Biomedical subjects

N Konttinen

Publications and source records attributed to N Konttinen.

9 recordsLinked to original sources

PubMed2006

Outcome after anaesthesia and emergency surgery in patients over 100 years old.

BACKGROUND: Deteriorated organ function and reduced stress response in very old patients may cause post-operative morbidity and mortality. We wanted to identify immediate and longer-term outcome after anaesthesia and surgery in the oldest of the old patients. METHODS: We analysed retrospectively anaesthesia and hospital records of patients who were over 100 years old when undergoing major emergency surgery in our hospital during 1990-2004. RESULTS: Altogether, 12 patients (median age 101 years) underwent 14 operations (nine for hip fracture, four for lower extremity circulatory problems and one for peritonitis). During anaesthesia, invasive arterial pressure was monitored in eight patients while central venous pressure (CVP) was monitored in only one patient. Spinal anaesthesia with bupivacaine was given as a continuous technique in six and as single-shot spinal anaesthesia in five cases. Both spinal (11) and general (3) anaesthesias were characterized by marked drops in arterial pressure. Haemodynamics was managed with intravenous (i.v.) fluids and vasopressors. Five patients had post-operative delirium. Mortality at 30 days, 6 months and 1 year was 25%, 42% and 50%, respectively. Within 15 days of the operation, three patients had died (pneumonia, cerebral infarction and myocardial infarction). Nine patients returned home and six of them lived in their pre-operative mental and physical state for at least a year. CONCLUSION: Independently of the anaesthetic method, marked drops in blood pressure occurred, requiring pharmacological intervention. We assume that in most of the patients, hypovolaemia explains the intra-operative haemodynamic instability. A 25%, 30-day mortality may be regarded as acceptable and, overall, these very old patients tolerated emergency surgery quite well.

Aged↗

PubMed2003

Optoelectronic measures in the analysis of running target shooting.

In this study, we examined the construct validity and practical significance of an optoelectronic shooting training system (Noptel ST 2000 Sport) for the technical analysis of running target shooting. A total of 37 male shooters of three different skill levels participated in the study. Principal component analysis revealed four common factors of 16 variables describing the aiming trajectory of the rifle barrel: (i) Holding area, (ii) Accuracy of aiming, (iii) Cleanness of triggering and (iv) Time on target. These factors were suggested to describe the essential components of running target shooting. According to the discriminant analysis, the shooters of various skill levels seemed to discriminate successfully into three groups when the aiming trajectory data were analysed. Finally, the aiming trajectory variables represented a 43% of the total variance in the shooting score. In summary, the present data indicated that the optoelectronic shooting training system had practical significance and supported the technical analysis of rifle barrel movement in running target shooting. A sub-set of variables, which reflect the essential information of running target shooting performance, were outlined for training and coaching purposes.

Adult↗

PubMed2001

Effects of 12-week shooting training and mode of feedback on shooting scores among novice shooters.

The mode of feedback has been shown to have an effect on motor skill learning. This study investigated effects of an intensive 12-week shooting training period, and of the mode of feedback on scores in standing and running target shooting among 30 novices with limited shooting experience. They were divided into one control (no training) and three training groups. One out of the three training groups received only KR (knowledge of results) while the two other groups received KR+KP (knowledge of performance). One of the KR+KP groups received additional visual feedback (FB-II group), which included videos, graphic and written materials about kinematic and kinetic characteristics of their respective shooting techniques compared to performance of international level shooters. Each training group improved their scores in the running target shooting. There were no significant differences between the three training groups in improvements of sum scores (performance outcome). The current study showed that among novice shooters both KR alone and KR+KP improved running target shooting outcome, and that KR and KP together did not lead to a significantly better shooting performance than KR alone.

Adult↗

PubMed2000

Aiming routines and their electrocortical concomitants among competitive rifle shooters.

The present study focused on an examination of competitive shooters' aiming process during a rifle shooting task. The barrel movements of the rifle, as detected by a laser system during the last 1000-ms time period preceding the triggering, were recorded from six elite and six pre-elite shooters. Electrocortical slow potentials (SPs) from frontal (Fz), centro-lateral (C3, C4), and occipital (Oz) brain areas were recorded to get an additional insight into the underlying covert processing. The results suggested that the elite shooters did not pull the trigger until they reached a sustained rifle position. In the pre-elite shooters the rifle appeared to be in a less stable position, and their strategy was to take advantage of the first appropriate moment of steadiness without a sustained rifle position so they could pull the trigger. The observed pre-trigger readiness potential (RP) shifts at Fz and Oz were more positive among the elite shooters relative to the pre-elite shooters, reflecting their more pronounced covert effort, rather than increasing preparedness for the trigger pull. The present study lends support for the view that a successful aiming strategy is mainly based on sustained rifle balancing. With regards to the brain slow potentials, it can be concluded that the RP shift does not specifically reflect the preparation for the trigger pull.

Action Potentials↗

PubMed1998

Preparatory heart rate patterns in competitive rifle shooting.

In this study, we examined the relationship between preparatory heart rate patterns and competitive shooting performance. Cardiac activity was recorded from six elite and six non-elite male rifle shooters during the 6 s before the trigger pull. The assessment of shooting performance was based on three variables: shooting score, rifle stability and electromyographic (EMG) activity in the upper body. Each shooter showed a decrease in the pre-trigger heart rate that did not covary with the shooting scores. The magnitude of this change was greater for the non-elite shooters compared to the elite shooters, suggesting that the heart rate patterns reflected skill-related aspects of preparatory performance. The analyses of rifle-hold performance (rifle stability and EMG) suggested that the observed heart rate changes were associated with a shooter's attempts to achieve a rigid rifle position, but depend on his skill level. Interpretation of preparatory heart rate patterns in competitive rifle shooting should not be based solely on the attentional focusing aspect, but should also take into account the effects of a shooter's psychomotor regulation.

Adult↗

PubMed1998

Rifle-balancing in precision shooting: behavioral aspects and psychophysiological implication.

This study investigated sharpshooters' strategies to control their rifle stability during the aiming period. Six elite and six pre-elite shooters completed a simulated realistic shooting task (laser rifle), and their performance was evaluated from behavioral and psychophysiological perspectives. The analysis of the rifle's barrel movement, indexing the shooter's behavioral performance, supported the view that rifle-balancing is an essential determinant of superior shooting performance. The psychophysiological data, i.e. the brain slow potentials, suggested that the shooters applied different rifle-hold strategies; the elite shooters concentrated primarily on achieving a stable rifle position using psychomotor regulation, whereas the pre-elite shooters were more reliant on the visual-spatial processing. The present study has implications for the understanding of psychological aspects in competitive precision shooting, as well as for the evaluation of the functional significance of the electrocortical slow potentials in shooting-like closed-skill sports.

Action Potentials↗

PubMed1996

Postural stability and skilled performance--a study on top-level and naive rifle shooters.

Posture control during aiming over a period of 7.5 s preceding the shot was studied among national top-level rifle shooters as well as among national level shooters and amateurs familiar with rifle shooting. Movement of the center of forces (COF) was analyzed in terms of the speed and amplitude of the movement. These calculations were carried out in 1.5 s windows, the first window beginning 7.5 s and ending at 6.0 s prior the shot. The last window ended at the trigger pull. Posture control data differentiated the studied groups according to their level in competitive shooting. The male top-level shooters could stabilize their posture significantly better than female top-level or male national level shooters, who were, in turn, much more stable than naive shooters. The experienced shooters were able to stabilize their posture even better during the last seconds preceding the shot, whereas in naive shooters there were no significant differences when the successive windows were compared with each other. When a comparison was made between the best and worst 20 shots of each subject, a significant difference in balance parameters was only observed among the naive shooters, who showed more pronounced movement of the COF in the less successful trials. Among the highly trained top-level shooters a miss in whole-body posture stabilization apparently seldom is a reason for a poor result.

Adult↗

PubMed1995

Brain slow potentials reflecting successful shooting performance.

Preparatory brain activity from frontal, centro-lateral, and occipital areas were recorded from top-level rifle shooters during shooting performance. The aim of the study was to examine the relation of brain slow potentials to qualitative (rifle holding) and quantitative (hit) aspects of superior shooting performance. For this purpose, a typology of slow potentials (SPs) was developed. The resulting SP types were used for unraveling the associations between the electrocortical activity and behavioral output. The main finding was that frontal positivity was associated with successful performance, but only if the central-right SP was more negative than the central-left one. This finding was explained as showing that, in the case of superior performance, a shooter is able to refrain from irrelevant motor activity (frontal positivity) and concomitantly concentrate on the visual-spatial processing (right-sided negativity). In all, the present experiment suggests that the SPs are consistently related to the covert aspects of shooting performance, which lack an overt manifestation. At the practical level, this means that the SPs provide a tool for accessing information concerning the optimal balance between visual-spatial targeting and motor activity which can make a valuable contribution to the understanding of superior shooting performance.

Action Potentials↗

PubMed1993

Brain slow waves preceding time-locked visuo-motor performance.

According to previous findings (Konttinen and Lyytinen, 1992), the slow brain negativity preceding the trigger pull in rifle-shooting tends to be decreased in successful shots among experienced marksmen, whereas no such pattern is found among inexperienced subjects. This effect was interpreted as resulting mainly from optimal arousal. However, another explanation is examined here. The aim of the experiment was to investigate slow electrocortical changes associated with motor regulation and visual aiming related to shooting performance. Four variations on a shooting task were used, in which the visual and motor components were contrasted. Motor activity related to gun stabilization was found to be associated with slow-wave positivity, whereas visual aiming was manifested as slow negativity. The results offer some basis for interpreting the individual slow brain wave patterns that predict shooting performance.

Action Potentials↗