Functional balance in humans can be characterized as maintaining the center of mass (COM) within the base of support (BOS). When the COM moves outside the BOS, a fall can occur if there is not an ...immediate reaction to modify the BOS. The ability to dynamically control the COM-BOS interaction declines with age, and this increases fall rates in older adults. Falls are multifactorial, and there are some common deficits connected to a change in motor control, as evidenced by greater variability in balance performance. Less variability in motor performance is indicative of a more functional and healthier neuromotor system.There is a gap in the literature with respect to the ability to objectively measure dynamic balance and how it relates to fall-risk. Clinical and perceptual assessments of balance are commonly employed; however, they rely on subjective judgements. Objective assessments have become more available in recent years through sensors in smartphone apps, including the AccWalker app that was developed in our laboratory. Yet, it has been unknown the extent to which these objective measures differ between groups based on age and fall status. This gap was important to address so that smartphone apps can be deployed to the clinical community in order to provide objective, evidence-based assessments of dynamic balance.Treating balance changes had been challenging, despite the designation of falls as a public health concern. Previously, less complete strategies have included strengthening exercises, T’ai Chi, physical therapy and the use of walking assistive devices. A newer strategy with success in the literature is the use of attentional focus cues, particularly external focus instruction. The addition of dynamic balance training with internal (IF) and external focus (EF) cues allows for the examination of the role of attentional focus on fall risk in older adults.This dissertation addressed these gaps in the literature via three specific aims. Manuscript 1 investigated whether older and younger adults were similar in the phone app task for timing of steps in response to the app cue, as well as peak flexion of the right hip. The older adults and younger adults were not different in any variable, but trends were noted with lower variability and greater excursion of thigh flexion for the younger adults and older adults who had not fallen. Manuscript 2 explored the results of the three groups of older adults who were trained with attentional focus cues or were part of the control group. The group that received IF training cues were unchanged for all seven variables of the AccWalker phone app over the twenty-week intervention. In addition, the headshake (HS) condition was unchanged for all seven AccWalker variables over the twenty-week intervention for all three groups. SD stride time, SD peak flexion, and COV peak flexion (variability) increased during training for both eyes open (EO) and eyes closed (EC) conditions, but dropped in the retention phase for EF condition only. Thigh ROM decreased for both control and EF in training but increased for EF only in retention. These results imply a delayed response with EF training, but no effect for IF training.Manuscript 3 investigated the correlation of the variables of standardized tests with the phone variables, and found the Timed Up and Go, Functional Gait Assessment, ABC Scale and Berg Balance Scale were correlated to Thigh ROM and Mean Peak Flexion with all conditions (EO, EC, HS), as well as with step timing variability for FGA and Berg in headshake and eyes closed condition. Grip strength only correlated with the training time frame of the study, but not with balance testing. Grip may be uncorrelated if changes of aging in the upper extremity have disparity to the changes of lower extremities.
This dissertation aimed to quantify the effects of randomized controlled trial (RCT) pediatric lifestyle interventions in treating childhood obesity. An additional aim of the dissertation was to ...examine the efficacy of the BRAVO!, the psychological need-support centered lifestyle intervention, on participants’ body composition and health-related fitness.A systematic review and meta-analysis were conducted to determine the efficacy of RCT pediatric lifestyle interventions in treating obesity among 11- to 17-year-old children. The primary outcome variables were body mass index (BMI), standardized BMI (BMIz), and waist circumference (WC). The results showed that pediatric lifestyle interventions were moderately effective in improving overweight and obese children’s BMI (-1.77 kg/m2, 95% CI -2.65, -.88, p < .001), BMIz (-.30, 95% CI -.44, -.17, p < .001), and WC (-3.72 cm, 95% CI -5.59, -1.85, p < .001). In addition, moderation analyses suggested that lifestyle interventions were the most effective when participants were 13 to 15 years old and at the higher end of the obesity spectrum.Furthermore, to test the efficacy of psychological need-support centered lifestyle intervention BRAVO!, an RCT was conducted with a sample of 40 pediatrician-referred participants (Mage = 13.20 ± 1.54) allocated to two parallel arms: 1) BRAVO! (n = 20) and b) “usual care” (n = 20). The 12-week BRAVO! consisted of 24 exercise sessions (twice/week, 60min/session) and family-based nutrition classes (once/week, 30min/session) and psychological need-support-centered behavior modification. The results showed that BRAVO! was efficacious in generating positive changes in participants’ BMI (F1, 31 = 23.83, p < .001, ηp2 = .45), WC (F1, 31 = 26.58, p < .001, ηp2 = .48), cardiovascular endurance (F1,31 = 8.18, p = .008, ηp2 = .23), upper body (F1, 31 = 28.33, p < .001, ηp2 = .50), and abdominal muscular strength/endurance (F1, 31 = 28.34, p < .001, ηp2 = .45). The changes in cardiovascular endurance vanished over time, but the changes in BMI, WC, upper body muscular and abdominal muscular strength/endurance remained for a longer term. Conclusions: BRAVO! lifestyle program was efficacious in improving at-risk Hispanic children’s body composition and health-related fitness, behavioral, and psychological outcomes in the short and longer term.
Normal aging is often associated with the decline in postural stability and balance in older adults. Consequently, many older adults may face difficulties when using virtual reality (VR) systems, ...where users often experience imbalance effects. Age-related deficits in balance and the imbalance effects caused by VR systems presents a challenging limitation for older adults and general VR usability. However, methods to reduce these effects have not been thoroughly explored. We recruited 20 older adults (>50 years) and 20 young adults (18-24 years) in the present study to investigate and compare the effects of several audio-based feedbacks on postural stability and balance while in an immersive virtual environment (VE). In this study, we used four audio-based feedback conditions: spatial feedback, static feedback, rhythmic feedback, Center of Pressure (CoP)-based feedback, and a no-feedback in VR condition. Participants performed a non-VR standing balance task and a standing reach-to-grasp task. Then, using a head-mounted display (HMD), each participant performed a virtual replication of both the standing balance and standing reach-to-grasp task in VR. We used a force plate to calculate the participant's mean CoP velocity for each audio-based feedback condition during each balance study task. The within-subject results indicated that when spatial feedback was available, older adults exhibited significantly decreased CoP velocity and therefore increased postural stability for both the standing balance task and standing reach-to-grasp task. However, we did not find significant differences in CoP velocity for the static, rhythmic, and CoP-based feedback conditions, nor did we find significant differences in CoP velocities within the young adult participants. In this study, results suggest that spatial feedback techniques can be used in immersive VR environments to improve postural stability and balance in older adult users.
The purpose of this study is to explore how the COVID-19 pandemic has affected coach-athlete relationships for coaches of Ontario, Canada-based adolescent travel sports teams. From March of 2020 ...until May 2021 multiple Ontario youth travel sports organizations canceled/postponed their 2020-2021 seasons because of the worldwide COVID-19 pandemic. Therefore, it is expected that the stoppage of travel adolescent sports in Ontario affected coaches' ability to develop quality coach-athlete relationships. Developing high-quality coach-athlete relationships for coaches and athletes have been positively associated with satisfaction, happiness, and lower levels of burnout within sports. Therefore, qualitatively understanding if and how the COVID-19 pandemic affected coach-athlete relationship development from coaches’ perceptions is valuable information for youth sports organizations so that they can provide positive sporting experiences for coaches and athletes. Six to 15 adolescent travel sport coaches will be recruited from provincial sport organizations (e.g., Dive Ontario) in Ontario. Coaches will be asked to complete a 60–90-minute semi-structured interview via Zoom technology to: explore how the COVID-19 pandemic has impacted their ability to develop their coach-athlete relationships, what strategies they used to cultivate relationships with their athletes during the COVID-19 pandemic and what were the differences and similarities of developing coach-athlete relationships before and during the COVID-19 pandemic from the perspective of the coaches.
This study examined whether accuracy of intraset RIR predictions changes over time. Nine resistance trained men completed three bench press training sessions per week for six weeks, with the last set ...of each session performed until muscular failure. During the set to failure, subjects verbally indicated when they perceived 4 repetitions in reserve (RIR) and 1 RIR during the set. For each RIR prediction, the difference between perceived RIR and actual RIR was calculated as RIRDIFF. We analyzed differences in RIRDIFF using both the raw RIRDIFF (including positive and negative values) and the absolute values of all RIRDIFF using a factorial MANOVA. Covariates included proximity to failure of the RIR prediction, total repetitions performed per set, percentage of one-repetition maximum lifted, the week of training, and the session (1, 2, or 3 within each seek). For the raw RIRDIFF all covariates, except for percentage of 1RM (p > 0.05) were significantly related to the outcome measure at both the predicted 4 and 1 RIR (p < 0.001 to p = 0.04). Specifically, RIRDIFF was significantly higher in weeks 1–4 versus weeks 5–6 (p < 0.001 to p = 0.005). However, the only covariate which significantly impacted the absolute value RIRDIFF at both the predicted 4 (p = 0.033) and 1 RIR (p = 0.022) was total repetitions per set. These results indicate that trained men tend to shift from overpredicting to underpredicting RIR over time and that more repetitions in a set is related to more inaccurate RIR predictions. However, the actual accuracy (i.e., absolute value RIRDIFF) did not significantly change over six weeks of training.
Cancer cachexia (CC) is a devastating wasting syndrome characterized by marked weight loss including skeletal muscle atrophy that affects approximately 80% of cancer patients. Current therapeutic ...treatments including pharmacological and nutritional intervention are insufficient to prevent or reverse it. Prior studies demonstrated lower muscle mass, impaired muscle function, and mitochondrial health in the development of CC. Specifically, mitochondrial fusion protein, Optic atrophy 1 (OPA1) which plays a significant role in skeletal muscle health, is suppressed in the development of CC. Furthermore, most pre-clinical CC studies were mainly focused on males although there are distinct phenotypical differences in skeletal muscle between males and females. Therefore, these studies were set to investigate two independent research questions (Chapter 3 & 4). The purpose of this dissertation project was to investigate skeletal muscle alterations during the development of CC in female tumor-bearing mice (Chapter 3) and determine the efficacy of OPA1 as a therapeutic target for cancer-induced muscle atrophy (Chapter 4). To accomplish this research plan, I completed a series of studies using both cell culture and animal models of CC. For the Chapter 3 experiments, 60 female mice were given either an IP injection of PBS or Lewis Lung Carcinoma (LLC) injection and the tumors were allowed to grow for 1, 2, 3, or 4-wk to assess the time course of cachectic development. We found a dichotomous effect on tumor mass between 3- and 4-wk animals where approximately half of mice between the two groups exhibited low tumor (LT) mass (<1.2 g) while the other half developed higher tumor (HT) mass (>2 g). Furthermore, HT mice revealed greater protein degradation, impaired muscle contractility, and mitochondrial degeneration. These alterations are relatively modest when compared to male data from previous studies. For the Chapter 4 experiments, I utilized both pharmacological (in vitro & in vivo) and genetic overexpression of OPA1 (OPA1 TG) in LLC-conditioned media (LCM) and LLC-induced CC. 72 hours of LCM intervention induced smaller myotubes, which was normalized by BGP-15 treatment and this effect appeared to be driven by suppressed inflammatory cytokine and autophagic-lysosomal pathway (ALP) activity at the mRNA level. 4-wk of LLC implantation was sufficient to induce cachectic phenotype while this effect was normalized in OPA1 overexpression in tumor-bearing mice. In conclusion, my dissertation data suggests both biological sex as an important variable and OPA1 as a novel therapeutic target for cancer-induced muscle wasting.
PURPOSE: The purpose of this study was to compare the effects of 8 weeks performing various resistance training protocols with and without blood flow restriction (BFR) on muscular strength, body ...composition, arterial elasticity, and hemodynamics responses in young males. RESULTS: Significant time*condition interactions occurred in HR period (p <0.05), HDI SBP (p <0.05), HDI MAP (p <0.05), and SV (p <0.05). Trends for time*condition interactions were found in HDI DBP (p=0.054), HDI HR (p=0.051), and HDI SVR (p=0.085). Significant time main effects occurred in all strength measures (p <0.05). Significant condition main effects occurred in Aortic DBP (p <0.05), Brachial DBP (p <0.05), and LAE (p <0.05). Total lean mass significantly increased from baseline the HI condition only (p<0.05).CONCLUSION: Significant improvements in lean mass were seen following the HI and BFR protocols. However, decreases in LAE were found following the HI protocol only. It appears that performing aerobic exercise after resistance training can negatively affect muscle growth. However, only 15 min of moderate-intensity aerobic training can improve hemodynamics in young, healthy males. Improvements in SBP, DBP, SVR, MAP, HR and SV were seen following the HI+AE protocol. KEYWORDS: Blood flow restriction, pulse wave velocity, arterial elasticity
Recently, resisted sprint training has become a widely utilized modality to increase the running speed and acceleration of athletes necessitating fast movements for successful sport performance. ...However, ice hockey is a sport that requires speed and acceleration despite not being running-based. Yet, the impact of a longitudinal resisted sprint training intervention with known resistance on ice skating remains uninvestigated. Ice hockey players engage in both on-ice and overground training. It is presently unknown whether an on-ice resisted sprint training program is superior to an overground resisted sprint training program to increase measures of ice hockey performance. Thus, purposes of this study were: 1) to compare the effects of an on-ice resisted sprint training intervention to an overground resisted sprint training intervention and a control condition (engaging in their usual training routine) for maximal ice skating completion time and other athletic measures associated with ice skating speed and acceleration (broad jump distance, vertical jump performance, isometric force, and overground sprint completion time); 2) to identify changes in ice skating kinematics during maximal ice skating after participation in the respective training intervention; and 3) to examine changes in the magnitude of muscle activation of the knee flexors and extensors during maximal ice skating after participation in the respective training intervention. To achieve these study purposes, 24 competitive youth ice hockey players were equally divided into three groups: 1) on-ice resisted sprint training intervention group (on-ice RST); 2) overground resisted sprint training intervention group (overground RST); and 3) bodyweight training control group (control group). The two RST intervention groups engaged in an 8-week resisted sprint training program, using sled towing methods twice a week on non-consecutive days. Sled towing loads were individualized for maximal power expression with the number of resisted sprints varying depending on the intervention week. Dependent variables were tested before and after the 8-week intervention. A series of repeated ANOVAs with post-hoc comparisons were conducted. All training programs improved certain measures associated with ice skating completion time including broad jump distance F(1,21) = 58.95; p < 0.001; ηp2 = 0.75; large; 21%, vertical jump height F(1,21) = 7.192; p = 0.014; ηp2 = 0.26; large; 7%, 9.14-meter completion time F(1,21) = 7.445; p = 0.013; ηp2 = 0.271; large; 0.06 seconds; 3%, 36-meter completion time F(1,21) = 10.406; p = 0.004; ηp2 = 0.342; large; 0.222 seconds; 4%, and 30-meter top speed completion time F(1,21) = 15.256; p < 0.001; ηp2 = 0.433; large; 0.387 seconds; 12%. Only RST groups substantially altered components of their overground sprint profile components as well as skate profile components Overground: (maximal horizontal force = 15 - 22%); (maximal horizontal power = 13 - 24%); (maximal ratio of force = 3 - 9%); On-ice: (horizontal force = 23 - 29%); (maximal ratio of force = 5 - 7%), knee extensor muscle activity (Overground = 3 - 5%); (On-ice = 10%), and kinematics on-ice step length = 5 - 6%. RST groups displayed superior improvements across ice skating completion time tests, with the on-ice RST displaying a greater magnitude of improvement compared to the overground RST group during 30-meter top speed (6% vs. 1%) and s-cornering agility drill ice skating completion times (10% vs. 4%). Ice hockey coaches should incorporate on-ice RST to improve ice skating completion time across maximal cornering and straight line ice skating tests. When on-ice RST is not feasible, overground RST appears to be an effective alternative to induce comparable changes across most measures.
The developments of sports can be enhanced if adequate attention is given to the indices of sports development. Sports is seen as veritable tool for unity, progress and change, its development in ...Niger State seems to be threatened with the issues of funding, personnel, equipment, facilities as well as inappropriate trainings. Descriptive survey research design was adopted for this study. The population of this study comprised 140 participants with the target population of 140. Since the population of the study was not too large and is within the coverage of the researcher, then there was no sample as all the target population was used as respondents. Self structured questionnaire titled, ‘’Perceived Influence of Management Practices on Sports Development Questionnaire (PIMPSDQ)’’ was used to collect relevant data for the study. The instrument was validated by three lecturers in the department of Human Kinetics and Health Education, Kwara State University, Malete. Test re-test method of reliability of the instrument was established, while Pearson Product Moment Correlation was used to determine the reliability, coefficient and the reliability score of 0.87 was obtained. Mean and Standard Deviation was used to answer five research questions while the five null hypotheses formulated were tested using Linear Regressions statistic at of 0.05 level of significance. The findings revealed that influence of management practices positively contributed to sports development in Niger state sports council. The findings of the study also indicated a positive influence between funding (B = 0.970; t(139) = 24.173, P = 0.000), personnel (B = 0.673; t(139) = 6.874, P = 0.000 < 0.05), equipment (B = 0.451; t(139) = 3.660, P = 0.000< 0.05), facilities (B = 1.302; t(139) = 26.619, P = 0.000< 0.05) and sports development (B = 0.300; t(139) = 2.901, P = 0.004< 0.05). Based on these findings, the study concludes that funding, personnel, equipment, facility and training, significantly influence sports development in Niger State (Sports Council). It was recommended that Niger State Sports Council should employ competent and qualified coaches and trainers personnel who will plan, organise, schedule and execute purposeful sports programme for the athletes. Considering these factors can motivate athletes to participate in sports programme and may be best done by qualified sports personnel and specialists.
Physical activity (PA) enhances quality of life in older adults, yet few older adults participate in regular PA. Exercise prescriptions are valuable to improve PA among older adults, and fitness ...measures are necessary to develop individualized PA programs. A typical fitness measure is the Senior Fitness Test (SFT) conducted in a supervised setting; however, the acceptability of an unsupervised, self-administered SFT is unknown. The purpose of this study was to assess the acceptability of a home-based self-administered SFT versus a home-based supervised SFT using the Theoretical Framework of Acceptability (TFA). Sixty-five older adults performed select SFT measures in their home on two separate occasions, one supervised and one self-administered. Findings indicated both administration methods was acceptable amongst older adults based on the TFA components. Completing a home-based, self-administered SFT appears to be a viable option for physical fitness testing in older adults.
