Anabolic/Catabolic Hormone Imbalance but Still Jumping Further? Negative Association of Free Testosterone With Jumping Performance in Elite Handball Players Following a Preparatory Period.

Purpose: The present study investigated the effects of a 10-week preparatory training period on biomarkers and jumping performance and associations of changes in biomarkers, load, and jumping performance from the beginning (PRE) to the end of the preparatory period (POST) in elite handball players. Methods: Seventeen elite handball players competing in the first Slovenian men's League were recruited. Training, competition and academic loads were reported weekly, while biomarkers and jumping performance were assessed at PRE and POST. Results: At POST, decreased levels of free testosterone (large effect size [ES] = -1.69, p < .001) and free testosterone to cortisol ratio [FTCR] (large ES = -.95, p = .004) were observed; whereas, better performance on the single leg lateral hop test [SLLH] (large ES = .85, p = .007) and single leg triple hop test [SLTH] (large ES = 1.05, p = .002) were observed compared to PRE. Furthermore, changes in FTCR correlated with changes in cortisol (high r = -.751, p = .001), SLLH (moderate r = -.603, p = .022), and SLTH (moderate r = -.643, p = .013), while changes in free testosterone correlated with SLTH (moderate r = -.645, p = .013). Conclusions: High intensity trainings with a saturated competition schedule can result in disturbed anabolic/catabolic hormone ratio observed through FTCR decrease, which could indicate either an optimal state or early exhaustiveness. It seems that SLLH and SLTH are more sensitive to changes in biomarkers than a single leg hop test. Sport professionals may use the results for individualized monitoring of an athlete's health and performance, specifically, as an aid for adjusting training loads accordingly to prevent performance declines and potential injury/illness events.

Effects of Oral Iron Supplementation on Blood Iron Status in Athletes: A Systematic Review, Meta-Analysis and Meta-Regression of Randomized Controlled Trials.

BACKGROUND: Iron deficiency in athletes is initially treated with a nutritional intervention. If negative iron balance persists, oral iron supplementation (OIS) can be used. Despite the recent proposal for a refinement of treatment strategies for iron-deficient athletes, there is no general consensus regarding the actual efficiency, dosage, or optimal regimen of OIS. OBJECTIVE: The aim of this meta-analysis was to evaluate to what extent OIS affects blood iron parameters and physical performance in healthy adult athletes. METHODS: PubMed, Web of Science, PEDro, CINAHL, SPORTDiscus, and Cochrane were searched from inception to 2 November 2022. Articles were eligible if they satisfied the following criteria: recruited subjects were healthy, adult and physically active individuals, who used exclusively OIS, irrespective of sex and sports discipline. EXCLUSION CRITERIA: simultaneous supplementation with iron and any other micronutrient(s), intravenous iron supplementation or recent exposure to altitude acclimatisation. The methodological quality of included studies was assessed with the PEDro scale, the completeness of intervention reporting with the TIDieR scale, while the GRADE scale was used for quality of evidence synthesis. The present study was prospectively registered in PROSPERO online registry (ID: CRD42022330230). RESULTS: From 638 articles identified through the search, 13 studies (n = 449) were included in the quantitative synthesis. When compared to the control group, the results demonstrated that OIS increases serum ferritin (standardized mean difference (SMD) = 1.27, 95% CI 0.44-2.10, p = 0.006), whereas blood haemoglobin (SMD = 1.31, 95% CI - 0.29 to 2.93, p = 0.099), serum transferrin receptor concentration (SMD = - 0.74, 95% CI - 1.89 to 0.41, p = 0.133), and transferrin saturation (SMD = 0.69, 95% CI - 0.84 to 2.22, p = 0.330) remained unaltered. Following OIS, a trend of small positive effect on VO2max (SMD = 0.49, 95% CI - 0.09 to 1.07, p = 0.086) was observed in young healthy athletes. The quality of evidence for all outcomes ranged from moderate to low. CONCLUSIONS: Increase in serum ferritin concentration after OIS was evident in subjects with initial pre-supplementation serum ferritin concentration ≤ 12 µg/l, while only minimal, if any effect, was observed in subjects with higher pre-supplementation serum ferritin concentration. The doses of OIS, that induced a beneficial effect on hematological parameters differed from 16 to 100 mg of elementary iron daily, over the period between 6 and 8 weeks. Shorter supplementation protocols have been shown to be ineffective.

The influence of lifestyle interventions and overweight on infertility: a systematic review, meta-analysis, and meta-regression of randomized controlled trials.

This study aimed to investigate the effect of lifestyle intervention (LSI) on diagnosed infertility in overweight and obese women. A systematic review and meta-analysis were conducted. A literature search was performed on the following databases from September 2022 to December 2022: PubMed, Web of Science, and SPORTDiscus. The inclusion criteria were the following: women between 18 and 45 years of age, BMI over 25.0 kg/m2, diagnosed with infertility, a weight loss intervention, and control group part of RCTs. In total, 15 studies were identified and included. The meta-analysis shows a beneficial effect of LSI on reducing weight, waist circumference, and BMI and increasing infertility. A significantly beneficial effect of lifestyle intervention on weight reduction was observed for participants who initially had a higher BMI, while a non-significant effect was observed for individuals with a BMI above 35 kg/m2. The meta-analysis showed a beneficial effect of lifestyle intervention on ovulation incidence and sex hormone-binding globulin. The lifestyle intervention group had 11.23 times more ovulatory incidence than the control group, which in turn increased the ability to conceive. As robust evidence for the effect of lifestyle interventions on infertility in obese and overweight women was found, it is advised to integrate similar interventions into future infertility treatment processes.

The use of tensiomyography in older adults: a systematic review.

Introduction: Aging of skeletal muscles results in a cascade of events negatively affecting muscle mass, strength, and function, leading to reduced mobility, increased risk of falls, disability, and loss of independence. To date, different methods are used to assess muscle mechanical function, tensiomyography (TMG) being one of them. The aim of this review was twofold: to summarize the evidence-based usefulness of tensiomyography in older adults and to establish reference values for the main tensiomyography parameters in older adults. Methods: The PubMed, Web of Science, SPORTDiscus, and tensiomyography databases were searched from inception until 25 December 2022. Studies investigating older adults (aged 60+ years) that reported tensiomyography-derived parameters such as contraction time (Tc) and/or maximal displacement (Dm) were included. Methodological quality was assessed using the Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. Results: In total, eight studies satisfied the inclusion criteria. Tensiomyography has been used on different groups of older adults, including asymptomatic, master athletes, patients with peripheral arterial disease, and patients with end-stage knee osteoarthritis with a mean age of 71.5 ± 5.38 (55.7% male subjects). The most evaluated were leg muscles such as vastus lateralis (VL), gastrocnemius medialis (GM), and biceps femoris (BF). The present review demonstrates that tensiomyography is used to assess neuromuscular function in asymptomatic and diseased older adults. When compared to asymptomatic individuals, power master athletes, knee osteoarthritis patients, and patients diagnosed with peripheral arterial disease have the shortest Tc in BF, VL, and GM muscles, respectively. On the other hand, endurance master athletes showed the longest Tc in all three evaluated muscles. Less mobile, nursing-home residents showed higher Dm in VL and BF, while lower Dm in GM than the asymptomatic group. The knee osteoarthritis group showed the largest Dm in BF and VL while having the smallest Dm in GM. Conclusion: Tensiomyography can serve as a valuable tool for assessing neuromuscular function in older adults. The method is sensitive to muscle composition, architecture, and (pre) atrophic changes of the skeletal muscles and might be responsive to muscle quality changes in aging and diseased populations. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=402345, identifier CRD42023402345.

The effectiveness of unilateral isokinetic resistance training on cross-education is independent of contraction velocity: a case of female dorsiflexors and plantar flexors.

The large body of published literature has shown that the effects of strength training can transfer from trained to untrained homologous limb muscles after unilateral training. These effects on strength have been shown to be very specific to the type and speed of training contraction. The aim of this study was to investigate the effects of a 4-week unilateral slow and fast velocity isokinetic concentric training, to compare the effects, and thus investigate whether these effects are speed-specific. Forty-four healthy female students allocated to slow training, fast training, or control performed 12 isokinetic concentric-concentric plantar/dorsal flexors training sessions (3 × 4 weeks) using their nondominant leg. Participants in the two experimental groups showed statistically significant gains in strength in both the trained (ranging from 8 to 41%) and untrained leg (5-26%), thus showing cross-education on strength effects. The present study demonstrated that 4 weeks (12 training sessions) of unilateral isokinetic resistance training in the concentric mode improved the strength of contralateral, untrained homologous muscles to the same extent, regardless of the contraction velocity used in females. Furthermore, the amount of concentric overload (50% more than during 60°/s) did not appear to affect the increase in strength gains. Therefore, practitioners are encouraged to use both training speeds when strength gains in the contralateral leg are the primary goal. If the training time is limited, however, training with a higher contraction speed is recommended.

The reliability, validity and usefulness of the 30-15 intermittent fitness test for cardiorespiratory fitness assessment in military personnel.

The objectives of this study were to investigate the reliability, validity, and usefulness of the 30-15 intermittent fitness test (30-15IFT) in soldiers. The 34 infantry members of the Slovenian armed forces were recruited as participants. Participants performed the continuous incremental treadmill test (TR), a 2-mile run (2MR) test, and two 30-15IFT tests. Additionally, participants were divided into a highest-scoring group (HSG) and a lowest-scoring group (LSG) based on their scores on the Army Physical Fitness Test. A very high reliability ratings were observed for 30-15IFT measures, as follows: end-running speed (ERS) ERSIFT (ICC = 0.971), maximal heart rate (HRmax) HRmaxIFT (IC = 0.960), and maximal relative oxygen consumption (VO2max) VO2max-IFT (ICC = 0.975). Although 30-15IFT measures demonstrated high correlations (r = 0.695-0.930) to the same measures of TR test, ERS, HRmax and VO2max were higher in the 30-15IFT (p > 0.05). Furthermore, ERSIFT and predicted VO2maxIFT were higher in HSG compared to LSG, whereas HRmax did not differ. The results of this study show that the 30-15IFT test is a reliable, valid and useful tool for assessing cardiorespiratory fitness in the armed forces. Moreover, the ERS and predicted VO2max values derived from the 30-15IFT could be considered more sensitive markers of combat readiness than the parameters derived from the TR and 2MR tests.Trial registration number: NCT05218798.

Interventions for increasing return to sport rates after an anterior cruciate ligament reconstruction surgery: A systematic review.

Background: An injury followed by surgery poses many challenges to an athlete, one of which is rehabilitation, with the goal of returning to sport. While total restoration of physical abilities is a primary goal for most athletes, psychosocial factors also play an important role in the success of an athlete's return to sport (RTS). The purpose of this review was to examine the effectiveness of exercise and psychosocial interventions on RTS rates, which might be one of the most important outcomes for elite athletes. Methods: To carry out this review, PubMed, SAGE Journals, Web of Science, SPORTDiscus, ScienceDirect, and Google Scholar databases were searched from inception to July 2022. The inclusion criteria consisted exercise or psychosocial intervention for athletes after anterior cruciate ligament reconstruction (ACLR), with reporting RTS rates as an outcome. Results: From 1032 identified articles, four reports (N = 130) met inclusion criteria, all of which examined the recovery after ACLR. The mean MINORS score for the included studies was 16.3 ± 6.1, of which non-comparative studies scored 11.0 ± 1.4, while comparative studies scored 21.5 ± 0.7. There were consistent findings for benefits of exercise and psychosocial interventions on RTS rates. Return to preinjury rates in the reviewed studies vary between 63 and 95% with lower % observed in female athletes and with shorter follow-up. Interventional studies reporting RTS rates with a larger sample size and longer follow-up are needed. Conclusion: Physical and psychological function, as well as social support can be influenced by appropriate interventions, indicating future work on rehabilitation programs for return to preinjury might consider taking the holistic approach addressing those.

Reliability and validity of 30-15 intermittent fitness test for cardiorespiratory fitness assessment among infantry members of Slovenian armed forces: A study protocol.

Introduction: Cardiorespiratory fitness (CRF) testing is routinely performed by most armed and tactical forces around the world as part of their recruitment process for new members or simply as an annual examination of their personnel. A 2-mile run (2MR) test is among the most commonly used. However, as it is performed outdoors, weather, climate, and terrain can influence the results and often limit the maximum performance. Also, this test has been shown to be difficult for individuals because the pacing strategy is self-paced. As such, it does not reflect the real situation on the battlefield, where most activities are externally driven by the environment and the enemy. Therefore, we believe that the 30-15 Intermittent Fitness Test (30-15IFT) may be a suitable tool for measuring CRF and battle readiness of military personnel. Moreover, given the importance of visual attention to military personnel we aim to investigate the differences in visual attention between better and less physically prepared infantry members and its corresponding response to maximal endurance running test. Methods and analysis: This randomized cross-over study using a within-subjects test-retest design will enroll 32 infantry members of the Slovenian Armed Forces. To investigate the reliability and validity of the 30-15IFT test, an incremental treadmill test (TR), a 2MR test, and two identical 30-15IFT will be performed in randomized order. Additionally, participants will be subsequently divided into two groups based on their score on the Army Physical Fitness Test (APFT), whereas differences in visual attention will be assessed by using the d2 test. The primary analysis will assess differences in key physiological outcomes between the different CRF tests (TR vs. 2MR vs. 30-15IFT). In addition, the relative reliability of all dependent variables between two 30-15IFT trials will be estimated by interclass correlation coefficient (ICC), while relationship between maximal oxygen uptake, heart rate and maximal running speed of 30-15IFT, TR and 2MR will be assessed using Pearson's correlation. Ethics and dissemination: Ethical approval was obtained from the National Medical Ethics Committee (reference number: 0120-495/2021/6). The results of the proposed study will be disseminated through publication in peer-reviewed journals. Clinical Trial Registration: [www.ClinicalTrials.gov], identifier [NCT05218798].

Impact of Motor-Cognitive Interventions on Selected Gait and Balance Outcomes in Older Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Background: Efficient performance of most daily activities requires intact and simultaneous execution of motor and cognitive tasks. To mitigate age-related functional decline, various combinations of motor and cognitive training have shown promising results. The aim of this systematic review and meta-analysis of randomized controlled trials (RCTs) was to evaluate the efficacy of different types of motor-cognitive training interventions (e.g., sequential and simultaneous) on selected functional outcomes in healthy older adults. Methods: Six online academic databases were used to retrieve eligible RCTs up to April 2021, following PRISMA guidelines and PICO criteria. A random-effects model was used for all meta-analyses conducted on selected functional outcomes: single- and dual-task gait speed, the Timed Up and Go Test (TUG), and Berg Balance Scale (BBS) score. Effect size (ES) was calculated as Hedges' g and interpreted as: trivial: <0.20, small: 0.20-0.60, moderate: 0.61-1.20, large: 1.21-2.00, very large: 2.01-4.00 or extremely large >4.00. Results: From 2,546 retrieved records, 91 RCTs were included for meta-analysis (n = 3,745 participants; 64.7-86.9 years). The motor-cognitive interventions included differed according to the type of training (e.g., sequential, simultaneous with additional cognitive task or exergame training. The results showed that motor-cognitive interventions can improve gait speed under single-task conditions (small ES = 0.34, P = 0.003). The effect of the intervention was moderated by the type of control group (Q = 6.203, P = 0.013): passive (moderate ES = 0.941, P = 0.001) vs. active controls (trivial ES = 0.153, P = 0.180). No significant effect was found for dual-task walking outcomes (P = 0.063). Motor-cognitive intervention had a positive effect on TUG (small ES = 0.42, P < 0.001), where the effect of intervention was moderated by control group [passive (moderate ES = 0.73, P = 0.001) vs. active (small ES = 0.20, P = 0.020)], but not by the type of training (P = 0.064). Finally, BBS scores were positively affected by motor-cognitive interventions (small ES = 0.59, P < 0.001) with however no significant differences between type of control group (P = 0.529) or intervention modality (P = 0.585). Conclusions: This study provides evidence for the effectiveness of various types of motor-cognitive interventions on performance-based measures of functional mobility in healthy older adults. With respect to significant effects, gait speed under single-task condition was improved by motor-cognitive interventions, but the evidence shows that this type of intervention is not necessarily more beneficial than motor training alone. On the other hand, motor-cognitive interventions are better at improving multicomponent tasks of dynamic balance and mobility function, as measured by the TUG. Because of substantial heterogeneity and the current limited availability of different types of interventions, the conclusions should be interpreted with caution.

The muscle contractile properties in female soccer players: inter-limb comparison using tensiomyography.

