The Effects of Either a Mirror, Internal or External Focus Instructions on Single and Multi-Joint Tasks

Attentional Focus Effects on Lower-Limb Muscular Strength in Athletes: A Systematic Review

ABSTRACT

Pompa, D, Carson, HJ, Beato, M, di Fronso, S, and Bertollo, M. Attentional focus effects on lower-limb muscular strength in athletes: A systematic review. J Strength Cond Res 38(2): 419-434, 2024-Evidence links an athlete's focus of attention to enhancing strength performance. However, additional research is needed to investigate the applicability of studies beyond the tasks and population currently examined. Therefore, we aimed to systematically review studies concerning attentional focus effects on strength characteristics on lower-limb tasks in athletes. Scopus, Web of Science, and EBSCO databases were searched using PRISMA PERSIST guidelines and keywords related to the focus of attention, force production processes, and athletes. Subjects were categorized: world class (tier 5); elite (tier 4); highly trained (tier 3); trained/developmental (tier 2); nonathletes (tiers 1-0); and mixed (different levels). Fifteen of 296 studies met the inclusion criteria. Included studies investigated the focus of attention effects on performance ( n = 6), between skill levels ( n = 2), and for learning ( n = 5), with respect to subject preference ( n = 1); one study did not state the aim. Studies achieved an average risk of bias score of "excellent"; however, findings suffered in the assessment of certainty. Only 2 studies reported an advantage for one type of attentional focus (external focus) across conditions ( g = 0.13-0.42) with tier 2 and mixed tier athletes. Research does not address the needs of elite athletes, and there is limited evidence on each type of strength characteristics and muscle action. There is also a need to incorporate methodological steps to promote task-relevant instructions. Research should focus on contextualized information within professional practice to offer stronger translational implications for athletes and coaches.

The effects of attentional focus on speech motor control in adults who stutter with and without social evaluative threat

PURPOSE

We sought to investigate the effects of cued attentional shifts on speechmotor control in adults who stutter (AWS) and adults who do not stutter (ANS) when speaking under low and high social stress conditions.

METHOD

Thirteen AWS' and 10 ANS' lip aperture (LA) and posterior tongue (PT) movements were assessed under a Cued-Internal and Cued-External attentional focus condition with and without social stress induction (i.e. speaking to an audience). Skin conductance levels were used to measure a stress response. Speech motor control was assessed by measuring movement duration and variability of movement for LA and PT using the spatial temporal index (STI).

RESULTS

A significant Group x Condition interaction was found for LA STI. Post-hoc comparisons indicated AWS' LA STI significantly decreased under Cued External Focus conditions during both low and high social stress. No significant Group x Condition interaction was found for PT STI. AWS showed significantly slower tongue movements (PT) across all low and high social stress conditions; however, there was no significant Group x Condition interaction for PT or LA.

DISCUSSION

Findings yield preliminary insights into the role of attentional focus on speech motor control when speaking during high social stress. Theoretical and clinical implications are discussed.

A Pilot Study on Attentional Focus in Prescribing Physical Exercise in Outpatients with Obesity

This pilot study compared the effects of two attentional focus strategies on fitness parameters and body composition in outpatients with obesity. This was a randomized, controlled study that enrolled 94 obese individuals and allocated them into an internal focus group (IF) or an external focus group (EF) while performing six weeks of a home-based training program. The home-based exercise program was the same for both groups except for the instructions that shifted the attention to an external or an internal condition. At the beginning and after the intervention period, participants were assessed for functional performance using the Functional Movement Screen (FMS), body balance using the Modified Balance Error Scoring System (M-BESS) and muscular strength with the Handgrip Strength Test (HST) and the Five-Repetition Sit-To-Stand (FRSTS) test. Concerning body composition and anthropometric parameters, the body mass index (BMI) and fat mass percentage (FM%) were calculated. Significant improvements, main interactions and effects of time and groups were highlighted in the EF group as compared to the IF group in FMS (35% vs. 21%), M-BESS (42% vs. 18%), HST (13% vs. 7%) and FRSTS (23% vs. 12%) measures, while FM% (5%) and BMI (6% vs. 5%) showed a similar improvement overtime (p < 0.001). In conclusion, our findings provide initial evidence that a 6-week training program performed following external focus instruction is able to promote significant enhancements in movement efficiency, balance and muscular strength as compared to an internal focus cue. Fitness coaches and therapists might consider integrating a specific attentional focus strategy when designing rehabilitation programs in subjects with obesity.

Improvements of Physical Activity Performance and Motivation in Adult Men through Augmented Reality Approach: A Randomized Controlled Trial

The COVID-19 pandemic had a global impact, increasing the prevalence of physical inactivity, which is mostly due to the lockdown and social distancing measures adopted during the pandemic. Hence, this study aimed to compare the efficacy of augmented reality-based training on physical activity performance and motivation in healthy adults to mirror visual feedback training and conventional physical therapy. This study used the randomized control trial pretest-posttest research design. Forty-eight healthy men aged 18–35 years who were engaged in recreational physical activities were enrolled and randomly divided into four groups: augmented reality-based training reality (ART), mirror visual feedback training (MVFT), therapist-based training (TBT), and control group. The total training program was held for four weeks. The isokinetic dynamometer, sit-and-reach test, Y balance test, and the intrinsic motivation inventory-22 were used to measure the outcomes before and after the intervention. Paired sample t-test was used to compare the changes before and after the intervention within groups, while the one-way ANOVA was used for the comparison between the groups. Results of the study showed that, after four weeks of intervention, balance, muscle strength, and muscle endurance in all groups significantly improved except for the control group. The ART group showed the highest increase in muscle strength, muscle endurance, and balance compared to the other groups. The motivation level increased in all three feedback groups and was observed in the following order: ART group > MVFT group > TBT group > control group. This study highlighted the most effective method that may be applied for home training during and after this period of the pandemic. The findings revealed that training while receiving real-time feedback via AR devices improves both physical performance and motivation. Augmented reality-based training can be used as an effective training option for improving physical activity and motivation and can be suggested for home training programs.

Variations in upper limb and trunk muscles activation during isometric exercises with or without exertion of control

BACKGROUND: Muscle activation during isometric contraction can be changed using an external-focus instruction method. OBJECTIVE: To explore and compare the activity of eight upper limb and trunk muscles during isometric chest squeeze exercises, performed in the same posture with and without the exertion of control to avoid crushing an object. METHODS: Muscle activation by an isometric chest squeeze with 45∘ shoulder abduction and forearm pronation was examined. Isometric chest squeeze exercises were performed while holding objects with maximum pressure, and with exerted control to avoid crushing the object Muscle activation was measured by surface electromyography. RESULTS: During the exercises performed while exerting control to avoid crushing the object the lower trapezius (p< 0.001) and latissimus dorsi (p= 0.03) showed significantly higher activity. During the exercises performed without control, the upper trapezius, serratus anterior, and pectoralis major showed significantly higher activity (p= 0.016, p< 0.001, p< 0.001, respectively). CONCLUSIONS: This novel isometric exercise can increase the scapular muscles in the intermediate range of the glenohumeral joint. Therefore, it may assist in improving sport performance, in preventing injuries and in rehabilitation following musculoskeletal injuries.

Acute and Long-Term Effects of Attentional Focus Strategies on Muscular Strength: A Meta-Analysis

This review aimed to perform a meta-analysis examining the following: (a) acute effects of adopting an internal focus vs. external focus of attention on muscular strength; and (b) long-term effects of adopting an internal focus vs. external focus of attention during resistance training on gains in muscular strength. We searched through five databases to find eligible studies. Random-effects meta-analyses of standardized mean differences were conducted to analyze the data. Ten studies were included. In the meta-analysis for the acute effects, there was a significant positive effect of external focus on muscular strength (standardized mean difference: 0.34; 95% confidence interval: 0.22, 0.46). In the meta-analysis for the long-term effects, there was no significant difference between training with an internal focus and external focus on muscular strength gains (standardized mean difference: 0.32; 95% confidence interval: –0.08, 0.73). In the subgroup analysis for lower-body exercises, we found a significant positive effect of training with an external focus on muscular strength gains (standardized mean difference: 0.47; 95% confidence interval: 0.07, 0.87). In summary, our findings indicate an acute increase in muscular strength when utilizing an external focus of attention. When applied over the long-term, using an external focus of attention may also enhance resistance training-induced gains in lower-body muscular strength.

Gait Retraining With Real-Time Visual Feedback to Treat Patellofemoral Pain in Adult Recreational Runners: A Critically Appraised Topic

Clinical Scenario: Patellofemoral pain (PFP) is a common knee injury in recreational adult runners, possibly caused by faulty mechanics. One possible approach to reduce this pain is to retrain the runner's gait. Current research suggests that no definitive gold standard treatment for PFP exists. Gait retraining utilizing visual feedback may reduce PFP in both the short and long term. Clinical Question: In adult runners diagnosed with PFP, does gait retraining with real-time visual feedback lead to a decrease in pain? Summary of Key Findings: A literature search was performed; 3 relevant studies utilizing gait retraining with visual feedback, pain level as an outcome measure, and follow-up measures of at least 1 month after the intervention were included. All the included studies reported a decrease in short- and long-term pain for participants following visual feedback gait retraining. In addition, biomechanical measures related to PFP, including peak hip adduction angle and the angle of contralateral pelvic drop, improved after the completion of the intervention. Clinical Bottom Line: There is level 2 evidence supporting the implementation of 8 sessions over 2 weeks of visual feedback gait retraining as a means of treating patients diagnosed with PFP. Based on current available evidence, clinicians should identify faulty mechanics of patients and implement a protocol of increasing real-time visual feedback over the first 4 sessions and decreasing visual feedback over the final 4 sessions. Strength of Recommendation: Level 2.

Effects of mirror feedback during balanced exercise performance in the old people with mild cognitive impairment

Unbalanced movements between the bilateral sides may lead to dyskinesia and reduced motor function. The upper limbs are the most complex joints with different rate of usage between the limbs. The dominant side is repeatedly used more than the contralateral side for better dexterity and musculoskeletal utility. Such imbalance between the two bilateral sides may lead to further difference in movement ability. This study aimed to observe the feasibility of the mirror feedback method in the upper limb movements in the old people with mild cognitive impairment. Twenty-seven-old people with history of stroke were selected. Motion sensors were used to assess the location and motion of two limbs in synchronized lateral raise that include the abduction and adduction motions during the mirror feedback and no feedback trials. The results of the mirror feedback showed comparatively similar motions between the left and right upper limbs. The results of the study may indicate possible recommendation of mirror feedback method for synchronizing exercise motion of the upper limbs for the old people with mild cognitive impairment.