The Transtheoretical model's processes of change in the heart of a physical activity intervention: A series of n-of-1.

The objectives were a) to test whether a Processes of Change (POC)-personalized Transtheoretical model (TTM)-based intervention could increase physical activity (PA) among inactive adults, and b) to examine whether the intervention increased the level of TTM theoretical constructs. The following hypotheses were formulated: 1) PA levels will be significantly higher during and after the intervention in comparison to baseline measures; 2) the level of targeted POCs will increase during the intervention; 3) non targeted POCs will stay stable, and 4) self-efficacy and decisional balance levels will increase during the intervention. A series of N-of-1 with A (1 to 2-week)-B(10-week)-A'(2-week) design were conducted with 12 inactive adults. Behavioral counselors used behavior change techniques to target TTM constructs and supervise PA. Interventions were individualized based on the 5 POCs with the lowest pre-intervention level. Device-based and subjective PA along with TTM measures were collected weekly online. PA data were analyzed with piecewise linear models. A visual analysis was run to examine the TTM constructs. Device, self-reported and TTM data were available for five, seven and five participants, respectively. A significant self-reported PA increase for six participants was found during the phase B and A2. A significant device-measured PA increase was observed in two participants during the study. A substantial increase of targeted POC from baseline for all participants with available data was observed. This study provides the first evidence of behavioral and psychological effects of a POC-personalized TTM-based intervention in inactive adults.

Prediction of Maximum Lactate Concentration During an All-Out Anaerobic Test in Elite Ice Hockey Players.

The lack of specific on-ice tests to predict maximum lactate concentration limits the ability of coaches to better track and develop their ice hockey players. Thus, this study aimed to develop an equation for indirectly assessing the maximum lactate concentration produced from an all-out on-ice skating effort in elite adolescent ice hockey players. Twenty elite male ice hockey players participated in this study (age = 15.7 ± 1.0 year). The lactate anaerobic skating test (LAST) consisted of skating back and forth on an 18.2 m course at maximal speed with abrupt stops at each end for a total of 6 shuttles (total distance = 218.2 m; average time = 52.0 ± 2.0 s). The oxygen uptake was measured using a portable metabolic analyzer (Cosmed K4b2) and the maximum post-exercise lactate concentration with a Lactate Pro analyzer. The variables used to estimate lactate concentration were time, heart rate, number of skating strides in the last shuffle (6th) and the skating stride index. The average maximum lactate concentration was 14.4 mmol· L-1, which is expected in elite players. The analysis of explained common variance using T-test (r2 = 0.759) and linear regression (r2 = 0.863) demonstrates the validity of the model. Additionally, the root mean square error (RMSE = 0.60 mmol· L-1), the mean absolute error (MAE = 0.45mmol· L-1) and the standard error of estimate (SEE = 0.69 mmol· L-1) values further confirm the accuracy of the model. Thus, using simple and easy-to-measure variables (i.e., time and skating stride), coaches will be able to monitor more effectively their players' progress in an effort to optimize their individual on-ice performance.

Assessment of Training Load, Sleep, Injuries, and Operational Physical Performance During Basic Military Qualification.

