Mitja Gerzevic
University of Primorska, Faculty of mathematics, natural sciences and information technologies, Faculty Member
University of Primorska, Science and Research Centre, Institute for Kinesiology Research, Head of the Laboratory for Kinesiology Research
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Papers by Mitja Gerzevic
declines in physical health and even cognitive functions. Based on random selection, 7 healthy older adult
men received computerized spatial navigation training, while 8 served as active controls during 14-day
BR. Greater post-BR declines were seen in normal and complex (dual-task) walking for the control as
compared to intervention group, suggesting that computerized spatial navigation training can successfully
moderate detrimental BR effects. Findings underline the generalization of cognitive-based intervention
to the motor domain and potentially support their use to supplement BR interventions (e.g., exercise and
nutrition).
this pilot study was to analyze the differences in knee joint net muscle torque between the HBS and LBS. Methods: One healthy male subject (180.0 cm, 76.0 kg, 26 years) performed 10 steady paced squats (5 HBS and 5 LBS) with additional weight (40.4 kg) to a 90° knee angle. Kinematic and kinetic data were gathered using a high-speed camcorder and a force plate, respectively. The maximal and average knee joint net muscle torques (Mmax and Mavg) were then calculated via 2-dimensional inverse dynamics. Results: A significantly greater Mavg was observed using the HBS technique ascompared to the LBS, both during the entire range of the squat (MavgHBS = 221.6 ± 5.1 Nm, MavgLBS = 203.3 ± 10.2 Nm; p = 0.026) as well as during the eccentric (MavgHBS =
226.0 ± 5.9 Nm, MavgLBS = 202.0 ± 14.0 Nm; p = 0.043) and concentric (MavgHBS = 216.2 ± 3.6 Nm, MavgLBS = 205.0 ± 7.9 Nm; p = 0.021) phase separately. Conclusions: It can be concluded that the lower Mavg during the LBS could be due to the load transfer to the hip joint, most likely because of the greater anterior tilt of the torso, which is a direct response to a lower and more posterior bar placement on the back to finally maintain an unchanged centre of mass. Confirmation of these findings in a larger sample would imply that the LBS could be a more appropriate squat technique when knee joint relief is desired.
(ISO) and eccentric (ECC) contraction (AL_H) was compared with the AL obtained with double interpolated twitch
method (AL_TW). Twenty-two male subjects participated in the study. They performed two sets of maximal voluntary
ISO leg extensions (knee 55°, hip 110°) immediately followed by an ECC contraction imposed by the hydraulic system.
After that the AL with the interpolated twitch method was measured. AL_TW was significantly higher than AL_H (P <
0.001). The intraclass correlation coefficient showed excellent repeatability and consistency (ICC 0.98, 0.96 and 0.86) of
hydraulic measurements (T_ISO, T_ECC and AL_H, respectively), yet the Spearman correlation coefficients were not
significant neither between AL_TW and all AL_H. Analysed hydraulic system seemed not suitable for AL measurements.
correlation between vertical jump parameters and results
of the maximal static voluntary contraction tests, in
four-year-old children. Ninety children were included in
the final analysis. Each child performed three vertical
counter-movement jumps, with normal hands` function
and with hands fixed, respectively. Additionally, each
of them performed three repetitions of the following
maximal static force measurements: ankle-, knee- and
elbow flexion, knee extension, and hand grip. The best of
three repetitions of each movement tasks was included
in the further statistical analysis. Statistically significant
differences (p < 0.05) were found for majority of the 17
ground reaction force parameters measured in both
jumps; but not for time parameters of the take-off action.