OBJECTIVE: The present study aimed to: i) determine the contractile properties of the major lower limb muscles in female soccer players using tensiomyography; ii) investigate inter-limb differences; and iii) compare inter-limb differences between different selections and playing positions. METHODS: A total of 52 female soccer players (A team; U19 and U17) were recruited. The vastus lateralis (VL), vastus medialis (VM), rectus femoris (RF), biceps femoris (BF), gastrocnemius medialis (GM), lateralis (GL) and tibialis anterior (TA) of both lower limbs were evaluated. RESULTS: When the entire sample was assessed regardless of selection or playing position, there were significant inter-limb differences in all measured muscles except BF. Compared to the non-dominant limb, the dominant limb had higher delay time in VL (p=0.008), while showing lower values in VM (p=0.023), GL (p=0.043) and GM (p=0.006). Contraction time was lower in the RF of the dominant limb (p=0.005) and VM (p=0.047), while showing higher values in VL (p=0.036) and TA (p<0.001) as compared to the non-dominant limb. CONCLUSION: Given the differences found between the limbs in the whole sample studied, it is necessary to examine both limbs to gather a more in-depth understanding of underlying mechanisms related to neuromuscular functions in female soccer players. LEVEL OF EVIDENCE: Prognostic study, Level II.

The Time Course of Quadriceps Strength Recovery After Total Knee Arthroplasty Is Influenced by Body Mass Index, Sex, and Age of Patients: Systematic Review and Meta-Analysis.

Introduction: For patients with osteoarthritis who have undergone total knee arthroplasty (TKA), quadriceps strength is a major determinant of general physical function regardless of the parameters adopted for functional assessment. Understanding the time course of quadriceps strength recovery and effectiveness of different rehabilitation protocols is a must. Therefore, the aim of this study was to: (i) determine the magnitude of maximal voluntary strength (MVS) loss and the time course of recovery of the quadriceps muscle following TKA, (ii) identify potential moderators of strength outcomes, and (iii) investigate whether different rehabilitation practices can moderate the strength outcomes following TKA, respectively. Design: General scientific databases and relevant journals in the field of orthopedics were searched, identifying prospective studies that investigated quadriceps' MVS pre-to post-surgery. Results: Seventeen studies with a total of 832 patients (39% males) were included. Results showed that in the early post-operative days, the involved quadriceps' MVS markedly declined, after which it slowly recovered over time in a linear fashion. Thus, the greatest decline of the MVS was observed 3 days after TKA. When compared to pre-operative values, the MVS was still significantly lower 3 months after TKA and did not fully recover up to 6 months following TKA. Furthermore, a meta-regression analysis identified that the variables, time point of evaluation, patient age, sex, and BMI, significantly moderate the MVS of the quadriceps muscle. Conclusion: The analyzed literature data showed that the decrease in strength of the involved quadriceps muscles following TKA is considerable and lasts for several months post-surgery. Therefore, we recommend to specifically target the strengthening of knee extensor muscles, preserve motor control, and apply appropriate nutrition to ensure a holistic quadriceps muscle recovery. Since age, sex, and BMI were found to be moderating factors in patients' recovery, further research should include specific analyses considering these moderators.

Tissue Flossing Around the Thigh Does Not Provide Acute Enhancement of Neuromuscular Function.

Nowadays, various methods are used for acute performance enhancement. The most recent of these is tissue flossing, which is becoming increasingly popular for both performance enhancement and rehabilitation. However, the effects of flossing on athletic performance have not been clearly demonstrated, which could be due to differences in the methodology used. In particular, the rest periods between the end of the preconditioning activity and the performance of the criterion task or assessment tools varied considerably in the published literature. Therefore, the present study aimed to investigate the effects of applying tissue flossing to the thigh on bilateral countermovement jump performance and contractile properties of vastus lateralis (VL) muscle. Nineteen recreational athletes (11 males; aged 23.1 ± 2.7 years) were randomly assigned to days of flossing application (3 sets for 2 min of flossing with 2 min rest between sets) with preset experimental pressure (EXP = 95 ± 17.4 mmHg) or control condition (CON = 18.9 ± 3.5 mmHg). The first part of the measurements was performed before and after warm-up consisting of 5 min of cycling followed by dynamic stretching and specific jumping exercises, while the second part consisted of six measurement points after flossing application (0.5, 3, 6, 9, 12, 15 min). The warm-up improved muscle response time (VL = -5%), contraction time (VL = -3.6%) muscle stiffness (VL = 17.5%), contraction velocity (VL = 23.5%), jump height (13.9%) and average power (10.5%). On the contrary, sustain time, half-relaxation time and take-off velocity stayed unaltered. Flossing, however, showed negative effects for muscle response time (F = 18.547, p < 0.001), contraction time (F = 14.899, p < 0.001), muscle stiffness (F = 8.365, p < 0.001), contraction velocity (F = 11.180, p < 0.001), jump height (F = 14.888, p < 0.001) and average power (F = 13.488, p < 0.001), whereas sustain time, half-relaxation time and take-off velocity were unaffected until the end of the study protocol regardless of condition assigned and/or time points of the assessment. It was found that the warm-up routine potentiated neuromuscular function, whereas the flossing protocol used in the current study resulted in fatigue rather than potentiation. Therefore, future studies aimed to investigate the dose-response relationship of different configurations of preconditioning activities on neuromuscular function are warranted.

Comparison of the Field-Based Intermittent Running Fitness Test 30-15 and the Treadmill Multistage Incremental Test for the Assessment of Cardiorespiratory Fitness in Elite Handball Players.

The aim of the present study was to investigate whether the physiological parameters indicative of cardiorespiratory fitness obtained during the 30-15 intermittent fitness (30-15IFT) test and the multistage laboratory treadmill endurance (TR) test differ. Nineteen elite handball players were recruited for the current study and assigned in a cross-over manner to one of two tests to be performed 48 h apart at each visit to the testing facility. The results showed that VO2max (percentage difference [PC] = 6.1%; p = 0.004) and maximal running velocity (V) (PC = 19.4%; p < 0.001) were significantly higher for the 30-15IFT test than that obtained during the TR test. Furthermore, the onset of blood lactate accumulation was shown to be significantly higher for all measures considered to predict it during 30-15IFT compared to TR as follows: VO2max (PC = 12.6%; p = 0.001), running speed (PC = 33.9%; p < 0.001), and maximal heart rate (PC = 7.5%; p < 0.001). The current study highlights the importance of sport-specific testing, particularly for measuring individual cardiorespiratory fitness in elite handball players, as TR may underestimate crucial variables used for both diagnostics and training prescription.

Motor Imagery and Action Observation as Appropriate Strategies for Home-Based Rehabilitation: A Mini-Review Focusing on Improving Physical Function in Orthopedic Patients.

Dynamic stability of the knee and weakness of the extensor muscles are considered to be the most important functional limitations after anterior cruciate ligament (ACL) injury, probably due to changes at the central (cortical and corticospinal) level of motor control rather than at the peripheral level. Despite general technological advances, fewer contraindicative surgical procedures, and extensive postoperative rehabilitation, up to 65% of patients fail to return to their preinjury level of sports, and only half were able to return to competitive sport. Later, it becomes clear that current rehabilitation after knee surgery is not sufficient to address the functional limitations after ACL reconstruction even years after surgery. Therefore, new therapeutic tools targeting the central neural system, i.e., the higher centers of motor control, should be investigated and integrated into current rehabilitation practice. To improve motor performance when overt movement cannot be fully performed (e.g., due to pain, impaired motor control, and/or joint immobilization), several techniques have been developed to increase physical and mental activation without the need to perform overt movements. Among the most popular cognitive techniques used to increase physical performance are motor imagery and action observation practices. This review, which examines the available evidence, presents the underlying mechanisms of the efficacy of cognitive interventions and provides guidelines for their use at home.

Lower-Limb Muscle Contractile Properties, Explosive Power and the Subjective Response of Elite Soccer Players to the COVID-19 Lockdown.

The present study examined the effects of the lockdown period on basic anthropometric measures, countermovement jumping performance, skeletal muscle contractile properties derived from tensiomyography (TMG), injury incidence, and self-assessed general well-being in elite soccer players. A total of 266 players were assessed before (PRE) and 32 players were reassessed 11 days after (POST) the COVID-19 period. Significant changes in the TMG parameters were observed POST compared to PRE: contraction time (Tc) increased from 6% to 50% in vastus lateralis [VL] (p = 0.009) and biceps femoris [BF] (p < 0.001), respectively; whereas radial displacement (Dm) increased for 19% in BF (p = 0.036) and 17% in VL (p < 0.001), respectively. Jumping performance remained unchanged from PRE to POST In addition, athletes rated the lockdown period as a positive event and felt psychologically better during the lockdown, primarily because they spent more time with family members and friends. Although there were no differences in any of the variables describing lower limb muscle power following the two-month lockdown, the altered contractile properties of the assessed muscles suggest suboptimal conditioning of the football players.

Combining physical and virtual worlds for motor-cognitive training interventions: Position paper with guidelines on technology classification in movement-related research.

Efficient movements require intact motor and cognitive function. There is a growing literature on motor-cognitive interventions to improve the overall quality of life of healthy or diseased older people. For such interventions, novel technological advances are crucial not only in terms of motivation but also to improve the user experience in a multi-stimuli world, usually offered as a mixture of real and virtual environments. This article provides a classification system for movement-related research dealing with motor-cognitive interventions performed in different extents of a virtual environment. The classification is divided into three categories: (a) type of digital device with the associated degree of immersiveness provided; (b) presence or absence of a human-computer interaction; and (c) activity engagement during training, defined by activity >1.5 Metabolic Equivalent of task. Since virtual reality (VR) often categorizes different technologies under the same term, we propose a taxonomy of digital devices ranging from computer monitors and projectors to head-mounted VR technology. All immersive technologies that have developed rapidly in recent years are grouped under the umbrella term Extended Reality (XR). These include augmented reality (AR), mixed reality (MR), and VR, as well as all technologies that have yet to be developed. This technology has potential not only for gaming and entertainment, but also for research, motor-cognitive training programs, rehabilitation, telemedicine, etc. This position paper provides definitions, recommendations, and guidelines for future movement-related interventions based on digital devices, human-computer interactions, and physical engagement to use terms more consistently and contribute to a clearer understanding of their implications.

Dose-Response Relationship between Endurance Training Prescription Variables and Increases in Aerobic Performance of Healthy and Unhealthy Middle and Very Old Individuals Aged 70 Years and Older: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: The objectives of this systematic review and meta-analysis were to quantify the effectiveness of endurance training (ET) on aerobic performance (i.e., peak oxygen uptake (VO2peak)) in healthy and unhealthy middle and very old adults aged 70 years and older, and to provide dose-response relationships of training prescription variables (in terms of frequency, and volume). METHODS: Several scholarly databases (i.e., PubMed/MEDLINE, SpringerLink, ScienceDirect Journals, and Taylor & Francis Online-Journals) were searched, identifying randomized controlled studies that investigated the effectiveness of ET on VO2peak in older adults. Standardized mean differences (SMD) were calculated. RESULTS: In terms of changes differences between experimental and control group, ET produced significant large effects on VO2peak performance (SMD = 2.64 (95%CI 0.97-4.31)). The moderator analysis revealed that "health status" variable moderated ET effect onVO2peak performance. More specifically, ET produced larger SMD magnitudes on VO2peak performance in healthy compared with unhealthy individuals. With regard to the dose-response relationships, findings from the meta-regression showed that none of the included training prescription variables predicted ET effects on VO2peak performance. CONCLUSIONS: ET is an effective mean for improving aerobic performance in healthy older adults when compared with their unhealthy counterparts.

Home-based motor imagery intervention improves functional performance following total knee arthroplasty in the short term: a randomized controlled trial.

BACKGROUND: Motor imagery (MI) is effective in improving motor performance in the healthy asymptomatic adult population. However, its possible effects among older orthopaedic patients are still poorly investigated. Therefore, this study explored whether the addition of motor imagery to routine physical therapy reduces the deterioration of quadriceps muscle strength and voluntary activation (VA) as well as other variables related to motor performance in patients after total knee arthroplasty (TKA). METHODS: Twenty-six patients scheduled for TKA were randomized to either MI practice combined with routine physical therapy group (MIp) or to a control group receiving physical therapy alone (CON). MIp consisted of maximal voluntary isometric contraction (MViC) task: 15 min/day in the hospital, then 5 times/week in their homes for 4 weeks. MViC and VA of quadriceps muscle, knee flexion and extension range of motion, pain level, along with a Timed Up-and-Go Test (TUG) and self-reported measure of physical function (assessed using the Oxford Knee Score questionnaire [OKS]) were evaluated before (PRE) and 1 month after surgery (POST). RESULTS: Significantly better rehabilitation outcomes were evident on the operated leg for the MIp group compared to CON: at POST, the MIp showed lower strength decrease (p = 0.012, η2 = 0.237) and unaltered VA, significantly greater than CON (p = 0.014, η2 = 0.227). There were no significant differences in knee flexion and extension range of motion and pain level (p > 0.05). Further, MIp patients performed better in TUG (p < 0.001, η2 = 0.471) and reported better OKS scores (p = 0.005, η2 = 0.280). The non-operated leg showed no significant differences in any outcomes at POST (all p > 0.05). In addition, multiple linear regression analysis showed that failure of voluntary activation explained 47% of the quadriceps muscle strength loss, with no significant difference in perceived level of pain. CONCLUSION: MI practice, when added to physical therapy, improves both objective and subjective measures of patients' physical function after TKA, and facilitates transfer of MI strength task on functional mobility. TRIAL REGISTRATION: Retrospectively registered on ClinicalTrials.gov NCT03684148.

