Temel Tıp Bilimleri Bölümü Makale Koleksiyonu
https://hdl.handle.net/11655/511
2024-03-28T22:11:50ZDetermination Of Electromyography-Based Coordinated Fatigue Levels In Agonist And Antagonist Muscles Of The Thigh During Squat Press Exercise
https://hdl.handle.net/11655/24223
Determination Of Electromyography-Based Coordinated Fatigue Levels In Agonist And Antagonist Muscles Of The Thigh During Squat Press Exercise
Sozen, Hasan; Erdogan, Ercument; Ince, Alparslan; Soylu, A. Ruhi
Background. Simultaneous tiredness of two or more muscles around a joint can be defined as coordinated fatigue (co-fatigue) and might occur between agonist and antagonist muscles, and vary according to the level of sporting activity levels or gender. Objectives. The aim of this study was to determine the levels of coordinated fatigue in agonist and antagonist muscles during squat-press exercise. Methods. Twenty athletes and twenty sedentary subjects participated in the study. Surface electromyography signals of the rectus femoris, vastus lateralis obliquus, biceps femoris and semitendinosus muscles were recorded at the squat press position for 15 seconds during isometric contraction. Measurements were repeated five times and a 2-minute rest period was allowed between repetitions. After erroneous EMG elimination, movement artefacts were removed by using a 20 Hz high-pass Butterworth filter. Then, as a well-recognized fatigue index, the median frequency (MF) of each filtered middle part of the EMG signal (5 to 10 s. of contraction) was calculated, given that it is known that the MF decreases during isometric contractions. Finally, each MF-based co-fatigue index was calculated by dividing the mean RF and VLO median frequencies by the mean ST and BF median frequencies. The cumulative co-fatigue values of “male vs. female” and “sedentary vs. athlete” comparisons were performed by using a two-sided Student t-test with a Bonferroni correction. Results. There was a statistically significant (Bonferroni corrected p-value < 0.05) difference between the mean female (1.57 +/- 0.53) and the mean male (1.23 +/- 0.17) co-fatigue values, while there was no statistically significant difference between the mean co-fatigue values of sedentary (1.51 +/- 0.52) and athlete (1.29 +/- 0.27) subjects. Conclusion. The offered co-fatigue indices might be useful for other sports, physiotherapy and related areas if sufficient scientific proof is accumulated.
2019-01-01T00:00:00ZPre-Attentive Mismatch Response And Involuntary Attention Switching To A Deviance In An Earlier-Than-Usual Auditory Stimulus: An Erp Study
https://hdl.handle.net/11655/24224
Pre-Attentive Mismatch Response And Involuntary Attention Switching To A Deviance In An Earlier-Than-Usual Auditory Stimulus: An Erp Study
Ungan, Pekcan; Karsilar, Hakan; Yagcioglu, Suha
An acoustic stimulus elicits an electroencephalographic response called auditory event-related potential (ERP). When some members of a stream of standard auditory stimuli are replaced randomly by a deviant stimulus and this stream is presented to a subject who ignores the stimuli, two different ERPs to deviant and standard stimuli are recorded. If the ERP to standard stimuli is subtracted from the ERP to deviant stimuli, the difference potential (DP) waveform typically exhibits a series of negative-positive-negative deflections called mismatch negativity (MMN), P3a, and reorienting negativity (RON), which are associated with pre-attentive change detection, involuntary attention switching, and reorienting of attention, respectively. The aim of the present study was to investigate how these pre-attentive processes are affected if the change occurs earlier than its usual timing implied by isochronous standard stimuli. In the MMN paradigm employed, 15% of the standards were randomly replaced by deviant stimuli which differed either in their pitch, their earlier onset time, or in both. Event-related responses to these three deviants [timely pitch change (RTP), earlier onset (REO), earlier pitch change (REP)] and to standards (RS) were recorded from 10 reading subjects. To maintain identical stimulation histories for the responses subtracted from each other, “deviant-standard” difference potentials (DP) for “timely” and “early” pitch deviances were derived as follows: DPTP = RTP − RS and DPEP = REP − REO. Interestingly, the MMN components of the DPs to timely and early pitch deviances had similar amplitudes, indicating that regularity of stimulus timing does not provide any benefit for the pre-attentive auditory change detection mechanism. However, different scalp current density (SCD) dynamics of the MMN/P3a complexes, elicited by timely and early pitch deviances, suggested that an auditory change in a stimulus occurring earlier-than-usual initiates a faster and more effective call-for-attention and causes stronger attention switching than a timely change. SCD results also indicated that the temporal, frontal, and parietal MMN components are simultaneously present rather than emerging sequentially in time, supporting the MMN models based on parallel deviance processing in the respective cortices. Similarity of the RONs to timely and early pitch deviances indicated that reorienting of attention is of the same strength in two cases.
2019-01-01T00:00:00ZWhat Is The Optimal Frequency For Ankle Muscles During Whole-Body Vibration Exercises?
https://hdl.handle.net/11655/24225
What Is The Optimal Frequency For Ankle Muscles During Whole-Body Vibration Exercises?
Tor, Omer Burak; Ecemis, Zeynep Berfu; Cobanoglu, Gamze; Suner-Keklik, Sinem; Kafa, Nihan; Soylu, Ruhi; Guzel, Nevin A.
Usage of the whole-body vibration (WBV) is effective in preventing the ankle injuries caused by increasing neuromuscular activity. The aim of this study was to investigate effective frequencies for neuromuscular activity of ankle muscles. A single-group, repeated-measures study design was used. Twenty-three healthy subjects (age 23.91 +/- 3.07, BMI 22.66 +/- 3.39) participated in this study. This study investigated the effects of WBV on the EMG responses of the Tibialis Anterior (TA), Peroneus Longus (PL), Gastrocnemius Medial (GM) and Lateral heads (GL). The muscle activity was measured with an 8-channel EMG Noraxon MiniDTS system (Noraxon, USA, Inc, Scottsdale, AZ) during 0, 20, 40 and 60 Hz of vibration. The Physio Plate (R) vibration platform (Physio Plate (R), Domino S.R.L, San Vendemiano, Italy) was used to deliver mechanical vibration. Compared with no vibration condition; EMG activity of all ankle muscles were significantly increased from at 60 Hz (123 % in TA, 64 % in PL, 53 % in GM, 77 % in GL) (p<0.01). At 40 Hz of vibration frequency, EMG responses of GM and GL was significantly increased (27 % and 53%, respectively) (p<0.01). Only GL was significantly increased of 33 % at 20 Hz (p<0.01). It could be concluded that using higher frequencies at whole-body vibration exercises are more effective than lower frequencies on ankle muscles' EMG activities. During squat exercises on the WBV platform, higher frequencies should be used to increase ankle muscle activation.
2019-01-01T00:00:00ZThe Morphometry Of The Cavernous Part Of The Internal Carotid Artery
https://hdl.handle.net/11655/24222
The Morphometry Of The Cavernous Part Of The Internal Carotid Artery
Farimaz, M.; Celik, H. H.; Ergun, K. M.; Akgoz, A.; Urfali, B.
Background: In the study, the morphometric evaluation of internal carotid artery (ICA) was performed in order to show the differences between the age groups and genders. Materials and methods: In the study, descriptive measurements of intercarotid distance on the computed tomography of 173 (88 male [M], 85 female [F]) patients and the intercavernous distance on magnetic resonance images (MRIs) of 49 (19 M, 30 F) individuals were reviewed. Results: Intercarotid distance was found to be close to the border of statistical significance and for results of the comparative measurements that were performed in the study; no significant sex-associated difference was observed for the distance between the gender and midpoint of the sella turcica and medial margin of the right ICA. Compared to gender, the distance between the base of the sella turcica and the base of the left ICA is found to be closed to of statistical significance. A statistically significant difference was obtained for the distance between the midpoint of sella turcica and medial margin of the left ICA and for the distance between the base of the sella turcica and the base of right ICA. Although it is observed that there is a weak correlation between the age and the distance between midpoint of the sella turcica and medial margin of the right ICA, statistically there is a significant difference between them. Conclusions: Obtained results, planning of surgical interventions are supportive and guiding in terms of prevention of damage of to ICA in three dimensional thinking and operations.
2019-01-01T00:00:00Z