Piotr Tabor

Background: It is known that a firefighter’s uniform with all equipment will significantly increase the load on the lower limbs during landing. The higher landing height will also increase ground reaction forces. However, it is unknown what effect the firefighters’ experience (job seniority) will have on the load. Moreover, age-related changes in neuromuscular control, balance, and muscular strength may alter the way external loads are managed, potentially increasing susceptibility to overload. Objective: The present study aimed to evaluate the overload of the musculoskeletal system resulting from changing external conditions. Methods: The main study involved 171 firefighters divided into three age categories: up to 25 years (I _n=83 ), up to 44 years (II _n=38 ) and over 44 years (III _n=50 ). The subjects performed three landing on to the force platforms from two heights (0.5 m; 1.0 m) and in two types of clothes: sport and fire protection. For the evaluation of lower limb overloads, the value of generated ground reaction force relative to body weight (GRF/BW) of the participant and time of force affecting the locomotor system (amortization time) were evaluated (t > 1 BW). Results: Increasing the landing height from 0.5 m to 1 m resulted in a significant ( p < 0.001 ) increase in ground reaction forces. Furthermore, younger participants generated significantly greater forces ( p < 0.001 ). Performing the landing in protective clothing also resulted in increased load (p < 0.001). Furthermore, older firefighters had a longer ( p < 0.01 ) cushioning time at both landing heights and in both clothing. Conclusion and application: These results suggest that younger or less experienced firefighters may employ suboptimal landing strategies, increasing their injury risk.

Purpose The aim of this study was to compare the accuracy of two spine models: the broken curve model and a new four tangent circles model. The modification concerns the adaptation of data acquisition to kinematic methods used in, e.g., gait and running analysis. Method Plastic, movable spine model of human with flexible intervertebral disks (manufactured by Erler Zimmer GE3014) was used as the study material. Markers with a diameter of 5 mm were glued to each spinous process (from C₇ to L₅). The recording was performed with a 6-camera Vicon system. Two spine models were created: a broken curve model used, among others, in the Diers scanner, and an own model of 4 circles, similar to the model of circles used in X-ray and CT analysis. Results The errors in the position of the spinous processes were significantly smaller in the 4-circle model than in the broken curve model. They ranged from 0.01 to 6.5 mm in the lumbar section, from 0.004 to 3.1 mm in the thoracic section. The practical possibilities of using the four-circle model during the cinematographic analysis of gait and run should be checked. Conclusion The four-circle model is more accurate than the broken curve model and can be used in the cinematographic analysis of the human spine movement.

Study aim: Assessment of muscle strength levels in different age groups of Polish firefighters, taking into account the influence of body composition. The aim of this study was also to assess the balance of synergistic flexor and extensor muscle groups in selected joints as a compensatory factor that reduces the risk of injury. Material and methods: The study included 172 active professional firefighters from various centres across Poland were included in the analysis. The subjects were divided into three age categories: 20 to < 30 (I, n = 84), 30 to < 40 (II, n = 38), and 40 to < 50 years (III, n = 50). Measurements of torque were performed for 10 muscle groups: flexors and extensors in the main joints. Measurements were conducted in standard positions under static conditions. Results and conclusions: The significant decline in strength was observed, which could be due to a change in the proportion of FFM to FM in total body mass as a function of age. The most rapid decline in strength was observed in the lower limb muscles. Therefore, it is suggested to increase the intensity training of lower limb strength among the oldest firefighters. Furthermore, although no significant differences were found in the H/Q ratio between age groups, all participants demonstrated values below the norm, which may indicate a increased risk of knee instability in this occupational group. It is therefore suggested that the force proportion index should be one of the basic indicators of periodic preventive examinations assessing the physical fitness of firefighters.

Introduction: Postural defects are a serious problem in modern society. In research on the subject, it is indicated that parents should pay special attention to their children's body posture. Basic knowledge in the field of posture defects and prevention will help prevent and deal with postural defects in children.Objectives: The aim of the study is to design and determine the reliability of a questionnaire examining parents' knowledge of postural health.Material and methods: The questionnaire development process consisted of the following steps: content and face validation, as well as reliability analysis. The questionnaire contains items assessing parents' literacy of body posture and was conducted among 55 Polish parents of school-age children and adolescents.Results: Initial results (first test-retest) for 37 participants revealed substantial reliability (0.61 to 1.00), however, it was exhibited that modifications were needed for some specific questions. After revisions and retesting (second test-retest of 18 participants), the updated questionnaire demonstrated significantly improved reliability (Cohen's kappa coefficient ranged from 0.85 to 1.00).Conclusions: The developed questionnaire is valid in terms of face and content validity, as well as reliability for assessing parents' literacy of body posture, and can potentially be used in clinical trials and practical settings.