Correlation analysis showed low inter-relation between
static strength and jump-related parameters. Less than
half of comparisons reached the level of statistical
significance; Pearson correlation coefficients reaching
only between 0.20 and 0.45. Results showed significant
role of the hands in vertical jumping, while jump dynamics
is only marginally related to the static strength. At this
age, neuro-muscular and inter-segmental coordination
are probably of key importance, while strength plays a
supportive role.
about the decreasing amount of physical/sport activity of
children and adolescents, and consequently also about
the decline of motor abilities, especially endurance and
strength. Strength is one of the most important motor
skills (beside flexibility) for prevention of injuries of
muscles, joints, tendons and ligaments. The aim of this
paper was to review the characteristics of strength training
for children and adolescents, concerning the appropriate
choice of type, methods and organizational forms, issuing
from the characteristics of the developmental stages of a
child. A special emphasis was given on preventive aspects
of strength training. The review of the literature from this
field indicates that strength can be increased more than
40% in children and adolescents. Such improvements
are a consequence of enhanced neuro-muscular
activation and coordination, more than a consequence
of hypertrophy. Positive effects of strength training
are shown also as improved local endurance, positive
influence on body composition with less adipose tissue,
improved joint stability and improved strength of the
whole body and also in its preventive effects. Of course
all this effects could be achieved only with a properly planned, individually adapted and supervised training
program. It is always important to bear in mind also the
developmental specifics of children and adolescents, their
physical and emotional maturity and some principles of a
safe and effective strength training that are discussed in
the paper.
Introduction: Absenteeism among employees of the Slovenian wood industry is considered being relatively high. This paper presents a selection of results from an extensive survey. The focus of the results presented here is on descriptive statistics of absenteeism, stress, and environment. Statistical tests were used in order to gain an initial understanding of the differences among production workers, middle management, and top management.
Methods: 930 participants (61.4% males, and 38.6% females), employed at one out of seven Slovenian wood factories filled out a questionnaire. The questionnaire covered absenteeism, stress, and environmental factors. A differentiation was made in the results among wood production workers, middle management, and top management.
Results/conclusions: Absenteeism was the highest among wood production workers. Reasons given for absenteeism were respiratory diseases, muscular-skeletal diseases, and care for a family member. Interestingly, the workplaces were perceived as too humid, too dusty as well as exposing the workers to chemicals. These physical environmental parameters might be related to respiratory complains. The present results provide an initial understanding of the large variety of factors related to work absenteeism in the Slovenian wood industry. These results will provide a basis for interventions aimed at improving the working conditions of employees in the wood industry.
declines in physical health and even cognitive functions. Based on random selection, 7 healthy older adult
men received computerized spatial navigation training, while 8 served as active controls during 14-day
BR. Greater post-BR declines were seen in normal and complex (dual-task) walking for the control as
compared to intervention group, suggesting that computerized spatial navigation training can successfully
moderate detrimental BR effects. Findings underline the generalization of cognitive-based intervention
to the motor domain and potentially support their use to supplement BR interventions (e.g., exercise and
nutrition).
this pilot study was to analyze the differences in knee joint net muscle torque between the HBS and LBS. Methods: One healthy male subject (180.0 cm, 76.0 kg, 26 years) performed 10 steady paced squats (5 HBS and 5 LBS) with additional weight (40.4 kg) to a 90° knee angle. Kinematic and kinetic data were gathered using a high-speed camcorder and a force plate, respectively. The maximal and average knee joint net muscle torques (Mmax and Mavg) were then calculated via 2-dimensional inverse dynamics. Results: A significantly greater Mavg was observed using the HBS technique ascompared to the LBS, both during the entire range of the squat (MavgHBS = 221.6 ± 5.1 Nm, MavgLBS = 203.3 ± 10.2 Nm; p = 0.026) as well as during the eccentric (MavgHBS =
226.0 ± 5.9 Nm, MavgLBS = 202.0 ± 14.0 Nm; p = 0.043) and concentric (MavgHBS = 216.2 ± 3.6 Nm, MavgLBS = 205.0 ± 7.9 Nm; p = 0.021) phase separately. Conclusions: It can be concluded that the lower Mavg during the LBS could be due to the load transfer to the hip joint, most likely because of the greater anterior tilt of the torso, which is a direct response to a lower and more posterior bar placement on the back to finally maintain an unchanged centre of mass. Confirmation of these findings in a larger sample would imply that the LBS could be a more appropriate squat technique when knee joint relief is desired.
