The role of ankle and knee muscle characteristics in spatiotemporal gait parameters at different walking speeds: A cross-sectional study.

BACKGROUND: Understanding the intricate interplay between ankle and knee muscle characteristics and their impact on gait parameters is crucial for enhancing our comprehension of human locomotion, particularly in the context of varying walking speeds among healthy young adults. RESEARCH QUESTION: The study aimed to identify the relative importance of ankle and knee flexor and extensor muscle characteristics (e.g., strength estimated by peak torque [PT] and rate of torque development [RTD]) in the spatiotemporal gait parameters and variability in self-selected (SSWS) and fast walking speeds (FWS) in healthy young adults. METHODS: One hundred and thirty-nine adults (75 men - 54% and 64 women - 46%; 29.04 ± 9.55 years) were assessed about their muscle characteristics (PT and RTD by an isokinetic dynamometer) and spatiotemporal gait parameters at different walking speeds (SSWS and FWS by an instrumented walkway). RESULTS: Data analysis indicated a weak relationship between the PT and RTD of the ankle and knee and spatiotemporal gait parameters and variability in both walking conditions (SSWS: R2 0.14-0.05; FWS: R2 0.40-0.05). The strength of the knee muscles was more relevant when walking at a self-selected speed, while the strength of the ankle muscles played a more prominent role when walking at a fast pace. SIGNIFICANCE: The findings underscore the critical role of ankle muscles (plantar and dorsiflexors) at fast walking speeds. Therefore, targeted interventions for strength and optimization of these muscles are paramount.

An Experimental Approach to Induce Trips in Lower-Limb Amputees.

Reestablishing balance after a trip is challenging for lower-limb amputees and often results in a fall. The effectiveness of reestablishing balance following a trip depends on factors such as amputation level (transtibial or transfemoral) or which limb is tripped (prosthetic or sound/lead or trailing). Understanding the recovery responses can help identify strategies to avoid a trip becoming a fall and what trip-response functionality could be designed into a prosthesis. This study presents an experimental approach for inducing unexpected trips in individuals with amputation. Tripping was manually triggered by activating an electromagnetic device to raisea polypropylene wire to obstruct (bring to a near halt) theswinging limb during its mid-swing phase. A safety harness attached to a ceiling rail ensured participants did not hit the ground if they failed to reestablish balance following the trip (i.e., it prevented a fall from occurring). One transtibial amputee completed repeated walking trials in which a trip was induced around 1 out of 15 times to avoid it being anticipated. 3D kinematics were determined via two smartphones (60Hz) using the OpenCap software, highlighting that the experimental approach induced meaningful tripping/recovery responses dependent on which limb was tripped (prosthetic or sound). The presented methodology avoids using a rigid obstacle, potentially reducing the risk of injuries, and is inexpensive and easy to set up. Importantly it permits a trip to be unexpectedly introduced during the mid-swing phase of the gait and hence provides an approach for identifying real-world trip recovery responses. When tripping the sound limb, participants could 'disentangle' from the trip-wire (post-trip) by plantarflexing the ankle, but such action was not possible when tripping the prosthetic limb.

Control of center of mass during gait of stroke patients: Statistical parametric mapping analysis.

BACKGROUND: The control of the center of mass is essential for a stable and efficient gait. Post-stroke patients present several impairments, which may compromise the control of the center of mass during gait in the sagittal and frontal planes. This study aimed to identify changes in the vertical and mediolateral behavior of the center of mass during the single stance phase of post-stroke patients using the statistical parametric mapping analysis. It also aimed to identify alterations in the center of mass trajectories regarding the motor recovery stages. METHODS: Seventeen stroke patients and 11 neurologically intact individuals were analyzed. The statistical parametric mapping approach was used to identify changes in the center of mass trajectories between stroke and healthy groups. The trajectories of the center of mass of post-stroke individuals were compared according to their motor recovery status. FINDINGS: A near-flat vertical trajectory of the center of mass was indenfitifed in the stroke group compared to their healthy counterparts, especially on the paretic side. The center of mass trajectories in both directions (vertical and mediolateral) presented substantial alteration at the end of the single stance phase in the stroke group. The trajectory of the center of mass of the stroke group was symmetrical in the mediolateral direction between the sides. The trajectories of the center of mass presented similar pattern irrespective of the motor recovery status. INTERPRETATION: The statistical parametric mapping approach showed to be suitable for determining gait changes in post-stroke individuals, irrespective of their motor recovery stage.

Time profile of kinematic synergies of stroke gait.

BACKGROUND: In stroke subjects, the motor skills differ between sides and among subjects with different levels of motor recovery, impacting inter-joint coordination. How these factors can affect the kinematic synergies over time during gait has not been investigated yet. This work aimed to determine the time profile of kinematic synergies of stroke patients throughout the single support phase of gait. METHODS: Kinematic data from 17 stroke and 11 healthy individuals was recorded using a Vicon System. The Uncontrolled Manifold approach was employed to determine the distribution of components of variability and the synergy index. To analyze the time profile of kinematic synergies, we applied the statistical parametric mapping method. Comparisons were made within the stroke group (paretic and non-paretic limbs) and between groups (stroke and healthy). The stroke group was also subdivided into subgroups with worse and better motor recovery. FINDINGS: There are significant differences in synergy index at the end of the single support phase between stroke and healthy subjects; paretic and non-paretic limbs; and paretic limb according to the motor recovery. Comparisons of mean values showed significantly larger values of synergy index for the paretic limb compared to the non-paretic and healthy. INTERPRETATION: Despite the sensory-motor deficits and the atypical kinematic behavior, stroke patients can produce joint covariations to control the center of mass trajectory in the forward progression plane, but the modulation of the synergy is impaired, reflecting altered adjustments, especially in the paretic limb of subjects with worse levels of motor recovery.

Complete recovery of quadriceps muscle peripheral fatigue after running in Olympic, but not Sprint, triathlon.

This study compared central and peripheral fatigue development between the Sprint and Olympic distance triathlon. Fifteen male triathletes performed Sprint and Olympic triathlon simulations in a randomized and counterbalanced order. Central and peripheral fatigue was evaluated from changes in voluntary activation level (VAL) and twitch responses of quadriceps muscle (Qtw,pot), respectively. Qtw,pot reduced from baseline to post-swimming similarly between triathlon simulations (Sprint,-17±11%; Olympic, -13±9%). In post-cycling, Qtw,pot further declined to a similar extent between triathlon distances (Sprint, -31±15%; Olympic, -28±11%). In post-running, Qtw,pot was fully recovered in the Olympic triathlon (-4±10%), whereas there was only a partial recovery of Qtw,pot in the Sprint triathlon (-20±11%). VAL was not reduced in post-swimming, but reduction was similar between triathlon distances in post-cycling (Sprint, -10±9%; Olympic, -8±8%) and post-running (Sprint, -15±14%; Olympic, -16±8%). In the Sprint triathlon, the swimming speed (1.07±0.13m.s-1) was above (p <.001) critical speed (1.01±0.14m.s-1), the cycling power (179.7±27.2W) was below the respiratory compensation point (216.3±27.8W, p <.001) and running speed (13.7±1.05km.h-1) similar to the respiratory compensation point (13.2±0.70km.h-1, p =.124). In the Olympic triathlon, swimming speed (1.03±0.13m.s-1) was similar to critical speed (p =.392), and cycling power (165.3±27.3W) and running speed (12.6±1.05km.h-1) were below the respiratory compensation point (p ≤.007). In conclusion, peripheral fatigue progressed until post-cycling regardless of triathlon distances. However, peripheral fatigue was fully recovered after running in Olympic but not in Sprint triathlon. The central fatigue started in post-cycling and progressed until post-running regardless of triathlon distances.HighlightsThe quadriceps muscle peripheral fatigue progresses similarly in Sprint and Olympic triathlons until post-cycling.The quadriceps muscle peripheral fatigue is completely recovered after running in the Olympic triathlon, whereas it is partially recovered in the Sprint triathlon.The central fatigue starts in post-cycling and progresses similarly until post-running in Sprint and Olympic triathlons, regardless of triathlon distances.

Are the spatiotemporal gait parameters at different walking speeds capable of predicting variations in cognitive status by the mini-mental state examination?

BACKGROUND: Several studies have reported the association between cognition and gait; however, most are limited to investigating gait in just one speed, usually the self-selected one, and commonly, only the general score of cognitive tests is used. AIMS: Investigate the relationship between the spatiotemporal gait parameters at different speeds (self-selected and fast walking speeds) and cognitive status in older adults. METHODS: Cross-sectional study. Two hundred and ninety-five older adults (70.9 ± 7.2 years; 82.3% women) were evaluated according to cognitive status (Mini-Mental State Examination, MMSE) and spatiotemporal gait parameters. RESULTS: Data analysis indicates that the spatiotemporal gait parameters (stride length, step time, and single support time) were able to predict cognitive status, assessed by the MMSE general score and its subdomain (temporal and spatial orientation) at both walking speeds. CONCLUSIONS: The spatiotemporal gait parameters were associated with cognitive status, assessed by the MMSE (general score and temporal and spatial orientation), regardless of the walking conditions. The model's variance was significant and with a large effect size. Stride length and step time were identified as the variables with the best explanatory factors. Therefore, it is concluded that greater cognitive performance is associated with longer stride lengths and faster step times.

Smartphones dependency risk analysis using machine-learning predictive models.

Recent technological advances have changed how people interact, run businesses, learn, and use their free time. The advantages and facilities provided by electronic devices have played a major role. On the other hand, extensive use of such technology also has adverse effects on several aspects of human life (e.g., the development of societal sedentary lifestyles and new addictions). Smartphone dependency is new addiction that primarily affects the young population. The consequences may negatively impact mental and physical health (e.g., lack of attention or local pain). Health professionals rely on self-reported subjective information to assess the dependency level, requiring specialists' opinions to diagnose such a dependency. This study proposes a data-driven prediction model for smartphone dependency based on machine learning techniques using an analytical retrospective case-control approach. Different classification methods were applied, including classical and modern machine learning models. Students from a private university in Cali-Colombia (n = 1228) were tested for (i) smartphone dependency, (ii) musculoskeletal symptoms, and (iii) the Risk Factors Questionnaire. Random forest, logistic regression, and support vector machine-based classifiers exhibited the highest prediction accuracy, 76-77%, for smartphone dependency, estimated through the stratified-k-fold cross-validation technique. Results showed that self-reported information provides insight into predicting smartphone dependency correctly. Such an approach opens doors for future research aiming to include objective measures to increase accuracy and help to reduce the negative consequences of this new addiction form.

Clinical-Functional Vulnerability, Functional Capacity, and Falls in Octogenarians with Different Physical Activity Levels-A Cross-Sectional Study.

AIM: To compare differences between frailty, functional capacity, and fall prevalence among community-dwelling oldest-old adults regarding their physical activity levels. METHODS: Two hundred and thirty-nine octogenarians (80+ years) were allocated according to their physical activity as insufficiently active (<150 min week-1; n = 98; 84.4 ± 3.7 years), active (150 to 300 min week-1, n = 81, 83.9 ± 3.1 years), and very active (>300 min week-1, n = 60; 83.8 ± 3.4 years). Frailty (CFVI-20 questionnaire), functional capacity (Five Times Sit-to-Stand Test, Timed Up and Go, Balance, and handgrip strength), fall history, and physical activity were assessed. RESULTS: The insufficiently active group was the frailest and presented the worst functional performance compared to the other groups. The fall prevalence was higher in the insufficiently active (60.9%) compared to the active (26.4%) and very active (12.7%) groups. CONCLUSIONS: The group of insufficiently active octogenarians showed the greatest frailty, worst functional capacity, and higher fall prevalence than the active and very active groups. The engagement in physical activity of at least 300 min week-1 is essential to reverse or minimize the deleterious effects of aging on frailty, functional capacity, and falls in octogenarians.

Multifactorial Assessment of Older Adults Able and Unable to Recover Balance During a Laboratory-induced Trip.