INTRODUCTION: Optimizing training load (TL) and sleep is essential to maximize physical performance and prevent musculoskeletal injuries (MSKIs) for Canadian forces recruits during the 10-week basic military qualification (BMQ) course. The purpose of this study was to assess the TL, sleep duration, the occurrence of MSKIs during the BMQ, and the operation fitness performance during the BMQ. MATERIALS AND METHODS: Forty Canadian recruits, eight females and 32 males, (age 24 ± 5 years; height 176.4 ± 10.4 cm), were monitored with an accelerometer (GENEActiv) on their wrist between weeks 1 and 9 to evaluate the TL and sleep duration. During weeks 2 and 10, the recruits completed an operational fitness evaluation. Injury surveillance was performed over 10 weeks. RESULTS: TL intensity was significantly different (P = 0.0001) from week to week. The weekly average total time of moderate and vigorous physical activity was 189.7 ± 48.1 min and 44.7 ± 15.2 min, respectively. The average sleep duration was 5.4 ± 0.4 h per night and decreased to 4.2 h ± 0.4 during field exercises. A significant difference in sleep duration was observed between recruits with and without a MSKI. The recruits accumulated a total of 95 days under medical restrictions with an average of 3.8 consecutive days. The VO2peak estimated from the Fitness for Operational Requirements of Canadian Armed Forces Employment job-based simulation test significantly improved from weeks 2 to 10 (pre, 47.1 ± 6.3; post: 50.2 ± 5.8; P = 0.001). CONCLUSIONS: TL is of high magnitude and varies from week to week. The reported mean sleep duration per week may perhaps negatively impact the occurrence of MSKI. No significant improvement was detected in operational fitness by the end of the BMQ.

Assessment of On-Ice Oxygen Cost of Skating Performance in Elite Youth Ice Hockey Players.

ABSTRACT: Allisse, M, Bui, HT, Desjardins, P, Léger, L, Comtois, AS, and Leone, M. Assessment of on-ice oxygen cost of skating performance in elite youth ice hockey players. J Strength Cond Res 35(12): 3466-3473, 2021-The purpose of this study was to evaluate the robustness of equations to predict the oxygen requirement during different skating circumstances commonly found in ice hockey game situations (skating forward, backward, with and without controlling a puck, during cornering and stops and starts). Twenty-four male elite ice hockey players from 3 categories (pee-wee, bantam, and midget) participated in this study. Anthropometric measurements were taken, and 4 different on-ice high-intensity and short-duration tests were performed. Execution time, heart rate, oxygen uptake, skating strides, and a skating efficiency index were measured for each test. A regression equation was calculated for each of the 4 tests providing an estimation of oxygen cost. Correlation coefficients ranged from 0.91 to 0.93, and SEE was between 4.5 and 8.4%, indicating that the precision of the regression algorithms was excellent. The results also suggest that execution time alone, which is the traditional manner to measure skating performance, is a bad estimator of oxygen uptake requirement for this kind of effort (average common variance <11%). Furthermore, age proved to be a determining factor with younger players showing an overall lower level of skating efficiency compared with older players. In addition, the introduction of a skating index also helps to better determine which factor of performance needs to be improved. Using simple and easy-to-measure variables, coaches will be able to obtain information that will allow them to intervene more precisely on the training parameters that will optimize the individual on-ice performance of their players.

Updating the Skating Multistage Aerobic Test and Correction for V[Combining Dot Above]O2max Prediction Using a New Skating Economy Index in Elite Youth Ice Hockey Players.

Allisse, M, Bui, HT, Léger, L, Comtois, A-S, and Leone, M. Updating the skating multistage aerobic test and correction for V[Combining Dot Above]O2max prediction using a new skating economy index in elite youth ice hockey players. J Strength Cond Res 34(11): 3182-3189, 2020-A number of field tests, including the skating multistage aerobic test (SMAT), have been developed to predict V[Combining Dot Above]O2max in ice hockey players. The SMAT, like most field tests, assumes that participants who reach a given stage have the same oxygen uptake, which is not usually true. Thus, the objectives of this research are to update the V[Combining Dot Above]O2 values during the SMAT using a portable breath-by-breath metabolic analyzer and to propose a simple index of skating economy to improve the prediction of oxygen uptake. Twenty-six elite hockey players (age 15.8 ± 1.3 years) participated in this study. The oxygen uptake was assessed using a portable metabolic analyzer (K4b) during an on-ice maximal shuttle skate test. To develop an index of skating economy called the skating stride index (SSI), the number of skating strides was compiled for each stage of the test. The SMAT enabled the prediction of the V[Combining Dot Above]O2max (ml·kg·min) from the maximal velocity (m·s) and the SSI (skating strides·kg) using the following regression equation: V[Combining Dot Above]O2max = (14.94 × maximal velocity) + (3.68 × SSI) - 24.98 (r = 0.95, SEE = 1.92). This research allowed for the update of the oxygen uptake values of the SMAT and proposed a simple measure of skating efficiency for a more accurate evaluation of V[Combining Dot Above]O2max in elite youth hockey players. By comparing the highest and lowest observed SSI scores in our sample, it was noted that the V[Combining Dot Above]O2 values can vary by up to 5 ml·kg·min. Our results suggest that skating economy should be included in the prediction of V[Combining Dot Above]O2max to improve prediction accuracy.

A Short-Term High-Fat Diet Alters Glutathione Levels and IL-6 Gene Expression in Oxidative Skeletal Muscles of Young Rats.

Obesity and ensuing disorders are increasingly prevalent worldwide. High-fat diets (HFD) and diet-induced obesity have been shown to induce oxidative stress and inflammation while altering metabolic homeostasis in many organs, including the skeletal muscle. We previously observed that 14 days of HFD impairs contractile functions of the soleus (SOL) oxidative skeletal muscle. However, the mechanisms underlying these effects are not clarified. In order to determine the effects of a short-term HFD on skeletal muscle glutathione metabolism, young male Wistar rats (100-125 g) were fed HFD or a regular chow diet (RCD) for 14 days. Reduced (GSH) and disulfide (GSSG) glutathione levels were measured in the SOL. The expression of genes involved in the regulation of glutathione metabolism, oxidative stress, antioxidant defense and inflammation were measured by RNA-Seq. We observed a significant 25% decrease of GSH levels in the SOL muscle. Levels of GSSG and the GSH:GSSG ratio were similar in both groups. Further, we observed a 4.5 fold increase in the expression of pro-inflammatory cytokine interleukin 6 (IL-6) but not of other cytokines or markers of inflammation and oxidative stress. We hereby demonstrate that a short-term HFD significantly lowers SOL muscle GSH levels. This effect could be mediated through the increased expression of IL-6. Further, the skeletal muscle antioxidant defense could be impaired under cellular stress. We surmise that these early alterations could contribute to HFD-induced insulin resistance observed in longer protocols.

Effects of Pursed Lip Breathing on Exercise Capacity and Dyspnea in Patients With Interstitial Lung Disease: A RANDOMIZED, CROSSOVER STUDY.

BACKGROUND: Although mainly described in patients with chronic obstructive pulmonary disease, pursed lip breathing (PLB) could prove useful in patients with interstitial lung disease (ILD) by improving exertional tachypnea and respiratory control. This prospective, randomized, crossover trial aimed at evaluating the impact of PLB on dyspnea and walking distance in ILD patients. METHODS: ILD patients with total lung capacity of <80% predicted were randomized to 6-min walk tests using either PLB or usual breathing. Patients were crossed over for the second 6-min walk tests and served as their own controls. Ventilatory and metabolic variables were recorded using a portable metabolic cart and were compared at 1-min intervals. RESULTS: Thirty-five patients were included (mean forced vital capacity of 64 ± 10% predicted). Use of PLB resulted in lower mean respiratory rates and larger tidal volumes (both P < .001), worsened dyspnea ratings (post-6-min walk test Borg score: 5.2 ± 2.6 vs 4.2 ± 2.3, P < .001), and walking distance (403 ± 102 m vs 429 ± 93 m, P < .001). Twenty-nine patients (83%) described PLB as less comfortable than usual breathing. Both groups had similar total ventilation and oxygen saturation (all P > .05), but PLB resulted in higher mean oxygen uptake (13.9 ± 3.6 vs 12.9 ± 3.2 mL/kg/min, P = .02), even when corrected for walking distance (P < .001). CONCLUSION: In ILD patients, acute exposure to PLB did not improve exertional dyspnea, walking distance, or gas exchange, and was associated with higher metabolic demands than usual breathing. These results cast doubt on the usefulness of this technique in ILD patients and should be taken into account when tailoring pulmonary rehabilitation programs to this population.

Altered Lipid Metabolism Impairs Skeletal Muscle Force in Young Rats Submitted to a Short-Term High-Fat Diet.

Obesity and ensuing disorders are increasingly prevalent in young populations. Prolonged exposure to high-fat diets (HFD) and excessive lipid accumulation were recently suggested to impair skeletal muscle functions in rodents. We aimed to determine the effects of a short-term HFD on skeletal muscle function in young rats. Young male Wistar rats (100-125 g) were fed HFD or a regular chow diet (RCD) for 14 days. Specific force, resistance to fatigue and recovery were tested in extensor digitorum longus (EDL; glycolytic) and soleus (SOL; oxidative) muscles using an ex vivo muscle contractility system. Muscle fiber typing and insulin signaling were analyzed while intramyocellular lipid droplets (LD) were characterized. Expression of key markers of lipid metabolism was also measured. Weight gain was similar for both groups. Specific force was decreased in SOL, but not in EDL of HFD rats. Muscle resistance to fatigue and force recovery were not altered in response to the diets. Similarly, muscle fiber type distribution and insulin signaling were not influenced by HFD. On the other hand, percent area and average size of intramyocellular LDs were significantly increased in the SOL of HFD rats. These effects were consistent with the increased expression of several mediators of lipid metabolism in the SOL muscle. A short-term HFD impairs specific force and alters lipid metabolism in SOL, but not EDL muscles of young rats. This indicates the importance of clarifying the early mechanisms through which lipid metabolism affects skeletal muscle functions in response to obesogenic diets in young populations.

Aquatic Exercise Training Outcomes on Functional Capacity, Quality of Life, and Lower Limb Lymphedema: Pilot Study.

OBJECTIVE: To investigate whether patients with lower limb lymphedema (LLL) can benefit from water immersion exercise training to improve functional capacity, quality of life (QOL), and help control/diminish limb volume. DESIGN: A before-after trial. SETTING: A community University Sports Center. SUBJECTS: Eleven participants were recruited to participate and four declined to pursue the study for personal reasons. A convenient sample of seven female affected by either bilateral or unilateral LLL volunteered for this pilot study. Patients had primary or secondary lymphedema as complications of melanoma or gynecologic cancers. INTERVENTIONS: An aquatic training exercise intervention of moderate to vigorous intensity was conducted for a 6-week period (12 sessions of 45 min). This innovative circuit training program consisted of yoga exercises, aqua-jogging, pedaling on a water bike, and muscular training on an aquastep and a trampoline. OUTCOME MEASURES: The physical characteristics of water could be used to overcome the physical and medical limitations encountered on dry land for patients with LLL to exercise and reach training benefits. Outcome measures were the 6-min walk test (6MWT), handgrip strength test, QOL for limb lymphedema questionnaire (LYMQOL), bioelectrical impedance spectroscopy, and limb circumference. RESULTS: The distance covered in the 6MWT and the handgrip strength were significantly improved. A trend toward an increase in the overall QOL score was noticeable, whereas a significantly improved emotions score was observed with the LYMQOL questionnaire. Limb circumferential volume was significantly lower and impedance was increased, denoting a decrease in lymphatic fluid. CONCLUSIONS: Innovative aquatic exercise training program allows moderate and vigorous intensity activities for patients with LLL, increases functional capacity and QOL. Thus, immersion exercise does not appear to exacerbate LLL and a randomized clinical trial with larger numbers is essential to consolidate the results of this study.

Assessment of the impact of an exercise program on the physical and functional capacity in patients with autosomal recessive spastic ataxia of Charlevoix-Saguenay: An exploratory study.

Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is a neuromuscular disorder caused by the mutation of the SACS gene. Clinical symptoms of this disease include progressive ataxia, spasticity, and peripheral neuropathy. Similar to other neuromuscular disorders, these patients are prone to physical deconditioning which may lead to a loss of functional capacity. This paper aims to evaluate the impact of a training program on the physical fitness and the functional capacity of ARSACS patients. Twelve patients (age: 28.1 ± 8.2 years) participated in this study. They followed an eight-week training program including physical activities, strength-power and aerobic training. Compared to the initial evaluation, measures of physical fitness and functional capacity were significantly improved (p ≤ 0.05) for 11 of the 12 tests. Positive gains were also observed for fall frequency and for upper-limb incoordination. This paper supports the importance of a training program for ARSACS patients in order to improve their quality of life. Through these types of interventions, it may be possible to slow down the progression of the disease and help maintain functional capacity.

Altered Feeding Behaviors and Adiposity Precede Observable Weight Gain in Young Rats Submitted to a Short-Term High-Fat Diet.

Information regarding the early effects of obesogenic diets on feeding patterns and behaviors is limited. To improve knowledge regarding the etiology of obesity, young male Wistar rats were submitted to high-fat (HFD) or regular chow diets (RCDs) for 14 days. Various metabolic parameters were continuously measured using metabolic chambers. Total weight gain was similar between groups, but heavier visceral fat depots and reduced weight of livers were found in HFD rats. Total calorie intake was increased while individual feeding bouts were shorter and of higher calorie intake in response to HFD. Ambulatory activity and sleep duration were decreased in HFD rats during passive and active phase, respectively. Acylated and unacylated ghrelin levels were unaltered by the increased calorie intake and the early changes in body composition. This indicates that at this early stage, the orexigenic signal did not adapt to the high-calorie content of HFD. We hereby demonstrate that, although total weight gain is not affected, a short-term obesogenic diet alters body composition, feeding patterns, satiation, ambulatory activity profiles, and behaviours in a young rat model. Moreover, this effect precedes changes in weight gain, obesity, and ensuing metabolic disorders.

Pilot project: Physiologic responses to a high-intensity active video game with COPD patients-Tools for home rehabilitation.

INTRODUCTION: Chronic obstructive pulmonary disease (COPD) is a respiratory condition that causes a significant deterioration of the quality of life. However, exercise can improve the quality of life for COPD patients and it is for this reason previous study observed the effects of active video games to increase exercise. Using motion capture devices with short bursts of exercise never been tried with COPD patients. OBJECTIVES: The objective was to observe the feasibility of using this device safely and easily with COPD patients. METHODS: A total of 14 participants (8 men, 69 ± 6 years, 6 women, 74 ± 6 years), with a moderate to severe COPD diagnosis performed exercise games (Shape-Up, Ubisoft, Mtl) adapted under supervision. Gaming sessions of 10-15 min duration were composed of four games of about 1.5 min separated by rest. RESULTS: Average and peak minute ventilation, and METs peak were, respectively: Stunt Run game (lifting knees on spot) 25.3 ± 6.8, 33.5 ± 8.2 L/min and 4.2 ± 1.5 METs; Arctic Punch game (punching targets): 23.1 ± 5.6, 31.8 ± 9.8 L/min and 3.7 ± 1.2 METs; To the Core game (core twist), 22.2 ± 7.3, 29.2 ± 9.9 L/min and 3.3 ± 1.1 METs; and Squat me to the Moon game (sitting to standing), 27.8 ± 6.7, 36.8 ± 11.1 L/min and 4.4 ± 1.1 METs. CONCLUSION: Knowing the pleasure reported by the participants, the safety, and the ability to use it with assistance, it seems that the games could be a good tool in order for COPD patients to exercise at home. However, further investigation needs to be completed in order to observe the benefits in comparison to a traditional training program.

Acute effects of water immersion on heart rate variability in participants with heart disease.