The relationship of muscle strength symmetry with the symmetry of dynamic activities such as vertical jump (CMJ) and with symmetry of ranges of motion is ambiguous. Therefore, the aim of the current investigation was to assess the relationship between the flexor/extensor strength ratio and the range of motion of the knee joints and VGRF during jump in a sample of young healthy men. The sample consisted of 64 healthy, active men. The flexor and extensor torques and ranges of active and passive mobility of both knee joints were measured. Vertical ground reaction force (VGRF) was measured using two platforms. There were no significant correlations between the symmetry of muscle strength and the symmetry of ranges of motion and the symmetry of the VGRF. Therefore, using the cluster analysis, 4 subgroups were distinguished due to the size of the flexor/extensor ratio (H/Q ratio). Significant differences were found in the level of strength of the knee flexors between the clusters. Detailed analysis of muscle strength symmetry and VGRF symmetry seem to confirm the Leading Joint Hypothesis theory of motion control in multi-joint systems. It was found that the process of controlling movement by the nervous system compensates for the small asymmetries in the level of muscle strength in the knee flexors and extensors, as well as small asymmetries of VGRF.

Background: This study assesses curved track effects on fatigue symmetry and lower limb muscle activity while taking maximum velocity running kinematics into account. Methods: Polish master class athletes were examined (age 24.6 ± 3.67 years, bm 78.9 ± 6.02 kg, and bh 186.1 ± 6.63 cm). The measurements were made on a 400 m synthetic surface athletics track. The DelSys 16 channel system was employed to measure the activity of the right and left leg muscles. The kinematic variables of the run were obtained using a 3-axis accelerometer built into the recorder. Results: The study revealed curved track effects on asymmetric muscle activity and running kinematics in the first two sections of the run. On the first curve, the symmetry index (SI) was 8.1%, while in on straight, it was 11.5%. Moreover, significantly lower values of the fatigue index b were found for the right limb (F_(3.36) = 6.504; p = 0.0152). Conclusions: A reduction of asymmetric muscle activity is linked with compensatory muscle stimulation triggered by the nervous system and with adjusting running kinematics to changing external conditions. Therefore, the main focus further research should be on the optimal interaction between stride length and frequency in relation to the muscle activity corresponding to the track geometry.

Introduction. This paper aimed to establish relationships between the level of functional and dynamic asymmetry in advanced and intermediate-level runners and running velocity. Furthermore, evaluation of dynamic symmetry (running and vertical jump) was made using indices, taking into account the continuous character of the signals of the ground reaction force and angular positions in individual joints of the lower limb. Material and methods. Symmetry was assessed in a group of 12 Polish elite female middle-distance runners for the following parameters: 1) strength of lower limb muscles, 2) impulse of the vertical component of the ground reaction force during a CMJ jump, and 3) kinematics of a 50-m run in a straight line. Results. More advanced athletes (group A) were significantly taller and stronger than the athletes with less training experience (B). They were also characterized by a significantly longer step, a more extended swing phase, and a shorter support phase. There were no statistically significant differences between groups A and B in the level of asymmetry. Running velocity was significantly influenced by muscle strength symmetry (b = −5.77; p < 0.01) and support phase time symmetry (b = −6.64; p < 0.03). A reduction in each of these indices leads to an increase in running velocity. Conclusion. No morphological or functional asymmetry was found in female middle-distance runners with different training experience.

Introduction . The aim of this study was to determine the correlations between the direction and velocity of the ball in volleyball spike. We adopted the hypothesis that the direction of an attack is dependent upon the arrangement of the pectoral girdles in the phase of flight. Material and methods. The research was carried out for four different types of attacks: from the left side of the court down the line (A) and in the cross-court direction (B) and from the right side in the same directions (C and D). Sixteen young volleyball players from a Sports Championship School run by the Polish Volleyball Federation were examined. Results . The analysis of the results showed different ball velocities in different attacks. The velocity was the lowest in attack B and the highest in attack D. Conclusions. The direction of attack was produced by hitting the ball in a non-central manner and by aligning the glenohumeral joints diagonally to the net.