• The Journal of Korean Physical Therapy
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• 제22권5호
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• pp.77-82
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• 2010

Purpose: The purpose of this study was to compare the pathway of COP and plantar foot pressure and to determine the correlation between plantar regions during the ascending and descending of a ramp. Methods: Fifteen healthy adults who had no musculoskeletal problems participated in our study. They were asked to walk on a level surface and on an ascending and descending ramp in their bare feet. Pathway of COP and plantar foot pressures were recorded using the Matscan system (Tekscan, Boston, USA). For pressure measurements, the plantar foot surface was divided into seven regions: two toe regions, three forefoot regions, a midfoot region, and a heel region. To determine whether there was a statistically significant difference between pathway of COP and plantar foot pressures during walking, we used repeated measuremes ANOVA. Results: In comparison to results for a level walking, pathway of COP while ascending a ramp had a tendency to be shifted medially in the forefoot and became longer till the big toe. Pathway of COP while descending a ramp also was shifted medially, but ended in the forefoot. Plantar foot pressure of the second and third metatarsal head and the fourth and fifth metatarsal heads was significantly decreased while descending the ramp. Conclusion: These results indicated that plantar foot pressure is changed while ascending and descending a ramp and demonstrated that ramp walking can affect the structure and function of the foot. Therefore, gait environment is associated with significant changes in foot characteristics, which contribute to altered plantar loading patterns during gait.

• 한국콘텐츠학회논문지
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• 제10권8호
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• pp.257-265
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• 2010

본 연구는 내림 경사로를 내려오는 동안 경사로의 기울기 변화가 보행 시 족저 영역별 최고 압력과 입각기 동안 압력중심이동경로를 분석하고자 실시하였다. 보행에 문제가 없는 열다섯 명의 건강한 젊은 성인이 이 연구에 참여하였으며 각각 평지, 내림경사 $5^{\circ}$, $10^{\circ}$, $15^{\circ}$의 경사로를 내려오는 동안 입각기 발의 족저 최고 족저압과 압력중심이동경로를 측정하였다. 측정장비는 Tekscan사의 Footmat system을 이용하였으며, 대상자의 발을 일곱 개의 영역(두 개의 발가락 영역, 세 개의 전족부 영역, 한 개의 중족부와 후족부영역)으로 나누어 자료를 수집하였다. 내림경사로의 기울기에 따른 최고 족저압의 차이를 알아보기 위해 반복측정분산분석을 이용하였고 압력중심이동경로는 육안적 관찰을 통해 알아보았다. 본 연구를 통해 내림경사로의 기울기가 커질수록 입각기 동안 최고 족저압은 엄지발가락영역에서 유의하게 증가하였고 세개의 전족부 영역에서는 유의하게 감소하였다. 그리고 압력중심이동경로는 내림경사로의 기울기가 커질수록 전족부에서 압력 중심이 내측으로 이동하였고 엄지발가락까지 길어지는 경향을 볼 수 있었다. 따라서 내림경사로의 기울기가 $-5^{\circ}$에서부터 일부 족저영역의 압력분포가 유의하게 달라지며 이는 내림경사로의 기울기가 발의 구조와 기능에 영향을 미친다는 것을 알 수 있었다.

• 한국전문물리치료학회지
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• 제13권2호
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• pp.16-25
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• 2006

The aim of this study was to investigate the kinematics of young adults during descent ramp climbing at different inclinations. Twenty-three subjects descended four steps at four different inclinations (level, $-8^{\circ}$, $-16^{\circ}$, $-24^{\circ}$). The 3-D kinematics were measured by a camera-based Falcon System. The data were analyzed using one-way ANOVA and the Student-Newman-Keuls test. The kinematics of descent ramp walking could be clearly distinguished from the kinematics of level walking. On a sagittal plane, the ankle joint was more plantar flexed at initial contact with $-16^{\circ}/-24^{\circ}$ inclination, was decreased in the toe off position with all inclinations (p<.001),and was decreased at maximum plantar flexion during the swing phase (p<.001). The knee joint was more flexed at initial contact with the $-24^{\circ}$ inclination (p<.001), was more flexed in the toe off position with all inclinations (p<.001), and was more flexed at minimum flexion during stance phase and at maximum flexion during swing phase with $-16^{\circ}$, $-24^{\circ}$ inclination (p<.001). The hip joint was more flexed in the toe off position with $-16^{\circ}$, $-24^{\circ}$ inclination and was deceased at maximum extension during stance phase with $-16^{\circ}$, $-24^{\circ}$ inclination (p<.05). In the frontal plane, the ankle joint was more everted at maximum eversion during stance phase with $-16^{\circ}/-24^{\circ}$ inclination (p<.01) and was decreased at maximum inversion during swing phase with $-16^{\circ}$, $-24^{\circ}$ inclination (p<.01). The knee joint was more increased at maximum varus during stance phase with $-16^{\circ}/-24^{\circ}$ inclination (p<.001). The hip joint was deceased at maximum adduction during stance phase with $-24^{\circ}$ inclination (p<.05). In a horizontal plane, only the knee joint was increased at maximum internal rotation during stance phase with $-24^{\circ}$ inclination (p<.05). In descent ramp walking, the different gait patterns occurred at an inclination of over $16^{\circ}$ on the descending ramp in the sagittal and frontal planes. These results suggest that there is a certain inclination angle or angular range where subjects do switch between level walking and descent ramp walking gait patterns.

• The Journal of Korean Physical Therapy
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• 제18권1호
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• pp.95-106
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• 2006

Purpose: The aim of this study was to investigate the kinematics of young adults during ramp climbing at different inclinations. Methods: Twenty-three subjects ascended and descended four steps at four different inclinations(level, $8^{\circ},\;16^{\circ},\;24^{\circ}$). Temporal-spatial parameters were measured by GaitRite system(standard mat). Groups difference was analysed with on-way ANOVA and Student-Newman-Keuls test. Results: The different kinematics of ramp ascent and descent were analysed and compared to level walking patterns. In ascending ramps, step length and stride length decreased with $24^{\circ}$ inclination (p<.000). Stance duration increased with $24^{\circ}$, but swing duration decreased with $24^{\circ}$ inclination (p<.000). Step time and velocity decreased with $16^{\circ}C,\;24^{\circ}$ inclination (p<.000). Cadence decreased with all inclination($8^{\circ},\;16^{\circ},\;24^{\circ}$)(p<.000). In descending ramps, step length and stride length, velocity decreased with all inclination($8^{\circ},\;16^{\circ},\;-24^{\circ}$)(p<.000). Stance duration increased with all inclination($8^{\circ},\;-16^{\circ},\;-24^{\circ}$) and swing duration decreased with all inclination($-8^{\circ},\;-16^{\circ},\;-24^{\circ}$)(p<.000). But Step time was not differentiated with different inclinations. Cadence decreased with only. $8^{\circ}$ inclination(p<.05). Conclusion: These results suggest that there is a certain inclination angle or angular range where subjects do switch between level walking and ramp walking gait pattern. This shows their motor control strategy between level and ramp walking. Further studies are necessary to confirm and detect the ascent and descent ramp gait patterns.

• PNF and Movement
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• 제17권1호
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• pp.137-144
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• 2019

Purpose: This study examined the effects of the abdominal drawing-in maneuver (ADIM) on muscle activity in the trunk and legs while subjects walk on a ramp. Methods: The subjects were healthy adult males (n=15) and females (n=8) in their twenties. The subjects were asked to maintain the ADIM contraction for 15 minutes using a pressure biofeedback unit. Their muscle activity was then measured while ascending or descending the ramp with or without the ADIM contraction maintained. Activity in the sternocleidomastoid, splenius capitis, rectus abdominis, external oblique abdominal, transversus abdominis, erector spinae, vastus medialis, and vastus lateralis muscles was measured using surface electromyography (TM DTS, Noraxon, USA). A paired t-test was conducted using SPSS 18.0 (IBM) for statistical data processing. Results: Maintaining the ADIM contraction during ascension led to a significant increase (p<0.05) in muscle activity for the rectus abdominis, transversus abdominis, vastus medialis, and vastus lateralis, but a significant decrease (p<0.05) in muscle activity for the erector spinae, when compared to the same activity without the ADIM maintained. Furthermore, maintaining the ADIM contraction during descent led to a significant increase (p<0.05) in muscle activity for the rectus abdominis, external abdominal oblique, transversus abdominis, vastus medialis, and vastus lateralis, but a significant decrease (p<0.05) in muscle activity for the erector spinae, when compared to the same activity without the ADIM maintained. Conclusion: As a result of this study, it maintains the ADIM and reduces lumbar muscle activity at the waist and increases muscle activity in the legs when walking on a ramp. Therefore, maintaining the ADIM contraction during ramp walking is recommended as training to improve the function of patients' muscular skeleton.

• The Korean Journal of Physiology and Pharmacology
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• 제9권2호
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• pp.95-101
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• 2005

In the heart, $Na^{+}-Ca^{2+}$ exchange (NCX) is the major $Ca^{2+}$ extrusion mechanism. NCX has been considered as a relaxation mechanism, as it reduces global $[Ca^{2+}]_i$ raised during activation. However, if NCX locates in the close proximity to the ryanodine receptor, then NCX would curtail $Ca^{2+}$ before its diffusion to global $Ca^{2+}_i$ This will result in a global $[Ca^{2+}]_i$ decrease especially during its ascending phase rather than descending phase. Therefore, NCX would decrease the myocardial contractility rather than inducing relaxation in the heart. This possibility was examined in this study by comparing NCX-induced extrusion of $Ca^{2+}$ after its release from SR in the presence and absence of global $Ca^{2+}_i$ transient in the isolated single rat ventricular myocytes by using patch-clamp technique in a whole-cell configuration. Global $Ca^{2+}_i$ transient was controlled by an internal dialysis with different concentrations of BAPTA added in the pipette. During stimulation with a ramp pulse from +100 mV to -100 mV for 200 ms, global $Ca^{2+}_i$ transient was suppressed only mildly, and completely at 1 mmol/L, and 10 mmol/L BAPTA, respectively. In these situations, ryanodine-sensitive inward NCX current was compared using $100{\mu}mol/L$ ryanodine, $Na^+$ depletion, 5 mmol/L $NaCl_2$ and $1{\mu}mol/L$ nifedipine. Surprisingly, the result showed that the ryanodine-sensitive inward NCX current was well preserved after 10 mmol/L BAPTA to 91 % of that obtained after 1 mmol/L BAPTA. From this result, it is concluded that most of the NCX-induced $Ca^{2+}$ extrusion occurs before the $Ca^{2+}$ diffuses to global $Ca^{2+})i$ in the rat ventricular myocyte.