Muscle-specific changes of lower extremities in the early period after total knee arthroplasty: Insight from tensiomyography.

OBJECTIVE: This study aimed to evaluate changes in i) muscle contractile properties of both lower extremities by using tensiomyography (TMG); ii) patients' physical function, and iii) electromechanical efficiency (EME) of the gastrocnemius medialis muscle in total knee arthroplasty (TKA) patients from before to one-month after TKA. METHODS: Twenty-six patients scheduled for TKA were included. RESULTS: The significant muscle*time interaction was found for sustain time and maximal radial displacement (Dm) (η2≥0.219) only, whereas time*leg interaction was found for time delay and Dm (η2≥0.254) only. Post hoc analysis showed a significant decrease of Dm of vastus medialis and increase in contraction time (Tc) of both the vastus lateralis and rectus femoris muscles of the involved leg, respectively. Furthermore, reduction of knee extensors (-55.4%) and flexors (-22.2%) strength, timed up and go (-26.9%), 30s chair stand (-28.9%) and EME (-38.2%) was observed. CONCLUSION: TKA treatment altered physical function as well as contractile properties of the main skeletal muscles surrounding the involved joint in the early period after surgery; however, alterations showed to be both limb and muscle-specific. This might provide clinicians and physiotherapist with additional information on how to adapt rehabilitation to the needs of an individual patient.

Validation of the Oxford Knee Score and Lower Extremity Functional Score questionnaires for use in Slovenia.

BACKGROUND: With the increasing prevalence of total knee replacement (TKR) due to knee osteoarthritis, the absence of patient-reported outcome measures in Slovenia must be addressed. QUESTIONS/PURPOSES: (1) We cross-culturally adapted Oxford Knee Score (OKS) and Lower Extremity Functional Scale (LEFS) questionnaires to the Slovenian-speaking community. (2) We evaluated OKS and LEFS psychometric characteristics. PATIENTS AND METHODS: In the first assessment (Time 1) Slovenian versions of both questionnaires (OKS-Slo and LEFS-Slo), knee pain, timed-up to go (TUG) and sit to stand (STS) tests were completed by 123 subjects (55% females), of which 78 were patients scheduled for TKR and 45 were healthy age-matched controls. The questionnaires were assessed one week apart (Time 2) to investigate the test-retest reliability, with 121 subjects (98.4%) completing second measurements. RESULTS: Significant differences were observed between the two groups. Where patients had greater body mass index, they were slower in TUG, weaker in STS, had greater knee pain in both knees and scored lower on both questionnaires. Additionally, correlation analysis showed that OKS-Slo and LEFS-Slo correlated almost perfectly (correlation coefficient [CC] = .968, p < 0.001). Excellent negative correlations were observed with TUG (OKS-Slo/CC = - 0.679, p < 0.001; LEFS-Slo/CC = - 0.692, p < 0.001) and STS (OKS-Slo/CC = 0.790, p < 0.001; LEFS-Slo/CC = 0.815, p < 0.001) tests, while knee pain of affected leg correlated the most (OKS-Slo/CC = - 0.923, p < 0.001; LEFS-Slo/CC = - 0.915, p < 0.001). The Cronbach's alpha coefficient for both the OKS-Slo and LEFS-Slo ranged between 0.87 and 0.99, while the interclass correlation coefficient was excellent; i.e., 0.99. Finally, both questionnaires proved to be unidimensional measures. CONCLUSION: The Slovenian version of both questionnaires is feasible, valid and reliable for use in clinical studies including the older adult population in Slovenia. LEVEL OF EVIDENCE: Level III, Diagnostic-case-control study.