Miřátský, P, Hank, M, Gryc, T, Brožka, M, Cabell, L, Escamilla, R, Zahálka, F, and Malý, T. Fitness differences among professional firefighters utilizing various conditioning regimens throughout the year. J Strength Cond Res 39(7): e898-e908, 2025-The aim of this study was to compare selected parameters of physical fitness of Czech frontline professional firefighters ( n = 92), who performed various physical activities according to their preferences within their regular physical preparation for 1 year. These firefighters were assigned to 1 of 3 groups based on their training preferences and sport focus: General Sports Activities (GSA; n = 30), Fire Sport (FS; n = 36), and Toughest Firefighter Alive (TFA; n = 26). All subjects completed (in period September) a battery of laboratory fitness tests including body composition, lower limb muscular strength and power, and cardiorespiratory fitness. Firefighters in the FS and TFA groups were found to have significantly higher values ( p < 0.01) for the following variables: fat-free mass, isokinetic strength, muscle power, maximum aerobic capacity, minute ventilation, and heart rate at the anaerobic threshold than their counterparts in the GSA group. There were no significant differences in body mass ( p = 0.21) and body mass index (BMI) ( p = 0.48) between the firefighter groups. Professional frontline firefighters' level of physical fitness is improved by the incorporation of specific physical training activities, duties, and disciplines. This can have a direct impact on frontline firefighters' capacity to fight fires safely and effectively.

• MeSH
• anaerobní práh fyziologie   MeSH
• dospělí MeSH
• hasiči * MeSH
• kardiorespirační zdatnost fyziologie   MeSH
• kondiční příprava * metody   fyziologie   MeSH
• lidé MeSH
• složení těla fyziologie   MeSH
• srdeční frekvence fyziologie   MeSH
• svalová síla fyziologie   MeSH
• tělesná výkonnost * fyziologie   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND: Muscle strength and postural control are essential components for performing daily living activities, particularly in older adults, and can therefore serve as screening tools for assessing fall risk in this population. METHODS: The aim of this quasi-experimental study was to evaluate the impact of a 12-week exercise intervention followed by a 2-week detraining period on lower limb strength and postural stability in older adults. The study involved 38 community-dwelling participants of Central European origin over 60 years of age. Participants underwent the measurements consisting of assessments of knee flexors and extensors strength (isokinetic dynamometer, 90° range of motion, 60°/s angular velocity, Humac Norm CSMI, Stoughton MA, USA), toe grip strength (toe grip dynamometer, Takei Scientific Instruments, Niigata, Japan), and postural stability (narrow stand, 30 s, Kistler, Switzerland). Testing was repeated three times during the study (pre-intervention, post-intervention, and post-detraining). Participants were separated into 3 groups according to the type of training: resistance training group (n = 13), proprioceptive training group (n = 14), and endurance training group (n = 11). The intervention program lasted 12 weeks, two 60-min sessions per week. A linear mixed model (LMM) predicted a change in postural stability after the resistance, proprioceptive, and endurance exercise interventions were applied. RESULTS: Results showed that knee extensor strength normalized to body mass significantly increased in the resistance training group post-intervention (p = 0.01). Toe grip strength was significantly higher after the intervention in the endurance training group (p = 0.02). A statistically significant increase in knee flexor strength was observed in the proprioceptive training group (p = 0.01). The 2-weeks detraining period revealed no statistically significant loss in training gains. The LMM found different predictions of postural stability changes related to knee extensor strength after each type of training intervention. The final LMM model explains well the variability of the dependent variable R2 = 0.866. CONCLUSIONS: These results highlight the unique characteristics of specific exercise interventions in enhancing muscular strength and postural stability, which are critical for fall prevention among older adults.