BACKGROUND: Older adults are prone to falls, and identifying fallers and non-fallers from a set of fall-related variables is essential while establishing effective preventive programs. AIMS: This study aimed to analyze if a set of parameters (i.e., strength, functional status, dynamic balance, gait, and obesity-related anthropometric measures) differ between older adults able and unable to recover from an induced trip. OBJECTIVE: To analyze predictors among older adults able and unable to identify fallers and nonfallers. METHODS: Thirty healthy old adults were tripped once during the mid-swing phase of the gait. The trip outcome was used as a criterion to assign participants to a recovery (REC; n=21; 71.2±5.7 years; 70.9±12.8 kg; 1.60±0.09 m) or a non-recovery group (NREC; n=9; 69.4±6.8 years; 85.7±11.8 kg; 1.59±0.08 m). The spatiotemporal gait parameters, functional mobility, dynamic balance, and isokinetic muscular function were measured. RESULTS: The NREC presented larger BMI (33.6±2.7 vs. 27.5±3.4 kg.m-2; p<0.05); greater time for the initiation phase on the voluntary step execution test (197.0±27.9 vs. 171.7±31.3s; p<0.05); lower plantarflexor (0.41±0.15 vs. 0.59±0.18 N.m; p<0.05), dorsiflexor (0.18±0.05 vs. 0.24±0.07 N.m; p<0.05), knee extensor (1.03±0.28 vs. 1.33±0.24 N.m; p<0.05) and knee flexor peak torques (0.50±0.15 vs. 0.64±0.13 N.m; p<0.05); and greater time up and go (8.0±0.8 vs. 7.4±0.7 s). CONCLUSION: The results showed that it is possible to identify fall risk components based on several fall-related parameters using a laboratory-induced trip as the outcome variable.

A cross-sectional analysis of the muscle strength, spinal shrinkage, and recovery during a working day of military police officers.

OBJECTIVE: Military personnel has a large prevalence of back pain, especially those involved in patrolling routines, as they wear heavy protective equipment. Patrolling includes long periods of sustaining the protective equipment in a sitting or in a motor vehicle (motorcycle or car). Thus, understanding spinal loading of military police officers after patrolling by car (CAR; n = 14), motorcycle (MOT; n = 14), and administrative (ADM; n = 14) routines is relevant to establish preventive strategies. METHODS: The torque of the trunk and working and anthropometric characteristics were assessed to explain spinal loading using stature variation measures. Precise stature measures were performed before and after a 6 h journey (LOSS) and 20 min after a resting posture (RECOV). The trunk extensor (PTE BM-1 ) and flexor (PTF BM-1 ) muscles' isometric peak torque were measured before the working journey. RESULTS: The LOSS was similar between CAR and MOT (4.8 and 5.8 mm, respectively) after 6 h of patrolling. The ADM presented the lowest LOSS (2.8 mm; P < .05). No changes in RECOV between groups were observed (P > .05). Vibration may explain the greater spinal loading involved in patrolling in comparison to the ADM. A GLM analysis revealed that BMI was the only explanatory factor for stature loss. No independent variables explained RECOV. The ability of the trunk muscles to produce force did not influence LOSS or RECOV. CONCLUSIONS: Military police officers involved in patrolling may require greater post-work periods and strategies designed to reduce the weight of the protective apparatus to dissipate spinal loading. The external load used in patrolling is a relevant spinal loading factor.

Exergames Training Effects on Gait During Single and Dual Tasks in Sexagenarian Women.

Objective: This study was designed to analyze the effects of an exergames training program on gait parameters while holding a cellphone conversation at self-selected walking speed (SSWS) and fast walking speed (FWS). Materials and Methods: Twenty-one older women (66.3 ± 4.0 years) practiced exergames for 12 weeks and were assessed for spatiotemporal gait parameters at SSWS and FWS under single task and dual task. The strength of the lower limbs was measured by an isokinetic dynamometer (Byodex System 3). The cognitive function was assessed with the Montreal Cognitive Assessment (MoCA). The tests were assessed 4 weeks before the start of the exergames training (baseline, T0), immediately before (pretraining, T1), and at the end of 12 weeks of the exergame training (post-training, T2), except for the MoCA test that was assessed at T0 and T2. Results: The spatiotemporal gait parameters at SSWS and FWS showed extensive changes when a cellphone conversation was sustained (e.g., 6.5% and 5.8% reduction in walking speed, respectively). Exergames training was not effective in minimizing these changes or improving muscle strength after 12 weeks (<3.0%). Minor cognitive improvements (0.5 points) were observed in response to training. Conclusion: Holding a cellphone conversation while walking changed several gait parameters, irrespective of the walking speed. The spatiotemporal gait parameters and lower limb muscle strength in sexagenarian women remained unchanged after the exergames training program.

Kinematic Variables of Disabled Swimmers and Their Correlation With the International Paralympic Committee Classification.

This study described the kinematic variables of disabled swimmers' performance and correlated them with their functional classification. Twenty-one impaired swimmers (S5-S10) performed 50-m maximum front-crawl swimming while being recorded by four underwater cameras. Swimming velocity, stroke rate, stroke length, intracycle velocity variation, stroke dimensions, hand velocity, and coordination index were analyzed. Kendall rank was used to correlate stroke parameters and functional classification with p < .05. Swimming velocity, stroke length, and submerged phase were positively correlated with the para swimmers functional classification (.61, .50, and .41; p < .05, respectively), while stroke rate, velocity hand for each phase, coordination index, and intracyclic velocity variation were not (τ between -.11 and .45; p > .05). Thus, some objective kinematic variables of the impaired swimmers help to support current classification. Improving hand velocity seems to be a crucial point to be improved among disabled swimmers.

Immediate Effects of Acupuncture on Force and Delayed Onset of Muscle Soreness.

Background: The ability to produce force is critical to several daily activities. Strategies to reduce delayed onsent muscle soreness (DOMS) and restore force-generating properties that occur in response to training and impair physical performance have been proposed. Acupuncture has been proposed to accelerate recovery and optimize muscle functioning. It was to determine the effects of acupuncture on DOMS and on the muscle force production capacity. Methods: Thirty physically active volunteers (26.3 ± 3.1 years old, 1.70 ± 0.08 m, 66.5 ± 12.6 kg) were allocated in a control (CG; n = 10), placebo (PG; n = 10), and acupuncture (AG; n = 10) groups. The groups were subjected to an exercise protocol to induce DOMS and were assessed for muscle force, threshold, and rate of perceived pain and activation of the biceps brachialis muscle before (PRE) and 20 minutes after (POST) a single acupuncture session using a mixed model analysis. Results: The threshold and rate of perceived pain were reduced in the AG (P < 0.05) but remained unchanged in the other groups (P > 0.05). Muscle activation also showed larger changes in the AG in comparison with the other groups (P < 0.05). No changes in the ability to produce force were found after acupuncture in any groups (P > 0.05). Conclusions: Acupuncture may reduce discomfort and improve muscle activation but was not effective to promote force improvement and/or restore the force-generating properties. It may be speculated that muscle disruption may have played a role and did not allow participants to restore their muscular performance. Rebec Number; RBR-8bh5k7 (www.ensaiosclinicos.gov.br/rg/RBR-8bh5k7); Clinical Trial Registry (UTN No.: U1111-1234-9553).

Gait Parameters of Older Adults according to Their Fall History and Functional Capacity While Walking at Different Speeds.

INTRODUCTION: It is believed that functional capacity and fall history are factors capable of influencing the gait parameters of older adults. Thus, the objective of this study was to verify whether gait parameters of community-dwelling older adults differ according to their functional capacity and fall history when walking at self-selected walking speed (SSWS) and fast walking speed (FWS) using principal component analysis (PCA). METHODS: Two hundred ninety-five participants (82.3% women and 17.7% men) were allocated in four groups according to their fall history and functional capacity: non-fallers with higher functional capacity (NFHFC, n = 94; 69.3 ± 5.5 years), non-fallers with lower functional capacity (NFLFC, n = 114; 72.0 ± 8.1 years), fallers with higher functional capacity (FHFC, n = 29; 70.0 ± 6.0 years), and fallers with lower functional capacity (FLFC, n = 58; 72.5 ± 8.2 years). Fall history, anthropometric data, functional capacity by short physical performance battery and mobility by Timed Up and Go (TUG), and spatiotemporal gait parameters were evaluated. RESULTS: Data analysis indicated that FLFC presented the lowest scores, especially in the Five Times Sit-to-Stand Test and TUG. The PCA showed that the first principal component (PC1) explained the most substantial amount of the data variability in both walking speeds (SSWS and FWS), predominantly including temporal parameters. PC2 composed by spatial outcomes (stride and step length and walking speed) showed the highest effect size. PC1 and PC2 were able to differentiate functional status, regardless of fall history. CONCLUSIONS: Functional capacity showed great importance when analyzing gait parameters at different walking speeds (SSWS and FWS), regardless of fall history. Older adults with high functional capacity demonstrate better performance during gait. Besides, spatiotemporal parameters are the main factors explaining gait variability, both in SSWS and FWS.

Can Age Influence Functional Tests Differently to Predict Falls in Nursing Home and Community-Dwelling Older Adults?

Aim: The aim of this cross-sectional study was to determine which functional tests are able to predict falls in nursing home residents (NHR) and community-dwelling (CDW) older adults grouped by age. Methods: Two hundred and fifty-two older adults were assessed in the following tests, Mini-Mental State Examination, anthropometric characteristics, fall history and functional tests. The participants were assigned to one of the following groups: Young Older Adults (YOA; 60-69 years, n = 102; 27.5% NHR), Old Older Adults (OOA; 70-79 years; n = 100; 23.5% NHR) and Very Older Adults (VOA, ≥80 years; n = 50; 52% NHR). Results: The five times sit-to-stand showed 1.41 odds to experience a fall in the NHR of the VOA. In the CDW, the handgrip strength score decreased the odds to fall occurrence (0.92 odds) in the YOA, while the low score in timed up and go test of the OOA showed 1.21 odds to experience a fall. Conclusions: Therefore, the five times sit-to-stand test can predict falls in NHR of VOA groups, while handgrip strength and timed up and go tests can predict falls in CDW of YOA and OOA groups, respectively.

Aquatic exercise improves functional capacity, perceptual aspects, and quality of life in older adults with musculoskeletal disorders and risk of falling: A randomized controlled trial.

BACKGROUND: This study aimed to determine the effects of an aquatic training program on functional capacity, perceptual aspects, and quality of life (QoL) performed by older adults with musculoskeletal disorders (MSDs) and moderate/high risk of falls. METHODS: This randomized controlled trial included 120 older adults assigned to aquatic exercises (AG; n = 60; 70.62 ± 6.04 years) and a control group (CG; n = 60; 71.86 ± 6.95 years). The risk of falls, perceptual aspects (fall risk awareness and pain), functional capacity (lower and upper body strength, lower and upper body flexibility, functional mobility, and balance) and QoL were assessed at baseline and after the experimental protocol. The AG performed 16 weeks of aquatic exercises (twice per week, 45 min.session-1) with lower and upper body strength, stretching, and balance exercises. Exercise intensity was controlled using the rate of perceived exertion (12-16 on the Borg scale [6-20 points]) and heart rate (progressing from 40% to 60% of the heart-rate reserve). RESULTS: The training program improved the lower (mean difference [95% CI]: 2.7 [2.0 to 3.3]) and upper body strength (3.5 [2.6 to 4.5]), lower (4.6 [3.4 to 5.8]) and upper body flexibility (6.5 [4.3 to 8.6]), functional mobility (-2.5 [-2.9 to -1.9]), and balance (11.2 [10.6 to 11.9]); reduced pain perception (-3.2 [-3.7 to -2.8]); increased the fall risk awareness (9.5 [8.8 to 10.1]) and QoL perception (5.6 to 22.6 [4.6 to 25.1]). CONCLUSIONS: The water-based program may be used as a preventive approach for the older adults with MSDs and at risk of falling to improve physical and usual perceptual aspects (QoL and pain) and fall risk awareness.

Is Handgrip Strength a Useful Measure to Evaluate Lower Limb Strength and Functional Performance in Older Women?

AIM: This study aimed to determine the association of handgrip strength with isometric and isokinetic strength (hip, knee and ankle extensor/flexor muscles), and functional capacity in older women. METHODS: The handgrip strength and lower limb strength of 199 older women (60-86 years) were measured using JAMAR and BIODEX dynamometers, respectively. Time Up and Go, Five-times-sit-to-stand and 6m-walk functional tests were evaluated. Pearson correlations were used to determine the relationship between variables. Regression analysis was applied to identify if HS was able to predict TUG performance. The effect of age was analyzed by splitting the participants in a group of older women (OLD; from 60 to 70 years old) and very old women (from 71 to 86 years old). RESULTS: The HS and isometric/isokinetic strength correlations were negligible/low and, in most cases, were non-significant. The correlation between handgrip strength and functional tests also ranged predominantly from negligible (r=0.0 to 0.3) to low (r=0.3 to 0.5), irrespective of the group age. The handgrip strength was not able to explain the variance of the TUG performance. CONCLUSION: Generalizing handgrip strength as a practical and straightforward measure to determine lower limbs and overall strength, and functional capacity in older women must be viewed with caution. Handgrip strength and standard strength measures of the lower limbs and functional tests present a negligible/low correlation.

