Change search
Refine search result
1 - 12 of 12
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Bjerkefors, Anna
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Tinmark, Fredrik
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Nilsson, Johnny
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, The Laboratory of Applied Sports Science (LTIV).
    Arndt, Anton
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Seated Double-Poling Ergometer Performance of Individuals with Spinal Cord Injury - A New Ergometer Concept for Standardized Upper Body Exercise2013In: International Journal of Sports Medicine, ISSN 0172-4622, E-ISSN 1439-3964, Vol. 34, no 2, p. 176-182Article in journal (Refereed)
    Abstract [en]

    This study aimed to evaluate biomechanics during seated double-poling exercises in individuals with spinal cord injury (SCI) and to compare these with those of able-bodied persons (AB). 26 participants volunteered for the study; 13 with SCI (injury levels C7-T12), and 13 AB. A seated double-poling ergometer (SDPE) was developed. 3-dimensional kinematics was measured and piezoelectric force sensors were used to register force in both poles for calculation of power during incremental intensities. Significantly lower power outputs, (143.2 ± 51.1 vs. 198.3 ± 74.9 W) and pole forces (137.1 ± 43.1 vs. 238.2 ± 81.2 N) were observed during maximal effort in SCI compared to AB. Sagittal upper trunk range of motion increased with intensity and ranged from 6.1–34.8 ° for SCI, and 6.9–31.3 ° for AB, with larger peak amplitudes in flexion for AB (31.4 ± 12.9 °) compared to SCI (10.0 ± 8.0 °). All subjects with SCI were able to exercise on the SDPE. Upper body kinematics, power and force outputs increased with intensity in both groups, but were in general, lower in SCI. In conclusion, the SDPE could be successfully used at low to high work intensities enabling both endurance and strength training for individuals with SCI

  • 2.
    Carlsson, Magnus
    et al.
    Dalarna University.
    Nilsson, Johnny
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control. Dalarna University.
    Hellström, John
    Halmstad University.
    Tinmark, Fredrik
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Carlsson, Tomas
    Dalarna University.
    The effect of ball temperature on ball speed and carry distance in golf drives2019In: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, ISSN 1754-3371, Vol. 233, no 2, p. 186-192Article in journal (Refereed)
    Abstract [en]

    The purpose of this study was to investigate the effect of ball temperature on impact ball speed and carry distance during golf drives in a blind randomized test design. The balls were exposed to a temperature-controlled environment (4?°C, 18?°C, 32?°C, and 46?°C) for 24?h prior to the test and each temperature group consisted of 30 balls. The 120 drives were performed by an elite male golfer (handicap: 0.0) in an indoor driving range. All drives were measured by a Doppler-radar system to determine the club-head speed, launch angle, spin rate, ball speed, and carry distance. Differences between the groups were investigated using a one-way analysis of variance. The results indicated that ball-speed and carry-distance differences occurred within the four groups (p?<?0.001 and p?<?0.01, respectively). The post hoc analyses showed that the ball temperatures of 18?°C and 32?°C had greater ball speeds and carry distances than balls at 4?°C and 46?°C (all p?<?0.05). The intervals for the between-group differences were 0.6?0.7?m?s?1 and 2.9?3.9?m for ball speed and carry distance, respectively. Hence, the results showed that ball temperature influences both the ball speed and the carry distance. Based on the findings in this study, standardization of ball temperature should be factored into governing body regulation tests for golf equipment.

  • 3.
    Carlsson, Tomas
    et al.
    Högskolan Dalarna.
    Nilsson, Johnny
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control. Högskolan Dalarna.
    Hellström, John
    Svenska golfförbundet.
    Tinmark, Fredrik
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Carlsson, Magnus
    Högskolan Dalarna.
    The effect of ball temperature on ball speed and carry distance in golf drives2018Conference paper (Other academic)
    Abstract [en]

    THE EFFECT OF BALL TEMPERATURE ON BALL SPEED AND CARRY DISTANCE IN GOLF DRIVES Carlsson, T.1, Nilsson, J.1,2, Hellström, J.3, Tinmark, F.2, Carlsson, M.1. 1: Dalarna University (Falun, Sweden), 2: The Swedish School of Sport and Health Sciences (Stockholm, Sweden), 3: The Swedish Golf Federation (Stockholm, Sweden). 

    Introduction

    Previously it was reported that golf-ball temperature has influence on the golf balls’ coefficient of restitution, impact duration, and maximal deformation (Allen et al., 2012). They concluded that their research was the first step in a process for determining the effect of temperature on a golf drive. However, how large influence the golf-ball temperature has on golf drives remains to be investigated. The purpose was to investigate the effect of ball temperature on impact ball speed and carry distance during golf drives in a blind randomized test design. 

    Methods

    The balls were exposed to a temperature-controlled environment (4°C, 18°C, 32°C, and 46°C) for twenty-four hours prior to the test, and each of the four different ball-temperature groups consisted of 30 balls. The 120 drives were performed by an elite male golfer (handicap: 0.0) in an indoor driving range. All drives were measured by a Doppler-radar system to determine club-head speed, launch angle, spin rate, ball speed, and carry distance. Differences between the four ball-temperature groups were investigate using a one-way analysis of variance. 

    Results

    The results indicate that there are ball-speed and carry-distance differences within the four ball-temperature groups (P &lt; 0.001 and P &lt; 0.01, respectively). The post-hoc analyses showed that the ball temperatures 18°C and 32°C had both greater ball speeds and carry distances compared to the balls in the ball-temperature groups 4°C and 46°C (all P &lt; 0.05); the intervals for the between-group differences were 2.0 to 2.4 km/h and 2.9 to 3.9 m for ball speed and carry distance, respectively.

    Conclusion

    The novel results of the current study show that the ball’s temperature has a significant effect on the ball speed after club-head impact and carry distance for drives performed by an elite golfer. The ball temperatures 18°C and 32°C gave significantly increased ball speeds and carry distances compared to the ball-temperature groups 4°C and 46°C. This knowledge could be used to maximise the carry distance and/or to minimise the carry-distance variability related to ball temperature.

    REFERENCES: Allen T, Bowley A, Wood P, Henrikson E, Morales E, James D. (2012) Procedia Eng, 34, 634-639.

  • 4. Gullstrand, Lennart
    et al.
    Halvorsen, Kjartan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Tinmark, Fredrik
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Eriksson, Martin
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Nilsson, Johnny
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Measurements of vertical displacement in running, a methodological comparison.2009In: Gait & posture, ISSN 1879-2219, Vol. 30, no 1, p. 71-75Article in journal (Refereed)
    Abstract [en]

    The aim was (1) to evaluate measurements of vertical displacements (V(disp)) of a single point on sacrum as an estimate of the whole body centre of mass (CoM) V(disp) during treadmill running and (2) to compare three methods for measuring this single point. These methods were based on a position transducer (PT), accelerometers (AMs) and an optoelectronic motion capture system. Criterion method was V(disp) of the whole body CoM measured with the motion capture system. Thirteen subjects ran at 10, 12, 14, 16, 18, 20 and 22kmh(-1) with synchronous recordings with the three methods. Four measurements of the (V(disp)) were derived: (1) V(disp) of CoM calculated from a segment model consisting of 13 segments tracked with 36 reflective markers, (2) V(disp) of the sacrum recorded with the PT, (3) V(disp) of the sacrum calculated from the AM, and (4) V(disp) of the sacrum calculated as the mid point of two reflective markers (sacrum marker, SM) attached at the level of the sacral bone. The systematic discrepancy between the measurements of sacrum V(disp) and CoM V(disp) varied between 0 and 1.5mm and decreased with increasing running velocity and decreasing step duration. PT and SM measurements showed strong correlation, whereas the AM showed a variability increasing with velocity. The random discrepancy within each subject was 7mm for all three methods. In conclusion single-point recordings of the sacrum V(disp) may be used to monitor changes in V(disp) of CoM during treadmill running.

  • 5.
    Halvorsen, Kjartan
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Eriksson, Martin
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Gullstrand, Lennart
    Tinmark, Fredrik
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Nilsson, Johnny
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Minimal marker set for center of mass estimation in running.2009In: Gait & Posture, ISSN 0966-6362, E-ISSN 1879-2219, Vol. 30, no 4, p. 552-555Article in journal (Refereed)
    Abstract [en]

    The purpose was to study the validity of a recently proposed method [Forsell C, Halvorsen K. A method for determining minimal sets of markers for the estimation of center of mass, linear and angular momentum. Journal of Biomechanics 2009;42(3):361-5] for estimating the trajectory of the whole-body center of mass (CoM) in the case of running at velocities ranging from 10 to 22 kmh(-1). The method gives an approximation to the CoM using the position of fewer markers on the body than the standard method of tracking each segment of the body. Fourteen male athletes participated. A standard method for determining the CoM from a model of 13 segments and using the position of 36 markers was used as reference method. Leave-one-out cross-validation revealed errors that decreased with increasing number of markers used in the approximative method. Starting from four markers, the error in absolute position of the CoM decreased from 15mm to 3mm in each direction. For the velocity of the CoM the estimation bias was neglectable, and the random error decreased from 0.15 to 0.05 ms(-1). The inter-subject and intra-subject variability in the estimated model parameters increased with increasing number of markers. The method worked well also when applied to running at velocities outside the range of velocities in the data used to determine the model parameters. The results indicate that a model using 10 markers represents a good trade-off between simplicity and accuracy, but users must take into account requirements of their specific applications.

  • 6. Halvorsen, Kjartan
    et al.
    Tinmark, Fredrik
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Arndt, Anton
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    The concept of mobility in single- and double handed manipulation.2014In: Journal of Biomechanics, ISSN 0021-9290, E-ISSN 1873-2380, Vol. 47, no 14, p. 3569-3573Article in journal (Refereed)
    Abstract [en]

    The concept of mobility describes an important property of the human body when performing manipulation tasks. It describes, in a sense, how easy it is to accelerate a link or a point on the manipulator. Most often it is calculated for the end-link or end-point of the manipulator, since these are important for the control objective of the manipulator. Mobility is the inverse of the inertia experienced by a force acting on the end-point, or a combined force and torque acting on the end-link. The concept has been used in studies of reaching tasks with one arm, but thus far not for bi-manual manipulation. We present here the concept for both single-handed and double-handed manipulation, in a general manner which includes any type of grip of the hands on the object. The use of the concept is illustrated with data on the left and right arm in a golf swing.

  • 7.
    Nilsson, Johnny
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Tinmark, Fredrik
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Halvorsen, Kjartan
    Arndt, Anton
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Kinematic, kinetic and electromyographic adaptation to speed and resistance in double poling cross country skiing2013In: European Journal of Applied Physiology, ISSN 1439-6319, E-ISSN 1439-6327, Vol. 113, no 6, p. 1385-1394Article in journal (Refereed)
    Abstract [en]

    This study incorporated variations in speed and the horizontal resistance acting upon elite female skiers during double poling (DP) on a treadmill and specifically analyzed biomechanical adaptations to these variations. Whole body kinematics and pole force data were recorded and used to calculate the moment of force acting on the shoulder and elbow joints. Data were obtained with a 3D optoelectronic system using reflective markers at given anatomical landmarks. Forces along the long axis of the right pole were measured with a piezoelectric force transducer. Surface electrodes were used to record EMG activity in the rectus femoris, rectus abdominis, latissimus dorsi and triceps brachii muscles. In a first set of recordings, the participants double poled with zero elevation at five different speeds from 8 to 17 km h−1. In a second set of recordings, horizontal resistance was added by weights (0.4–1.9 kg) attached to a pulley system pulling the skier posteriorly during DP at 14 km h−1. Results showed increasing relative duration of the thrust phase with increasing resistance, but not with speed. Significant kinematic differences occurred with increase in both speed and resistance. The mean (±SD) horizontal force components ranged between 1.7 (±1.3) and 2.8 (±1.1) percent (%) bodyweight (BW) in the speed adaptation and 3.1 (±0.6) and 4.0 (±1.3) % BW in the adaptation to horizontal resistance. Peak muscle activity showed a central to peripheral (proximo-distal) activation sequence. The temporal cycle phase pattern in the adaptation to speed and horizontal resistance differed.

  • 8.
    Tinmark, Fredrik
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control. Karolinska institutet, Inst för klinisk vetenskap, intervention och teknik / Dept of Clinical Science, Intervention and Technology.
    Bimanual movement control: insights from golf ball striking2014Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The aim of this thesis was to gain insight into the control of complex bimanual movements that are both fast and accurate. For this, skilled golf ball striking was used as a model in two experimental studies (I and III). The thesis also includes two methodological studies (II and IV), intended to assist in present and future investigation on bimanual movement control. Study I shows a common kinematic proximal-to-distal sequencing (PDS) pattern and speed-summation effect in skilled golf players of both genders. Using a common PDS movement strategy in golf ball striking at various endpoint speeds appears beneficial from mechanical and control points of view and could serve the purpose of providing both high speed and accuracy. In Study II a general expression for mobility was derived, which can be applied for extending the theory of mobility to double-handed grasping and manipulation. Study III found that kinematic contributions to endpoint velocity at slow, medium and fast test conditions were provided by the same subset of possible joint rotations. However, the specific subset differed between levels of expertise. The inertial behavior of the linkage arms-hands-club promoted movement parallel to and resisted movement orthogonal to the club path close to ball impact, at all endpoint speeds investigated. These findings extend previous knowledge regarding endpoint control in single-limb movements. Moreover, results regarding movement organization in Study I together with results in Study III regarding inertial behavior suggest the existence of limb configurations able to simultaneously exploit intersegmental dynamics and endpoint mobility in a proficient manner. To make the control of intersegmental dynamics in bimanual striking transparent, however, torques originating from segmental in teractions should be determined. However, when hands are placed next to each other or are overlapping it becomes challenging to find placements for standard force sensors which allow separation of right and left hand forces without altering normal behavior. As partially explored in Study IV, pressure mapping of the right hand together with inverse dynamics calculations for the golf club can potentially provide an adequate solution.

  • 9.
    Tinmark, Fredrik
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Ardt, Toni
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Ekblom, Maria
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Hellström, John
    Örebro universitet.
    Halvorsen, Kjartan
    Endpoint control in a bimanual striking task: application to the golfswing2014Article in journal (Refereed)
  • 10.
    Tinmark, Fredrik
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Arndt, Toni
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Halvorsen, Kjartan
    Using Motion Analysis and Pressure sensitive sensors for determining normal forces when gripping a cylinderManuscript (preprint) (Other academic)
  • 11.
    Tinmark, Fredrik
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Hellström, John
    Arndt, Anton
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Halvorsen, Kjartan
    Contributions to club velocity in golf swings to submaximal and maximal shot distances2012In: eProceedings of the 30th Conference of the International Society of Biomechanics in Sports, 2012: Volume 3 / [ed] Bradshaw, E.J., Burnett, A., Hume, P.A., 2012, p. 81-83Conference paper (Refereed)
    Abstract [en]

    The contribution of joint rotations to endpoint velocity was investigated in golf shots to submaximal and maximal shot distances using a 41degrees of freedom (DOF) kinematic model. A subset of 16 DOFs was found to explain 97%-99% of endpoint velocity regulation at club–ball contact. The largest contributors, for both groups at every shot condition, were pelvis and torso twist rotation among the most proximal DOFs, elbow pronation/supination and wrist flexion/extension among DOFs in the left arm, and shoulder internal/external rotation and wrist flexion/extension among DOFs in the right arm. The contributions from pelvis obliquity, left wrist flexion/extension, left wrist ulnar/radial deviation and right shoulder flexion/extension differed significantly between the advanced and intermediate group.

  • 12.
    Tinmark, Fredrik
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Hellström, John
    Örebro universitet.
    Halvorsen, Kjartan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Thorstensson, Alf
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Elite golfers' kinematic sequence in full-swing and partial-swing shots2010In: Sports Biomechanics, ISSN 1476-3141, Vol. 9, no 4, p. 236-244Article in journal (Refereed)
    Abstract [en]

    The aim of this study was to investigate whether kinematic proximal-to-distal sequencing (PDS) and speed-summation are common characteristics of both partial and full-swing shots in golf players of different skill levels and genders. A total of 45 golfers participated, 11 male tournament professionals, 21 male and 13 female elite amateurs. They performed partial shots with a wedge to targets at three submaximal distances, 40, 55 and 70 m, and full-swing shots with a 5 iron and a driver for maximal distance. Pelvis, upper torso and hand movements were recorded in 3D with an electromagnetic tracking system (Polhemus Liberty) at 240 Hz and the magnitude of the resultant angular velocity vector of each segment was computed. The results showed a significant proximal-to-distal temporal relationship and a concomitant successive increase in maximum (peak) segment angular speed in every shot condition for both genders and levels of expertise. A proximal-to-distal utilization of interaction torques is indicated. Using a common PDS movement strategy in partial and full-swing golf shots appears beneficial from mechanical and control points of view and could serve the purpose of providing both high speed and accuracy.

1 - 12 of 12
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf