Response of Knee Joint Biomechanics to Landing Under Internal and External Focus of Attention in Female Volleyball Players

The aim of this study was to examine the effect of attentional focus instructions on the biomechanical variables associated with the risk of anterior cruciate ligament injury of the knee joint during a drop landing task using a time series analysis. Ten female volleyball players (age: 20.4 ± 0.8 years, height: 169.7 ± 7.1 cm, mass: 57.6 ± 3.1 kg, experience: 6.3 ± 0.8 years) performed landings from a 50 cm height under three different attentional focus conditions: (1) external focus (focus on landing as soft as possible), (2) internal focus (focus on bending your knees when you land), and (3) control (no-focus instruction). Statistical parameter mapping in the sagittal plane during the crucial first 30% of landing time showed a significant effect of attentional focus instructions. Despite the similarity in landing performance across foci instructions, adopting an external focus instruction promoted reduced vertical ground reaction force and lower sagittal flexion moment during the first 30% of execution time compared to internal focus, suggesting reduced knee loading. Therefore, adopting an external focus of attention was suggested to reduce most biomechanical risk variables in the sagittal plane associated with anterior cruciate ligament injuries, compared to internal focus and control condition. No significant differences were found in the frontal and horizontal planes between the conditions during this crucial interval.

The Roles of Perceived Physical Education Competence, Enjoyment, and Persistence on Middle School Students' Physical Activity Engagement

We examined gender and grade differences in the relationship between students' perceived competence, their enjoyment of physical education (PE), and their PA persistence on the frequency of their physical activity (PA). We also used structural equation modeling to assess the direct, indirect, and total effects of perceived competence and PE enjoyment on PA frequency through the mediator of PA persistence. Participants were 223 middle school students (115 boys, 108 girls) in grades 7 and 8. We found that, regardless of grade level, girls had lower perceived competence and PE enjoyment than boys. Both perceived competence and PE enjoyment had significant direct and positive connections to persistence, but they had no significant indirect effects on PA frequency through the mediator of persistence. These findings highlight the need for physical educators to be aware of gender differences in perceived competence and PE enjoyment, and the important roles these factors have in enhancing students' PA participation.

External focus of attention enhances arm velocities during volleyball spike in young female players

The aim of this study was to investigate the effect of different volleyball-specific attentional focus instructions on arm velocities of a volleyball spike in young female volleyball players using the Statistical Parametric Mapping method. Twelve young female volleyball players (13.6 ± 0.6 years old, 1.8 ± 0.8 years of experience in volleyball training) were asked to perform a volleyball spike in a standing position in three different attentional focus conditions including internal focus (IF, i.e., pull back your elbow prior to transfer momentum), external focus, (EF, i.e., imagine cracking a whip to transfer momentum), and control (CON, i.e., no-focus instruction). A Qualisys 3D motion capture-system was used to track reflective markers attached to the arm, forearm, and hand. Consequently, four phases of the volleyball spike including wind-up, cocking, acceleration, and follow-through were analyzed. A one-way repeated-measure ANOVA using one-dimensional statistical parametric mapping (SPM1d) showed that players achieved greater velocities in the hand (p < 0.01), forearm (p < 0.01), and arm (p < 0.01) using the EF instructions from the start of the wind-up phase to the acceleration phase. Post-hoc (SPM1d-t-tests-paired) analyses indicated significantly greater arm, forearm, and hand velocities during the EF condition, compared to CON (p < 0.01, p < 0.01, and p < 0.01 respectively) and IF (p < 0.01, p < 0.01, and p < 0.01 respectively) conditions. These findings suggest that EF instructions had an immediate impact on increasing volleyball spike velocity from the start of the wind-up phase to the acceleration phase prior to ball contact.

Examining the Delivery of a Tailored Chinese Mind-Body Exercise to Low-Income Community-Dwelling Older Latino Individuals for Healthy Aging: Feasibility and Acceptability Study

Background

Older Latino individuals are disproportionally affected by various chronic conditions including impairments in physical and cognitive functions, which are essential for healthy aging and independent living.

Objective

This study aimed to evaluate the feasibility and acceptability of FITxOlder, a 12-week mind-body exercise program, in community-dwelling low-income, predominantly older Latino individuals, and assess its preliminary effects on health parameters relevant to healthy aging and independent living.

Methods

This 12-week, single-arm, stage 1B feasibility study had a pre- and poststudy design. A total of 13 older adults (mean age 76.4, SD 7.9 years; 11/13, 85% Latino) of a congregate meal program in a senior center were enrolled. FITxOlder was a tailored Chinese mind-body exercise program using Five Animal Frolics led by a bilingual community health worker (CHW) participating twice a week at the senior center and facilitated by mobile health technology for practice at home, with incrementally increasing goals moving from once a week to at least 3 times a week. The feasibility and acceptability of the study were examined using both quantitative and qualitative data. Healthy aging–related outcomes (eg, physical and cognitive function) were assessed using paired 2-tailed t tests. Qualitative interview data were analyzed using thematic analysis.

Results

The attendance rate for the 24 exercise sessions was high (22.7/24, 95%), ranging from 93% (1.8/2) to 97% (1.9/2) over the 12 weeks. Participants were compliant with the incremental weekly exercise goals, with 69.2% (9/13) and 75.0% (9/12) meeting the home and program goals in the last 4 weeks, respectively. Approximately 83% (10/12) to 92% (11/12) of the participants provided favorable feedback on survey questions regarding the study and program implementation, such as program content and support, delivery by the CHW, enjoyment and appeal of the Five Animal Frolics, study burden and incentives, and safety concerns. The qualitative interview data revealed that FITxOlder was well accepted; participants reported enjoyment and health benefits and the desire to continue to practice and share it with others. The 5-time sit-to-stand test (mean change at posttest assessment=−1.62; P<.001; Cohen d=0.97) and 12-Item Short Form Health Survey physical component scores (mean change at post intervention=5.71; P=.01; Cohen d=0.88) exhibited changes with large effect sizes from baseline to 12 weeks; the other parameters showed small or medium effect sizes.

Conclusions

The research findings indicated that the CHW-led and mobile health–facilitated Chinese qigong exercise program is feasible and acceptable among low-income Latino older adults. The trending health benefits of the 12-week FITxOlder program suggest it is promising to promote physical activity engagement in underserved older populations to improve health outcomes for healthy aging and independent living. Future research with larger samples and longer interventions is warranted to assess the health benefits and suitability of FITxOlder.

Adapting Chinese Qigong Mind-Body Exercise for Healthy Aging in Older Community-Dwelling Low-income Latino Adults: Pilot Feasibility Study

BACKGROUND

Research translating the evidence for the benefit of mind-body exercise in older Latinos with limited access to community-based healthy aging programs is sparse.

OBJECTIVE

This study aimed to evaluate the feasibility of Function Improvement Exercises for Older Sedentary Community-Dwelling Latino Residents (FITxOlder), a Community Health Worker (CHW)-led, mobile technology-facilitated Chinese Qigong mind-body exercise program for healthy aging and to explore its impact on physical and cognitive function and quality of life (QoL) in older community-dwelling low-income Latino adults.

METHODS

This study was designed as a Stage 1 feasibility study to develop and pilot-test FITxOlder. In Phase 1 (Stage 1A), a working group of seniors, CHWs, and senior center staff guided the adaptation of Chinese Qigong into a healthy aging program. In Phase 2 (Stage 1B), 49 older Latino adults participated in a 3-arm controlled study to test the feasibility and preliminary effect of CHW-led FITxOlder on physical and cognitive function and QoL measures over 16 weeks.

RESULTS

Although the COVID-19 pandemic disrupted the implementation of the study protocol, we found favorable results regarding participant recruitment, retention, and fidelity of implementation. Notable findings included an 89.3% participant retention, 79.4% of the participants completed at least 70% of the weekly exercise goal, and no report of adverse events. The effects on intervention outcome measures were modest.

CONCLUSIONS

FITxOlder is feasible for promoting healthy aging in older Latino adults; future research needs to compare its feasibility with other low-impact exercise programs for healthy aging using a randomized controlled trial.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04284137; https://clinicaltrials.gov/ct2/show/NCT04284137.

Higher levels of physical activity buffered the negative effect of pain severity on physical frailty in older Latinx adults

This cross-sectional study examined whether and to what extent physical activity (PA) mediated the effect of chronic pain on physical frailty in a sample of predominantly older Latinx adults. Study participants were 118 community-dwelling older adults in southwest United States. Physical frailty was measured by a summary score of physical function tests. Pain severity and pain interference were measured by the Brief Pain Inventory. PA levels were defined as meeting the PA recommendation by 7-day accelerometry. Pain outcomes and PA were associated with physical frailty, respectively. Hierarchical regression analysis revealed that PA mediated the relationship between pain severity and physical frailty. However, no mediation effect of PA was found in the relationship between pain interference and physical frailty scores. Higher levels of PA buffered the negative effect of pain severity on physical frailty. Future studies should pay attention to PA promotion to prevent the negative consequences of frailty in older minority adults.

Children's motor imagery modality dominance modulates the role of attentional focus in motor skill learning

We investigated whether children's motor imagery dominance modulated the relationship between attentional focus and motor learning of a tossing task. One hundred and thirty-eight boys (age: M = 10.13, SD = 0.65) completed the Movement Imagery Questionnaire - Children (MIQ-C) to determine imagery modality dominance (kinesthetic, internal-visual, external-visual) and were randomly assigned to either an internal (n = 71) or external (n = 67) attentional focus group. Participants completed 60 trials of a tossing task with their non-dominant hand on day 1. Participants in the internal focus group were asked "to focus on the throwing arm", whereas participants in the external focus group were instructed "to focus on the ball." A retention test was conducted 24 h later to assess motor learning. Overall, the results from a nested, multiple linear regression analysis indicated the degree to which internal or external focus influences children's throwing accuracy is dependent upon their motor imagery modality dominance. Specifically, higher levels of external-visual imagery dominance resulted in greater motor learning for children adopting an external focus. In contrast, higher values of kinesthetic imagery dominance resulted in reduced motor learning for children who adopted an external focus. Despite the need for future research, we recommend motor imagery modality dominance assessments be considered when investigating the influence of attentional focus on motor learning, particularly when the target population is children.

External relative to internal attentional focus enhances motor performance and learning in visually impaired individuals

Background: Research has demonstrated the advantages of an external relative to internal focus of attention for enhancing motor performance and learning across diverse tasks, contexts and populations. However, research has yet to examine whether this finding holds true for individuals who have a major visual impairment in discrete and locomotion-based continuous motor tasks.Methods: In experiment 1, twenty-four visually impaired participants were asked to kick a soccer ball with their dominant foot to a target 7 meters away. Participants performed 10 trials within an internal focus (concentration on inside of the foot), external focus (concentration on the ball), and control (no focus instructions) conditions, in a counterbalanced order. In experiment 2, thirty-nine visually impaired adults were asked to ride a rehabilitation Pedalo for a distance of 7 meters. Participants were randomly assigned to either an internal focus (focus on the feet), external focus (focus on the platform), or control (no focus instructions) group. Retention and transfer tests were conducted on day 2.Results: An external focus resulted in more accurate kicks and faster pedalo movement times compared to an internal focus.Conclusions: These findings indicate that visual information does not mediate external focus benefits for motor performance and learning.Implications for RehabilitationPractitioners should use instructions that encourage visually impaired individuals who are going through rehabilitation to adopt an appropriate focus of attention for enhancing motor performance and learning of discrete or locomotion-based motor skills.Instructions that foster an external focus, relative to an internal focus, enhances performance of both discrete and continuous motor skills in individuals with visual impairment.

The Influence of Attentional Focus Instructions and Vision on Jump Height Performance

PURPOSE

Studies have suggested that the use of visual information may underlie the benefit associated with an external focus of attention. Recent studies exploring this connection have primarily relied on motor tasks that involve manipulation of an object (object projection). The present study examined whether vision influences the effect of attentional focus on the performance of body movements through space (body projection).

METHOD

Participants (N = 24, M_age = 25.0 ± 3.3 years) performed a maximum vertical jump in a room with a 4-m ceiling under full-vision and no-vision conditions. Additionally, participants performed 3 trials under each of 3 attentional conditions, presented in a counterbalanced order: external focus (ExF; "concentrate on the ceiling and try to touch it"), internal focus (InF; "concentrate on your fingers and try to bring them up as high as possible"), and control (Con; no-focus instruction).

RESULTS

Results indicated that regardless of visual condition, a statistically significant difference was observed such that participants in the ExF condition (30.93 ± 8.37 cm) jumped significantly higher than participants in both the InF (30.09 ± 8.66 cm, p = .004, d = 0.68) and Con (30.23 ± 8.73 cm, p = .002, d = 0.57) conditions. Furthermore, jump height was overall significantly higher in the full-vision condition compared with the no-vision condition (p = .004, d = 0.47). Importantly, there was no interaction between ExF and vision.

CONCLUSION

The present findings demonstrate the benefit of an ExF on a body projection task and further provide evidence of the independence of ExF and visual information.

Action Effects and Task Knowledge: The Influence of Anticipatory Priming on the Identification of Task-Related Stimuli in Experts

The purpose of the present study was to examine the extent to which anticipation of an action’s perceptual effect primes identification of task-related stimuli. Specifically, skilled (n = 16) and novice (n = 24) tennis players performed a choice-reaction time (CRT) test in which they identified whether the presented stimulus was a picture of a baseball bat or tennis racket. Following their response, auditory feedback associated with either baseball or tennis was presented. The CRT test was performed in blocks in which participants predictably received the baseball sound or tennis sound irrespective of which stimulus picture was displayed. Results indicated that skilled tennis players responded quicker to tennis stimuli when the response was predictably followed by the tennis auditory effect compared to the baseball auditory effect. These findings imply that, within an individual’s area of expertise, domain-relevant knowledge is primed by anticipation of an action’s perceptual effect, thus allowing the cognitive system to more quickly identify environmental information. This finding provides a more complete picture of the influence that anticipation can have on the cognitive-motor system. No differences existed for novices.

Effects of Physical Practice and Imagery Practice on Bilateral Transfer in Learning a Sequential Tapping Task

Recent research on bilateral transfer suggests that imagery training can facilitate the transfer of motor skill from a trained limb to that of an untrained limb above and beyond that of physical practice. To further explore this effect, the present study examined the influence of practice duration and task difficulty on the extent to which imagery training and physical training influences bilateral transfer of a sequential key pressing task. In experiment 1, participants trained on the key pressing task using their non-dominant arm under one of three conditions (physical practice, imagery practice, and no practice). In a subsequent bilateral transfer test, participants performed the sequential task using their untrained dominant arm in either an original order or mirror-ordered sequence. In experiment 2, the same procedures were followed as in experiment 1 except that participants trained with their dominant arm and performed the bilateral transfer task with their non-dominant arm. Results indicated that with extended practice beyond what has been employed in previous studies, physical practice is more effective at facilitating bilateral transfer compared to training with imagery. Interestingly, significant bilateral transfer was only observed for transfer from the non-dominant to the dominant arm with no differences observed between performing the task in an original or mirror ordered sequence. Overall, these findings suggest that imagery training may benefit bilateral transfer primarily at the initial stages of learning, but with extended training, physical practice leads to larger influences on transfer.

Perceptual-Cognitive Changes During Motor Learning: The Influence of Mental and Physical Practice on Mental Representation, Gaze Behavior, and Performance of a Complex Action

Despite the wealth of research on differences between experts and novices with respect to their perceptual-cognitive background (e.g., mental representations, gaze behavior), little is known about the change of these perceptual-cognitive components over the course of motor learning. In the present study, changes in one's mental representation, quiet eye behavior, and outcome performance were examined over the course of skill acquisition as it related to physical and mental practice. Novices (N = 45) were assigned to one of three conditions: physical practice, combined physical plus mental practice, and no practice. Participants in the practice groups trained on a golf putting task over the course of 3 days, either by repeatedly executing the putt, or by both executing and imaging the putt. Findings revealed improvements in putting performance across both practice conditions. Regarding the perceptual-cognitive changes, participants practicing mentally and physically revealed longer quiet eye durations as well as more elaborate representation structures in comparison to the control group, while this was not the case for participants who underwent physical practice only. Thus, in the present study, combined mental and physical practice led to both formation of mental representations in long-term memory and longer quiet eye durations. Interestingly, the length of the quiet eye directly related to the degree of elaborateness of the underlying mental representation, supporting the notion that the quiet eye reflects cognitive processing. This study is the first to show that the quiet eye becomes longer in novices practicing a motor action. Moreover, the findings of the present study suggest that perceptual and cognitive adaptations co-occur over the course of motor learning.