Kinematic Parameters After Repeated Swimming Efforts in Higher and Lower Proficiency Swimmers and Para-Swimmers.

Purpose: The aim of this study was to determine changes in swimming parameters, stroke coordination, and symmetry after repeated high-intensity swimming efforts in swimmers of different performance levels and para-swimmers. Method: Forty swimmers (20 able-bodied, allocated to higher and lower performance groups-G1 and G2, respectively-and 20 impaired swimmers-S5 to S10) were recorded by four underwater cameras while performing repeated 50 m maximum front-crawl swimming with a ten-second interval for each time endured by the swimmer. A cycle stroke was digitized using SIMI Reality Motion Systems in the first and last trials to analyze the kinematic parameters. The comparison among groups and conditions was performed by Mixed ANOVA Models with p < .05. Results: For all groups, swimming velocity, stroke rate, and stroke index showed reduction over time, while stroke length and intracyclic velocity variation did not show significant changes. Conclusions: Training to maintain stroke rate is necessary to support performance since it is the main cause of velocity decrease. Stroke dimensions and individual underwater phases were not sufficient to distinguish groups or conditions. Hand velocity decreased probably due to a decline in energy capacity, propulsive force and passive drag caused by the fatigue process.

The Effects of Different Exergame Intensity Training on Walking Speed in Older Women.

Objective: It is not known if the intensity in which exergames are performed can change gait parameters at different walking speeds. This study was designed to determine if a training program based on exergame exercises performed at different intensities (moderate vs. vigorous) influences walking speed and gait parameters in older adult women. Methods: After applying the inclusion criteria, 20 participants (69.5 ± 5.4 years) were randomized into two groups: moderate (11-13 perceived exertion) and vigorous (14-16 perceived exertion). Walking speed and gait parameters at self-selected walking speed (SSWS) and maximal walking speed (MWS) were evaluated before and after 3 months of exergame training. The walking speed and gait parameters were measured with an instrumented walkway. The walking speed reserve (WSR) was calculated as a difference and ratio. Results: There was pre-to-post effect of walking speed at self-selected walking pace (pre = 112.1 ± 16.4 cm.s-1; post = 124.8 ± 16.4 cm.s-1), in WSR calculated as ratio (pre = 1.35 ± 0.08; post = 1.28 ± 0.09), in a number of gait parameters at SSWS (step length, stride length, stride velocity, step time, stride time, swing time, stance time, single support, double support, gait cycle time, and cadence) and at MWS (step time, stride time, swing time, single support, double support, gait cycle time, and cadence). Conclusion: Irrespective of the exercise intensity, exergame training improved walking speed only at a self-selected walking pace and some gait parameters at self-selected and MWS in older women.

Sport and Exercise Psychology Studies in Brazil: Performance or Health?

The low professional insertion of psychologists in Brazilian sports teams, as well as the Sport Psychology course being seldom offered in undergraduate Psychology courses, may reflect in the current scenario of scientific research in Brazil. It is still not clear what Graduate Programs (GPs) have adopted directions regarding the development of studies in Sport and Exercise Psychology (SEP) research fields since an assessment or mapping of scientific knowledge production in this area has not yet been performed involving Exercise and Sport Science and Psychology GPs. This study aimed at investigating institutional research and their themes in SEP from these graduate programs. Studies were selected and retrieved from a national database (Sucupira Platform), that contains all registered researches from all Exercise and Sport Science (n = 31) and Psychology (n = 84) GPs in the country. Data were analyzed through R software using text mining techniques, latent semantic analysis and K-means clustering. Results revealed that research involving SEP is predominantly being developed at Exercise and Sport Science GPs (n = 171; p < 0.01) in comparison to psychology GPs (n = 39), mostly located in the south and southeast regions of Brazil. This research has focused on the effects of physical exercise and quality of life, while Psychology GPs have analyzed sport as associated with health and education, as a way to promote social support and to study sports' psychological aspects. It was concluded that Exercise and Sport Science GPs had the most significant contribution to SEP. Investigations were focused on the interface of exercise with quality of life, health and education, with gaps existing in programs advancing in the studies on sports and performance.