(ISO) and eccentric (ECC) contraction (AL_H) was compared with the AL obtained with double interpolated twitch
method (AL_TW). Twenty-two male subjects participated in the study. They performed two sets of maximal voluntary
ISO leg extensions (knee 55°, hip 110°) immediately followed by an ECC contraction imposed by the hydraulic system.
After that the AL with the interpolated twitch method was measured. AL_TW was significantly higher than AL_H (P <
0.001). The intraclass correlation coefficient showed excellent repeatability and consistency (ICC 0.98, 0.96 and 0.86) of
hydraulic measurements (T_ISO, T_ECC and AL_H, respectively), yet the Spearman correlation coefficients were not
significant neither between AL_TW and all AL_H. Analysed hydraulic system seemed not suitable for AL measurements.
correlation between vertical jump parameters and results
of the maximal static voluntary contraction tests, in
four-year-old children. Ninety children were included in
the final analysis. Each child performed three vertical
counter-movement jumps, with normal hands` function
and with hands fixed, respectively. Additionally, each
of them performed three repetitions of the following
maximal static force measurements: ankle-, knee- and
elbow flexion, knee extension, and hand grip. The best of
three repetitions of each movement tasks was included
in the further statistical analysis. Statistically significant
differences (p < 0.05) were found for majority of the 17
ground reaction force parameters measured in both
jumps; but not for time parameters of the take-off action.
Correlation analysis showed low inter-relation between
static strength and jump-related parameters. Less than
half of comparisons reached the level of statistical
significance; Pearson correlation coefficients reaching
only between 0.20 and 0.45. Results showed significant
role of the hands in vertical jumping, while jump dynamics
is only marginally related to the static strength. At this
age, neuro-muscular and inter-segmental coordination
are probably of key importance, while strength plays a
supportive role.
about the decreasing amount of physical/sport activity of
children and adolescents, and consequently also about
the decline of motor abilities, especially endurance and
strength. Strength is one of the most important motor
skills (beside flexibility) for prevention of injuries of
muscles, joints, tendons and ligaments. The aim of this
paper was to review the characteristics of strength training
for children and adolescents, concerning the appropriate
choice of type, methods and organizational forms, issuing
from the characteristics of the developmental stages of a
child. A special emphasis was given on preventive aspects
of strength training. The review of the literature from this
field indicates that strength can be increased more than
40% in children and adolescents. Such improvements
are a consequence of enhanced neuro-muscular
activation and coordination, more than a consequence
of hypertrophy. Positive effects of strength training
are shown also as improved local endurance, positive
influence on body composition with less adipose tissue,
improved joint stability and improved strength of the
whole body and also in its preventive effects. Of course
all this effects could be achieved only with a properly planned, individually adapted and supervised training
program. It is always important to bear in mind also the
developmental specifics of children and adolescents, their
physical and emotional maturity and some principles of a
safe and effective strength training that are discussed in
the paper.
Introduction: Absenteeism among employees of the Slovenian wood industry is considered being relatively high. This paper presents a selection of results from an extensive survey. The focus of the results presented here is on descriptive statistics of absenteeism, stress, and environment. Statistical tests were used in order to gain an initial understanding of the differences among production workers, middle management, and top management.
Methods: 930 participants (61.4% males, and 38.6% females), employed at one out of seven Slovenian wood factories filled out a questionnaire. The questionnaire covered absenteeism, stress, and environmental factors. A differentiation was made in the results among wood production workers, middle management, and top management.
Results/conclusions: Absenteeism was the highest among wood production workers. Reasons given for absenteeism were respiratory diseases, muscular-skeletal diseases, and care for a family member. Interestingly, the workplaces were perceived as too humid, too dusty as well as exposing the workers to chemicals. These physical environmental parameters might be related to respiratory complains. The present results provide an initial understanding of the large variety of factors related to work absenteeism in the Slovenian wood industry. These results will provide a basis for interventions aimed at improving the working conditions of employees in the wood industry.