• MeSH
• časové faktory MeSH
• cvičení * fyziologie   MeSH
• dolní končetina * fyziologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• lineární modely MeSH
• odporový trénink * metody   MeSH
• posturální rovnováha * fyziologie   MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• svalová síla * fyziologie   MeSH
• terapie cvičením * metody   MeSH
• úrazy pádem prevence a kontrola   MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

PURPOSE: The present study aimed to investigate a) the associations between bilateral performance utilizing countermovement jump (CMJ), squat jump (SJ), speed and unilateral CMJ, isokinetic peak torque in knee extension and flexion with angular velocities of 60°/s and 180°/s and tensiomyography (TMG) parameters; b) whether the asymmetries derived from unilateral tests are associated with bilateral CMJ, SJ and speed in elite female soccer players. METHODS: Thirty-five elite female soccer players (average age: 20 ± 5 years) completed CMJ, SJ, speed, isokinetic muscle strength and TMG tests. RESULTS: Compared to the non-dominant leg, the dominant leg demonstrated greater peak torque output in both knee flexion (7.4%) and knee extension (5.6%) isokinetic tasks, as well as m. vastus medialis contraction time (7.6%), and soccer-specific agility test (4.1%). Conversely, the hamstring to quadriceps peak torque ratio at 180°/s (8.5%) was significantly greater in the non-dominant leg. The associations between CMJ, SJ and speed performance were positive and ranged from weak (r = 0.350) to high (r = 0.710). For speed and TMG-derived variables, correlations were negative and ranged from weak (r = -0.345, p = 0.042, for vastus medialis contraction time) to moderate (r = -0.530, p = 0.001, for biceps femoris contraction time). Furthermore, both bilateral CMJ and SJ negatively correlated with TMG-derived variables, ranging from weak (r = -0.350, p = 0.039, for vastus lateralis contraction time) to moderate (r = -0.537, p = 0.003, for rectus femoris contraction time). CONCLUSION: The overall significant, albeit inconsistent, correlations between the diverse performance scores obtained highlight the necessity for a multifaceted and thorough diagnostic strategy in female soccer players.

• Publikační typ
• časopisecké články MeSH

The phenomenon of post-activation performance enhancement plays an unidentified role in movement eccentric speed and individual muscle group responses. Therefore, this study aimed to determine whether the loaded front squat (FSq) speed of the eccentric phase would influence the post-activation performance enhancement effect and whether the FSq would elicit similar performance enhancement of knee flexion, knee extension, hip flexion, and hip extension muscles. Twenty resistance-trained handball players performed the FSq under maximum eccentric-concentric speed and 2-s eccentric speed (only the eccentric phase performed), while pre- and post-front squat countermovement jump, knee, and hip isokinetic flexion/extension performance were tested. The FSq conditioning activity was performed in a single set of three repetitions with either 90% (maximum eccentric-concentric speed) or 120% (2-s eccentric speed) of one repetition maximum, and post-performance was measured 4-12 min after the FSq. Athletes randomly changed the FSq eccentric speed and tested the hip or knee isokinetic flexion/extension strength at 180°/s. ANOVA showed that the rate of force development during the jump increased (Cohen d = 0.59-0.77) with no differences between 2-s eccentric and maximum speed eccentric protocols. Isokinetic strength increased after the 2-s eccentric FSq in hip extension (d = 0.76-0.86), knee flexion (d = 0.74-0.88), and hip flexion (d = 0.82), with no differences in knee extension strength. After maximum eccentric-concentric speed, isokinetic strength increased in hip extension (d = 1.25). In conclusion, the FSq conditioning activity enhances hip extensors' performance more than knee extensors' performance. Different eccentric types of muscle action during a conditioning activity alter the level of local muscle enhancement.

• Publikační typ
• časopisecké články MeSH

In light of previous research highlighting the prevalence of asymmetries in soccer players and possible links to injury risks, there is a crucial gap in the biomechanical understanding of complex relationships between lower extremity and trunk asymmetries in elite soccer players. The purpose of this study was to investigate the level, relationships, and differences among twelve different parameters of strength, morphological, and neuromuscular asymmetries in elite soccer players. Methods: Elite male soccer players (n = 25, age 21.7 ± 3.9 years) were tested in the following tests: bilateral fluid distribution, hip flexor range of motion, postural stability, isokinetic strength of knee extensors and flexors, isometric lateral trunk rotation strength, eccentric strength of knee flexors, isometric bilateral strength of hip adductors, and vertical ground reaction force in counter-movement jump-free arms, counter-movement jump, squat jump, and drop jump tests. One-way ANOVA, Pearson's coefficient (r), and partial eta squared (ηp2) were used for data analysis. Results: Significant differences in asymmetries were found in elite soccer players (F11,299 = 11.01, p < .01). The magnitude of asymmetry over 10% was in postural stability and drop jump parameters. The lowest magnitudes of asymmetries were in the fluid distribution of the lower limbs and the vertical ground reaction force during the take-off phase in squat jumps. The highest asymmetries between the dominant and non-dominant sides were found in postural stability and drop jump. A total of eleven significant correlations (p < 0.05, r = 0.41-0.63, R2 = 0.17-0.40) were detected between the analyzed asymmetries in elite soccer players. The lateral trunk rotation asymmetries were significantly correlated to vertical ground reaction force asymmetries and knee extensors. Conclusion: Long-term exposure in elite soccer leads to unilateral biomechanical loading that induces abnormal strength and morphological adaptations in favor of the dominant side while linking lower limb and trunk strength asymmetries. By unraveling these complex relationships, we strive to contribute novel methods that could inform targeted training regimens and injury prevention strategies in the elite soccer community. The data should encourage future researchers and coaches to monitor and develop trunk strength linked to lower body kinematics.

• Publikační typ
• časopisecké články MeSH

Kolinger D, Stastny P, Pisz A, Krzysztofik M, Wilk M, Tsoukos A, and Bogdanis GC. High-intensity conditioning activity causes localized postactivation performance enhancement and nonlocalized performance reduction. J Strength Cond Res 38(1): e1-e7, 2024-This study aimed to examine whether a conditioning activity (CA) performed by the legs (barbell back squat) may cause postactivation performance enhancement (PAPE) on muscle groups other than leg extensors in isokinetic (eccentric [ECC] and concentric [CON]) and dynamic movement. Twelve male basketball players (age: 21.3 ± 3.2, body mass: 89.6 ± 14.1 kg, height: 187.4 ± 4.6 cm, and 1 repetition maximum (1RM) barbell back squat: 113 ± 21 kg) with previous resistance-training experience of at least 2 years, performed 3 sets of 3-4 repetitions of back-squats with submaximal load (60, 90, and 90% 1RM) as CA. Before and after the CA, they performed pretest and post-test in the form of countermovement jumps (CMJs) (localized) or explosive push-ups (EPUs) (nonlocalized) along with isokinetic flexion and extension at the knee (localized) or at the elbow (nonlocalized). The localized and nonlocalized protocols were divided into 2 days in a randomized order. The back squat as CA significantly increased peak torque (PT) (p < 0.05) in all CON and ECC muscle actions and average power per repetition (APPR) (p < 0.05) (all muscle actions except ECC flexion) of the localized isokinetic tests with large (>0.8) and medium (0.4-0.79) effect sizes and significantly decreased (p < 0.01) the PT and APPR (p < 0.01) of the nonlocalized isokinetic test in the ECC flexion. The CMJ and EPU tests showed no significant differences (p > 0.05) between premeasures and postmeasures of take-off height. The effect of PAPE seems to be specific to the muscles most involved in the CA, and the CA inhibits PT of subsequent muscle ECC contractions in muscles not involved in the CA.

• MeSH
• dospělí MeSH
• kolenní kloub MeSH
• koleno MeSH
• kosterní svaly fyziologie   MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• odporový trénink * metody   MeSH
• svalová síla * fyziologie   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

Background: Objective criteria to accurately evaluate the ability of a patient to make a risk-free return to their previous level of activity after anterior cruciate ligament reconstruction (ACLR) and to progress through stages of the rehabilitation process are still widely discussed. Objective: The goal of the study was to investigate the functional status of non-elite football players 6 months after ACLR based on the Functional Movement Screen test (FMS) and side-to-side differences of isokinetic quadriceps and hamstring peak torque between the operated (OP) and non-operated (NOP) extremities. Methods: A total of 35 football players (male:female ratio 31:4, mean age 24.7 ± 2.8 years) who had undergone primary and isolated ACLR were assessed 6 months (mean 6.1 ± 2.6) after surgery. Functional performance evaluation included the FMS test and isokinetic quadriceps/hamstring peak torque values examined using the Biodex Testing System at angular velocities of 60 deg/s and 180 deg/s. In addition, side-to-side differences for flexion and extension at both angular velocities were calculated by the limb symmetry index. Results: In the functional assessment, the overall score of the FMS test was 15.34 ± 2.60. Moreover, inter-extremity differences in all isokinetic strength tests were statistically significant. Isokinetic strength peak torques of quadriceps and hamstring of NOP were significantly higher than those of OP at both angular velocities (p < .001). The limb symmetry index results for recorded peak torques at 60 deg/s were 75% in extension and 88% in flexion and at 180 deg/s were 79% in extension and 86% in flexion. Conclusion: The presented data indicate explicit inter-extremity muscles strength differences and disturbances in global movement patterns after ACLR. Delayed recovery of muscle strength and disparities between the OP and NOP limbs 6 months after ACLR may undermine the patient's readiness to return to preoperative activity.

• MeSH
• čtyřhlavý sval stehenní MeSH
• dospělí MeSH
• fotbal zranění   MeSH
• lidé MeSH
• návrat ke sportu MeSH
• posouzení stavu pacienta MeSH
• rekonstrukce předního zkříženého vazu * metody   rehabilitace   MeSH
• výsledek terapie MeSH
• zadní stehenní svaly MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• klinická studie MeSH

Heritability studies on sport-related traits accepted that endurance, speed, power, and strength abilities include an active genetic predisposition to elite soccer participation. This study evaluates the influence of selected genetic variants on performance in speed, power, and strength laboratory tests on a group of elite soccer players, including their playing position. A ninety-nine male elite soccer players were compared to controls (n = 107) and tested for quadriceps and hamstrings isokinetic strength at speed 60°/s, 180°/s, and 300°/s, jump performance, and genotypes of ACTN3 (R577X, rs1815739), ACE (I/D, rs1799752), NOS3 (Glu298Asp, rs1799983), AMPD1 (34C/T, rs17602729), UCP2 (Ala55Val, rs660339), BDKRB2 (+9/-9, rs5810761) and IL1RN (VNTR 86-bp). The ACTN3 XX homozygotes in defenders had lower quadriceps and hamstring isokinetic strength in all tested speeds than ACTN3 RX and RR genotypes (p < 0.05). The ACTN3 RR homozygotes in defenders had higher quadriceps strength in all tested velocities than the RX heterozygotes (p < 0.05). We also found other associations between playing-position in soccer and increased strength of lower limbs for AMPD1 CC and NOS3 Glu/Glu genotypes, and IL1RN*2 allele carriers. Total genetic score regression explained 26% of the variance in jump performance and isokinetic strength. The ACTN3 R allele, NOS3 Glu/Glu genotypes, and IL1RN*2 allele pre-disposed the attackers and defenders playing position in elite soccer, where those positions have higher strength and power measures than midfielders. Midfielders have lower strength and power conditions than other playing positions without relation to strength and power genes.

• Publikační typ
• časopisecké články MeSH

The purpose of our study was to investigate peak torque (PT) of knee extensors (KE) and knee flexors (KF), bilateral and unilateral strength asymmetries in isokinetic testing and vertical jump height (JH), vertical ground reaction force (VGRF), and force differences (ΔVGRF) between legs during different jump tests in professional first-line firefighters (n = 15) competing in fire sports disciplines. There was a significant effect of jump type on JH (F2,44 = 7.23, p < 0.05), VGRF (F2,44 = 16.03, p < 0.05), and ΔVGRF (F2,44 = 3.45, p < 0.05). Professional firefighters achieved a mean JH of 50.17 cm in the countermovement jump free arms and high PT of KEs (3.15 Nm/kg). No significant differences (p > 0.05) and small effect sizes (d < 0.3) were found between the legs when PTs were assessed. We found a slightly higher (d = 0.53) unilateral strength ratio in non-dominant legs (58.12 ± 10.26%) compared to dominant legs (55.31 ± 7.51%). No effect of laterality was found among limb comparisons, but a higher unilateral isokinetic strength ratio was found in non-dominant legs of firefighters. A high level of strength (PT of KEs > 3 times body weight) and vertical jump performance is comparable to the performance of elite athletic populations.

• MeSH
• biomechanika MeSH
• hasiči * MeSH
• koleno MeSH
• lidé MeSH
• sporty * MeSH
• svalová síla MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

PURPOSE OF THE STUDY To compare the early clinical results of patients who had anterior cruciate ligament (ACL) reconstruction with peroneus longus allograft versus hamstring tendon autograft. MATERIAL AND METHODS Forty patients who underwent ACL reconstruction were included in the study. Patients were grouped by their graft preference. Lachman and Pivot-shift tests were performed to the patients. Laxity was measured by KT-1000 arthrometer test with 15, 20 and 30 pound power. The maximum force values of nonoperated knee and the operated knee were recorded with Cybex II isokinetic dynamometer (HUMAC) and compared to each other. International Knee Documentation Committee (IKDC) form, modified Lysholm and Cincinnati evaluation forms were compared between two groups. RESULTS Twenty patients included into peroneus longus allograft (Group 1) and 20 patients were included into hamstring autograft group (Group 2). The mean age of patients Group 1 and 2 were 34.25 ± 6.73, and 29.6 ± 4.55, respectively. No significant difference was noted between two groups at modified Lysholm, Cincinati and IKDC scores (p > 0.01). There was no statistically significant difference between the Lachman and Pivot hift levels (p > 0.01). No significant difference was found in KT-1000 device measurements between groups according to the performed techniques (p > 0.01). There was no statistically significant difference between Cybex extension-flexion 60 /sec measurement and extension 240 /sec measurement of the patients (p > 0.01). DISCUSSION Allografts can be preferred because of the advantages, such as lack of donor site morbidity, short operative time, large graft, small incision, minimal scar, good cosmetic appearance, less postoperative pain, less movement restriction, and less arthrofibrosis. However, there are disadvantages, such as disease transmission, low biocompatibility, immune response, long recovery time, and high cost. Although it is difficult to compare the stability and functionality of allografts and autografts because of the differences in graft processing, fixation methods, and surgical techniques in studies, similar clinical results are reported in long-term follow-ups CONCLUSIONS Graft preference is dependent on surgical experience, patient age, activity status, comorbidities, presurgical status, and patient decision. Allograft ACL reconstruction is a good alternative to arthroscopic ACL reconstruction performed with hamstring tendon graft. Key words: anterior cruciate ligament, peroneus longus allograft, hamstring autograft, ACL reconstruction.

• MeSH
• alografty MeSH
• autologní transplantace MeSH
• kolenní kloub chirurgie   MeSH
• lidé MeSH
• ligamentum cruciatum anterius chirurgie   MeSH
• poranění předního zkříženého vazu * chirurgie   MeSH
• rekonstrukce předního zkříženého vazu * MeSH
• šlachy hamstringů * MeSH
• výsledek terapie MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH