Anthony A. Vandervoort’s research while affiliated with Western University and other places

Flexibility is the range of motion (ROM) available in a joint or group of joints and can be increased via a flexibility or stretching program. Despite the well-established and long-standing inclusion of stretching programs for fitness routines, there are currently scientific discussions regarding the utility of stretching exercises, which are regularly recommended for overall health and conducted as a part of preexercise protocols to reduce injury and increase performance in athletic-type activities. The implication of this “debate” for the older adult population warrants further discussion, as age-related declines in joint-specific ROM are observed. For the majority of the aging population, ROM status may not be related to fitness activity performance but rather to performance of the activities of daily living. For this reason, the promotion of flexibility in the older adult population is substantial. This chapter reviews the age-related declines of various body parts and how they may relate to function and quality of life as we age. Existing recommendations are based on limited evidence precluding the offering of guidance as to a flexibility intervention related to maintaining or improving functional ROM for older adults. While ROM decreases with age, older adults do maintain the ability to regain ROM. This chapter summarizes the role of physical activity levels and exercise interventions in the maintenance and training of ROM. The pressing need for high-quality, purposive study of flexibility is warranted in order to establish the magnitude of impact on function.

Background: Although the benefits of exercise are well-known, guidelines often target the general public or individuals living with single pathologies. Currently, there is no systematic exercise prescription approach for individuals with multiple chronic diseases. Objective: To determine overlapping physiological and subjective markers for use by clinicians to define safe exercise for individuals with multiple chronic diseases. Methods: Eight databases were used to complete a comprehensive systematic review. Thirty-nine articles met the inclusion criteria for chronic obstructive pulmonary disease (COPD), coronary artery disease (CAD) and type two diabetes mellitus (T2DM). Four reviewers extracted all qualitative and quantitative data. Results: Findings show that: 1) aerobic and resistance training done 2-3 times per week is beneficial for individuals with chronic diseases, and 2) overlapping ranges of physiological and subjective markers can be used to determine safe exercise prescription. Exercise for the chronic diseases searched is safe with overlapping markers including: systolic and diastolic blood pressure, Borg scale, VO2Max, and heart rate. Each disease state did have unique markers that must be monitored to ensure safety during exercise. Specifically, with COPD SpO2 should be kept above 90%, for CAD exercise heart rate should be kept 10 bpm below causing angina symptoms, and for diabetes blood glucose should be kept between 100-300 mg/dl. Conclusion: This review shows initial evidence for a multi-system approach to exercise prescription, which suggests screening key physiological markers from various body systems in order to safely prescribe exercise to individuals with multiple chronic diseases.

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 historydependence 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±3.7 years) and 9 old (76.1±5.4 years) men were performed on a HUMAC NORM dynamometer as a reference, and then again following an active shortening of 40o joint excursion (40oPF-0oPF) at angular velocities of 15o/s and 120o/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 15o/s and 120o/s of shortening. Old produced 37% and 21% less work for 15o/s and 120o/s than young, respectively. Furthermore, old experienced 60% and 70% greater shortening-induced TD than young for 15o/s and 120o/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 (R2=0.32) and young (R2=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.

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.

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.

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.