BACKGROUND: Water immersion and aquatic exercise can be an important therapeutic tool in patients suffering from heart disease (HD). However, the effects of water immersion on heart rate variability (HRV) in HD participants remain unknown. METHODS: Twenty-eight volunteers in sinus rhythm within the same age range took part in this study: 18 HD and ten healthy controls (HC). Heart rhythm was collected with a heart rate monitor (sampling rate 1000 Hz) for periods of 10 min at rest in the supine position on land, standing on land (STL) and standing in water (STW) to the xiphoid process. RESULTS: Heart disease participants had the same response as HC participants to the three experimental conditions (no significant between-group differences in all HRV variables). STW (immersion) caused in both groups to increase HRV when compared to supine and STL. CONCLUSION: Heart disease participants demonstrate similar beneficial adaptations as HC participants to the effects of immersion, reinforcing the concept that immersion can be a valuable aquatic cardiac rehabilitation tool to acutely increase HRV. Approaches that improve HRV in both healthy and cardiac patients may have a positive impact on the reduction of morbidity and mortality.

Acute cardiorespiratory responses in participants with heart disease during cycling at different immersion levels.

Physical activity is often avoided or practised at a low-intensity level because of the limited ability of patients with heart disease (HD) to provide sustained effort. Immersible training has been suggested as a possible alternative as hydrostatic pressure can modify some hemodynamic parameters in healthy patients and potentially increase the exercise capacity in patients with HD. The purpose of this study was to examine the acute cardiorespiratory adaptations at different levels of immersion using an immersible ergometer (IE) in patients with HD. Twenty-one patients and 13 healthy controls (HC) participated in this study. Several cardiorespiratory parameters were assessed at two levels of immersion (hips and xiphoid) for five different pedalling rates (40, 50, 60, 70 and peak rpm). At submaximal intensity, HD and HC participants did not differ significantly for most variables. However, for nearly and/or maximal workload, HD participants showed significantly lower values for VO2 and higher values for VE /VO2 and VE /VCO2 for both immersion levels. The increase in immersion level from hips to xiphoid resulted in a significant decrease in VO2 in both HC and HD groups at the same exercise intensity. In addition, the increase in the effects of size values based on the exercise workload indicates that group differences are accentuated with the highest pedalling rates. Our data suggest that participants with HD may benefit from the hydrostatic effect during IE cycling by allowing them to alleviate their submaximal efforts and increasing their maximal cardiorespiratory capacity during hip immersion.

Morphological, Physiological and Skating Performance Profiles of Male Age-Group Elite Ice Hockey Players.

The purpose of this study was to describe the evolution of morphological, physiological and skating performance profiles of elite age-group ice hockey players based on repeated measures spread over one season. In addition, the results of fitness tests and training programs performed in off-ice conditions and their relationship with skating performance were analyzed. Eighteen high level age-group ice hockey players (13.1 ± 0.6 years) were assessed off and on-ice at the beginning and at the end of the hockey season. A third evaluation was also conducted at the beginning of the following hockey season. The players were taller, heavier, and showed bone breadths and muscle girths above the reference population of the same age. Muscular variables improved significantly during and between the two hockey seasons (p < 0.05). However, maximal aerobic power improved only during the off-season. All skating performance tests exhibited significant enhancements during the hockey season, but not during the off-season where some degradation was observed. Finally, weak observed variances (generally <20% of the explained variance) between physiological variables measured off-ice and on-ice skating performance tests indicated important gaps, both in the choice of the off-ice assessment tools as well as in training methods conventionally used. The reflection on the best way to assess and train hockey players certainly deserves to be continued.

Immersible ergocycle prescription as a function of relative exercise intensity.

