults following repeated fatiguing lengthening contractions. We investigated voluntary and evoked neuromuscular properties of the dorsiflexors in nine old (68.3 ± 6.1 years) and nine young women (25.1 ± 1.3 years) during and following 150 lengthening contractions for up to 30 min of recovery. At baseline, the old were ~21% weaker for maximum isometric voluntary contraction (MVC) torque (P < 0.05), ~21% slower for peak loaded shortening velocity (P < 0.05), and ~39% less powerful compared with the young (P < 0.05). Following the task, MVC torque was depressed equally (~28%) for both groups (P < 0.05), but power was reduced ~19% in the old and only ~8% in the young (P < 0.05). Both measures remained depressed during the 30-min recovery period. Peak twitch torque (P (t)) was ~50% lower in the old at task termination, whereas the young were unchanged. However, by 5 min of recovery, P (t) was reduced similarly (~50%) in both groups, and neither recovered by 30 min. The old were affected more by low-frequency torque depression than the young, as shown by the ~40% and ~20% decreases in the stimulated 10:50 Hz ratio at task termination respectively, whereas both groups were affected similarly (~50%) 5 min into recovery, and neither recovered by 30 min. Thus, the coexistence of fatigue and muscle damage induced by the repetitive lengthening contractions impaired excitation-contraction coupling and cross-bridge function to a greater extent in the old, leading to a more pronounced initial loss of power than the young for up to 10 min following the exercise However, power remained blunted in both groups during the 30-min recovery period. These results indicate that older women are more susceptible to power loss than young following lengthening contractions, likely owing to a greater impairment in calcium kinetics.

Purpose: Determine which PA assessment tools are most closely related to frailty and whether PA is different across levels of frailty., Methods: Fifty community-dwelling Greek older women (63-90 years) participated in this study. PA was measured objectively over 10h using an accelerometer, a heart rate (HR) monitor, a portable electromyography (EMG) unit, and a global positioning system (GPS) and subjectively using the short version of the Minnesota Leisure Time Activity Questionnaire (MLTAQ). Participants were divided into three tertiles based on level of frailty as calculated from a Frailty Index (FI): low FI group (<0.17 FI); intermediate FI group (0.17-0.38 FI); and high FI group (>0.38 FI)., Results: Accelerometer step counts had the strongest correlation with frailty and were different across levels of frailty. The percentage of time engaged in PA was 31±15% when PA was determined using an accelerometer. Forty-five percent of the variability in the FI was explained by a combination of PA assessment tools including; accelerometer, EMG, GPS, and MLTAQ. The individual contribution of EMG determined activity from the biceps brachii (BB) to the FI prediction was 16%. Accelerometer contributed an additional 10% and time engaged in PA, as assessed with the MLTAQ, added an additional 6% to the prediction of FI score., Conclusions: PA assessment tools, when used in combination, provide important information about the PA accumulation of older women across levels of frailty., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Objective. This paper analyzes the effects of resistance training (RT) on metabolic, neuromuscular, and cardiovascular functions in older adults (mean age ≥ 65 years) with type 2 diabetes (T2DM). Research Design and Methods. A systematic review conducted by two reviewers of the published literature produced 3 records based on 2 randomized controlled trials that assessed the effect of RT on disease process measures and musculoskeletal/body composition measures. Statistical, Comprehensive Meta-Analysis (version 2) software was used to compute Hedge's g, and results were calculated using the random effects model to account for methodological differences amongst studies. Results. Largest effect of RT was seen on muscle strength; especially lower body strength, while the point estimate effect on body composition was small and not statistically significant. The cumulative point estimate for the T2DM disease process measures was moderate and statistically significant. Conclusions. RT generally had a positive effect on musculoskeletal, body composition, and T2DM disease processes measures, with tentative conclusions based on a low number of completed RCTs. Thus, more research is needed on such programs for older adults (≥65 years) with T2DM.

Older adults are less fatigable than young during isometric tasks, but this apparent ability to resist fatigue is often abolished when dynamic actions are performed. These findings could indicate that the velocity component of dynamic contractions or the task performed is an important factor in explaining fatigability of older adults. However, it has not been evaluated systematically. The purpose was to investigate the differences in age-related fatigue of the knee extensors in 8 older (73.6±3.5 years) and 8 younger (25.1±2.6 years) men. Neuromuscular measures were collected at baseline, during and immediately following task termination of three different maximal effort knee extension tasks. On three separate days, participants performed either 30 slow (1.05 rad·s(-1), 60°·s(-1)) or 30 moderate (3.14 rad·s(-1), 180°·s(-1)) isovelocity contractions, or 30 fast unconstrained velocity contractions with a fixed resistance (i.e., 20% maximal voluntary isometric contraction). At baseline, the older men were 25% and 35% less powerful than the younger men for the slow and moderate isovelocity tasks, respectively, but 42% less for the fast unconstrained velocity protocol. At task termination for the slow (old: 53%, young: 53%) and moderate (old: 45%, young: 38%) isovelocity fatigue tasks, power was reduced similarly in both age groups. However, for the fast unconstrained velocity task, power was reduced by a greater extent in older (35%) than the younger men (23%) at task termination. These results highlight that age-related impairments in voluntary shortening velocity exacerbate reductions in power production during repetitive dynamic tasks. Furthermore, the importance of this factor is masked when velocity is constrained (isovelocity) and fatigue is dependent primarily upon slow torque generation., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Background. As indicated in a recent systematic review relating to Canada's Physical Activity Guidelines for Older Adults, exercise interventions in older adults can maintain or improve functional abilities. Less is known about the role of flexibility in the maintenance or improvement of functional abilities, and there currently does not exist a synthesis of the literature supporting a consensus on flexibility training prescription. Purpose. To systematically review the effects of flexibility-specific training interventions on measures of functional outcomes in healthy older adults over the age of 65 years. Methods. Five electronic databases were searched for intervention studies involving concepts related to aging, flexibility, functional outcomes, and training interventions. After evaluating the articles for relevance, 22 studies were considered. Results. The results suggested that while flexibility-specific interventions may have effects on range of motion (ROM) outcomes, there is conflicting information regarding both the relationship between flexibility interventions and functional outcomes or daily functioning. Conclusions. Due to the wide range of intervention protocols, body parts studied, and functional measurements, conclusive recommendations regarding flexibility training for older adults or the validity of flexibility training interventions as supplements to other forms of exercise, or as significant positive influences on functional ability, require further investigation.

Despite an age-related loss of voluntary isometric and concentric strength, muscle strength is well maintained during lengthening muscle actions (i.e., eccentric strength) in old age. Additionally, in younger adults during lengthening of an activated skeletal muscle, the force level observed following the stretch is greater than the isometric force at the same muscle length. This feature is termed residual force enhancement (RFE) and is believed to be a combination of active and passive components of the contractile apparatus. The purpose of this study was to provide an initial assessment of RFE in older adults and utilize aging as a muscle model to explore RFE in a system in which isometric force production is compromised, but structural mechanisms of eccentric strength are well-maintained. Therefore, we hypothesised that older adults will experience greater RFE compared with young adults. Following a reference maximal voluntary isometric contraction (MVC) of the dorsiflexors in 10 young (26.1 ± 2.7 y) and 10 old (76.0 ± 6.5 y) men, an active stretch was performed at 15°/s over a 30° ankle joint excursion ending at the same muscle length as the reference MVCs (40° of plantar flexion). Any additional torque compared with the reference MVC therefore represented RFE. In older men RFE was ~2.5 times greater compared to young. The passive component of force enhancement contributed ~37% and ~20% to total force enhancement, in old and young respectively. The positive association (R(2) = 0.57) between maintained eccentric strength in old age and RFE indicates age-related mechanisms responsible for the maintenance of eccentric strength likely contributed to the observed elevated RFE. Additionally, as indicated by the greater passive force enhancement, these mechanisms may be related to increased muscle series elastic stiffness in old age.

The purpose of this study was to determine which performance measures of physical function are most closely related to frailty and whether physical function is different across levels of frailty. Fifty-three community-dwelling Greek women (63-100 years) participated in this study. Participants were divided into 3 tertiles based on level of frailty as calculated from a frailty index (FI): lowest FI group (<0.19 FI), intermediate FI group (0.19-0.36 FI), and highest FI group (>0.36 FI). Performance measures tested were handgrip and knee extension muscle strength and fatigue, upper and lower body muscular endurance, walking performance, agility, and dynamic balance. The greatest proportion of variance in the FI was explained by combining all performance-based measures of physical function. The performance measures that were most closely related to frailty yet different across levels of frailty were ambulatory mobility, lower body muscular endurance, and nondominant handgrip strength. Walking at a preferred pace had the strongest relationship to frailty rather than walking at maximal pace. Grip strength of the nondominant hand had a stronger correlation with frailty compared with the dominant hand. The FI was a better predictor of physical function than chronological age. The decline in physical function accelerated after the intermediate FI tertile. Definitions of frailty need to combine performance-based measures that can identify impairments in various domains of physical function. The assessment protocols of these measures are important.

The determination of power using isokinetic testing has been shown to be highly reliable. However, isotonic and isokinetic testing involve specific mechanical constraints that likely necessitate different neuromuscular strategies. Therefore, the purpose here was to establish test-retest intrarater reliability (separated by 7 days) of loaded maximal shortening velocity and velocity-dependent power of the ankle dorsiflexors using the isotonic mode of the Biodex dynamometer (i) at baseline and (ii) throughout recovery following 150 high-intensity lengthening contractions. Intraclass correlation coefficients (ICC)(2,1) with 95% CIs were used to determine relative reliability, whereas absolute reliability included typical error (TEM) and typical error expressed as a coefficient of variation (TEM(CV)). Twenty-four young men and women volunteered for the study. Maximal shortening velocity and power were determined with a fixed resistance set at 20% of maximal voluntary isometric contraction across 2 testing sessions separated by 7 days. ICCs were 0.93 and 0.98 for maximal shortening velocity and peak power, respectively. Following the lengthening contractions, ICCs indicated high reliability for maximal shortening velocity and peak power, 0.86 and 0.94, respectively, suggesting that a similar amount of fatigue was incurred on both days. Measures of absolute reliability for maximal shortening velocity and peak power also yielded high reliability. The isotonic mode is highly reliable when testing velocity-dependent power of the ankle dorsiflexors at baseline and following fatiguing lengthening contractions. The high reliability of this measure is encouraging and suggests that the isotonic mode can be used in various settings to track group changes before and after training and following fatigue and lengthening contractions.

This systematic review examines the effectiveness of current exercise interventions for the management of frailty. Eight electronic databases were searched for randomized controlled trials that identified their participants as "frail" either in the title, abstract, and/or text and included exercise as an independent component of the intervention. Three of the 47 included studies utilized a validated definition of frailty to categorize participants. Emerging evidence suggests that exercise has a positive impact on some physical determinants and on all functional ability outcomes reported in this systematic review. Exercise programs that optimize the health of frail older adults seem to be different from those recommended for healthy older adults. There was a paucity of evidence to characterize the most beneficial exercise program for this population. However, multicomponent training interventions, of long duration (≥5 months), performed three times per week, for 30-45 minutes per session, generally had superior outcomes than other exercise programs. In conclusion, structured exercise training seems to have a positive impact on frail older adults and may be used for the management of frailty.

Reduced muscle mass and strength are likely fundamental components of frailty. The purpose of this study was to measure daily muscle activity and quiescence in non-frail, pre-frail, and frail older women using portable electromyography (EMG). Thirty-three community-dwelling older Greek women were categorized as non-frail (n=10, 74±4years), pre-frail (n=11, 75±4years), and frail (n=12, 81±6years) based upon the frailty phenotype. Surface EMG over a 9-hour typical day was recorded from the biceps brachii, triceps brachii, vastus lateralis, and biceps femoris of the dominant side. Burst and gap analysis was used to quantify muscle activity and quiescence. The total duration of the muscles that were active (~2.5h) and quiescent (~4h) did not differ across frailty groups. However, the number of bursts was 28% fewer and the mean burst duration was 26% longer in frail women compared with the non-frail women. In addition, muscle activity was greater in the arm muscles than the thigh muscles across all groups (e.g. ~60% greater burst percentage). Burst number and duration indicate that muscle activity differs across stages of frailty in older women and is greater in the upper compared with lower limbs., (Copyright © 2010 Elsevier Inc. All rights reserved.)

It is unclear during human aging whether healthy older adults (>70 yr old) experience greater, lesser, or the same fatigability compared with younger adults. The reported disparate findings may be related to the task-dependent nature of fatigue and the limited number of studies exploring nonisometric contractile function and aging. The purpose here was to determine the effects of fast shortening contractions on the fatigability of the triceps surae in 10 young (~24 yr old) and 10 old (~78 yr old) men using isometric and dynamic measures. Participants performed 50 maximal velocity-dependent plantar flexions at a constant load of 20% maximal voluntary isometric contraction (MVC). Isometric twitch properties and MVCs were tested at baseline and during and following the fatigue task. Voluntary activation was similar between the old and young (~98%) and was unaltered with fatigue. The old had 26% lower (P < 0.01) isometric MVC torque and 18% slower (P < 0.01) maximal shortening velocity than the young. Hence, peak power was 38% lower in the old (P < 0.01). At task termination, MVC torque was maintained in the old (P = 0.15) but decreased by 21% in the young (P < 0.01). Twitch half-relaxation time was lengthened in the old at task termination by 26% (P < 0.01) but unchanged in the young (P = 0.10). Peak power was reduced by 24% and 17% at task termination in the old and young, respectively (P < 0.01). Despite a better maintenance in isometric MVC torque production, the weaker and slower contracting triceps surae of the old was more fatigable than the young during fast dynamic efforts with an unconstrained velocity.