Visual and skill effects on soccer passing performance, kinematics, and outcome estimations

The role of visual information and action representations in executing a motor task was examined from a mental representations approach. High-skill (n = 20) and low-skill (n = 20) soccer players performed a passing task to two targets at distances of 9.14 and 18.29 m, under three visual conditions: normal, occluded, and distorted vision (i.e., +4.0 corrective lenses, a visual acuity of approximately 6/75) without knowledge of results. Following each pass, participants estimated the relative horizontal distance from the target as the ball crossed the target plane. Kinematic data during each pass were also recorded for the shorter distance. Results revealed that performance on the motor task decreased as a function of visual information and task complexity (i.e., distance from target) regardless of skill level. High-skill players performed significantly better than low-skill players on both the actual passing and estimation tasks, at each target distance and visual condition. In addition, kinematic data indicated that high-skill participants were more consistent and had different kinematic movement patterns than low-skill participants. Findings contribute to the understanding of the underlying mechanisms required for successful performance in a self-paced, discrete and closed motor task.

Whole-body posture planning in anticipation of a manual prehension task: prospective and retrospective effects

This study examined the extent to which the anticipation of a manual action task influences whole-body postural planning and orientation. Our participants walked up to a drawer, opened the drawer, then grasped and moved an object in the drawer to another location in the same drawer. The starting placement of the object within the drawer and the final placement of the object in the drawer were varied across trials in either a blocked design (i.e., in trials where the same start and end location were repeated consecutively) or in a mixed fashion. Of primary interest was the posture adopted at the moment of grasping the drawer handle before pulling it out prior to the object manipulation task. Of secondary interest was whether there were sequential effects such that postures adopted in preceding trials influenced postures in subsequent trials. The results indicated that the spatial properties of the forthcoming object manipulation influenced both the postures adopted by the participants and the degree to which the drawer was opened, suggesting a prospective effect. In addition, the adopted postures were more consistent in blocked trials than in mixed trials, suggesting an additional retrospective effect. Overall, our findings suggest that motor planning occurs at the level of the whole body, and reflects both prospective and retrospective influences.

From action representation to action execution: exploring the links between cognitive and biomechanical levels of motor control

Along with superior performance, research indicates that expertise is associated with a number of mediating cognitive adaptations. To this extent, extensive practice is associated with the development of general and task-specific mental representations, which play an important role in the organization and control of action. Recently, new experimental methods have been developed, which allow for investigating the organization and structure of these representations, along with the functional structure of the movement kinematics. In the current article, we present a new approach for examining the overlap between skill representations and motor output. In doing so, we first present an architecture model, which addresses links between biomechanical and cognitive levels of motor control. Next, we review the state of the art in assessing memory structures underlying complex action. Following we present a new spatio-temporal decomposition method for illuminating the functional structure of movement kinematics, and finally, we apply these methods to investigate the overlap between the structure of motor representations in memory and their corresponding kinematic structures. Our aim is to understand the extent to which the output at a kinematic level is governed by representations at a cognitive level of motor control.

Examination of visual information as a mediator of external focus benefits

Attunement to visual information has been suggested to mediate the performance advantage associated with adopting an external focus of attention (e.g., Al-Abood, Bennett, Moreno Hernandez, Ashford, & Davids, 2002; Magill, 1998). We tested this hypothesis by examining the extent to which online visual information underpins the external focus advantage. The study examined skilled golfers on a putting task under one of three attentional focus conditions: control (no instructions), irrelevant (tone counting), and external (movement effect focus), with either full or occluded vision. In addition to task performance, the effect of attentional focus and vision on between-trial movement variability was examined. We found a significant advantage for an external focus of attention in the absence of vision. The results of the movement variability analysis further indicated that external focus was not mediated by the online use of vision. We discuss these findings in the context of traditional cognitive perspectives to external focus effects.