PURPOSE: The purpose of this study was to establish the relationship between various expressions of relative exercise intensity percentage of maximal oxygen uptake (%VO2max), percentage of maximal heart rate (%HRmax), %VO2 reserve (%VO2R), and %HR reserve (%HRR)) in order to obtain the more appropriate method for exercise intensity prescription when using an immersible ergocycle (IE) and to propose a prediction equation to estimate oxygen consumption (VO2) based on IE pedaling rate (rpm) for an individualized exercise training prescription. METHODS: Thirty-three healthy participants performed incremental exercise tests on IE and dryland ergocycle (DE) at equal external power output (Pext). Exercise on IE began at 40 rpm and was increased by 10 rpm until exhaustion. Exercise on DE began with an initial load of 25 W and increased by 25 W/min until exhaustion. VO2 was measured with a portable gas analyzer (COSMED K4b2) during both incremental tests. On IE and DE, %VO2R, %HRmax, and %HRR at equal Pext did not differ (p > 0.05). RESULTS: The %HRR vs. %VO2R regression for both IE and DE did not differ from the identity line %VO2R IE = 0.99 × HRR IE (%) + 0.01 (r 2 = 0.91, SEE = 11%); %VO2R DE = 0.94 × HRR DE (%) + 0.01 (r 2 = 0.94, SEE = 8%). Similar mean values for %HRmax, %VO2R, and %HRR at equal Pext were observed on IE and DE. Predicted VO2 obtained according to rpm on IE is represented by: VO2 (L/min) = 0.000542 × rpm2 - 0.026 × rpm + 0.739 (r = 0.91, SEE = 0.319 L/min). CONCLUSION: The %HRR-%VO2R relationship appears to be the most accurate for exercise training prescription on IE. This study offers new tools to better prescribe, control, and individualize exercise intensity on IE.

Comparison and analysis of three different methods to evaluate vertical jump height.

The purpose of this study was to compare three methods to assess vertical jump height, to determine their limitations and to propose solutions to mitigate their effects. The chosen methods were the contact mat, the optical system and the Sargent jump. The testing environment was designed such that all three systems simultaneously measured the vertical jump height. A total of 41 kinesiology students (18 women, 23 men, mean age 23·2 ± 4·5 years) participated in this study. Data show that the contact mat and the optical system essentially provide similar results (P = 0·912) and that the correlation coefficient between the two systems was 0·972 (r(2)  = 0·944). However, it was found that the Sargent jump has a tendency to overestimate the height, providing a measurement that is significantly different from the other two methods as the jumps are higher than 30·64 cm (P = 0·044). Through the design of the experiment, several sources of errors were identified and mathematically modelled. These sources include optical sensor placement, flat-footed landing and hip/knee bend. Whenever possible, the errors were quantified and solutions were proposed.

Assessment of gross motor skills and phenotype profile in children 9-11 years of age in survivors of acute lymphoblastic leukemia.

BACKGROUND: The purpose of this study was to evaluate the usefulness of a new gross motor skill test battery in acute lymphoblastic leukemia (ALL) children who have been off therapy for at least 1 year and to assess its discriminatory power (discriminant analysis) from healthy children. PROCEDURE: Twenty children (10 males and 10 females) 9-11 years of age (median age = 10.6 years) were assessed by the UQAC-UQAM test battery and then compared to recent provincial norms. This pilot study was also an opportunity to validate this test battery as a reliable tool for clinical or research purposes in the area of chronic or disabling diseases in children. Eleven motor skill variables grouped into five factors have been measured (speed, agility, balance, coordination, and reaction time). RESULTS: Scores from 10 of the 11 motor skill tests showed significant differences when compared to the control group (P ≤ 0.05). Nearly 50% of patients obtained an average score below the 15th percentile. Furthermore, stepwise discriminant analysis allowed classifying successfully 88.4% of children in the correct group (ALL or Control). The normal development of GMS among children affected by ALL appears to have been compromised. The UQAC-UQAM test battery seems to be sensitive enough to quantify with precision the extent of the motor impairment in these children. CONCLUSION: The UQAC-UQAM test battery appears to be a useful tool to evaluate the extent to which ALL survivors are affected. Early motor intervention should be considered for those patients even during the treatment periods.