• 한국자동차공학회논문집
• /
• 제22권1호
• /
• pp.126-134
• /
• 2014

This study investigates the structural strength analysis due to rib thickness of lower arm. At structural analysis, model 1 has the most deformation by comparing three models. As most equivalent stress is shown at the part connected with wheel knuckle, the strength becomes weaker in cases of three models. At fatigue analysis, model 1 becomes most unstabilized among three models. Model 3 has most fatigue life and the next model is model 2. The range of maximum harmonic response frequencies becomes 140 to 175Hz in cases of three models. Because the critical frequency at model 3 becomes highest among three models but the stress exceeds yield stress, model 3 becomes most unstabilized at vibration durability. As models 1 and 2 has less than yield stress, these models become stabilized. Model 2 becomes most favorable by comparing three models at structural, fatigue and vibration analyses. This study result can be effectively utilized with the design of lower arm by investigating prevention against damage and its strength durability.

• 한국CDE학회논문집
• /
• 제18권5호
• /
• pp.359-366
• /
• 2013

In the lower arm design process, a tolerance optimization of the variance of design variables should be preceded before manufacturing process, since it is very cost-effective compared to a strict management of tolerance of products. In this study, a design of experiment (DOE) based on response surface model (RSM) was carried out to find optimized design variables of the lower arm, which can meet a given requirement of probability constraint for the process capability index (Cpk) of the weight and maximum stress. Then, the design space was explored by using the central composite design method, in which the 2nd order Taylor expansion was applied to predict a standard deviation of the responses. The optimal solutions satisfying the probability constraint of the Cpk were found by considering both of the mean value and the standard deviation of the design variables.

• PNF and Movement
• /
• 제12권1호
• /
• pp.7-12
• /
• 2014

Purpose: The purpose of this study is to analyze the effect of the arm extension pattern of proprioceptive exercise program on the muscle activity of the opposite lower extremity. Methods: In this study, electromyogram MP150(Biopac system, USA) was applied to 20 healthy male subjects. Arm extension-adduction-internal rotation pattern was applied within initial, mid and end range in sling position and supine position for measurement. And the effect on the activity of rectus femoris and tibialis anterior muscle of the opposite lower extremity was compared and analyzed. Results: The results of this study were summarized as follows: First, there was a statistically significant difference of the activity of the tibialis anterior muscle within the Initial range in sling position and supine position(P<0.05). Second, there was a statistically significant difference of the activity of the tibialis anterior muscle within the end range in sling position and supine position(P<0.05). Conclusion: Rectus femoris and tibialis anterior muscles shows the higher activity in the supine position than in the sling position. Therefore, the supine position is more appropriate than the sling position to make irradiation on lower extremity muscle with the extension pattern.

• Journal of Mechanical Science and Technology
• /
• 제19권spc1호
• /
• pp.444-451
• /
• 2005

The analysis of human arm motion during steering maneuver is carried out for investigation of man-machine interface of driver and steering system Each arm is modeled as interconnection of upper arm, lower arm, and hand by rotational joints that can properly represents permissible joint motion, and both arms are connected to a steering wheel through spring and damper at the contact points. The joint motion law during steering motion is determined through the measurement of each arm movement, and subsequent inverse kinematic analysis. Combining the joint motion law and inverse dynamic analysis, joint stiffness of arm is estimated. Arm dynamic analysis model for steering maneuver is setup, and is validated through the comparison with experimentally measured data, which shows relatively good agreement. To demonstrate the usefulness of the arm model, it is applied to study the effect of steering column angle on the steering motion.

• 감성과학
• /
• 제6권1호
• /
• pp.27-32
• /
• 2003

본 연구에서는 스포츠웨어용 나일론 직물 소리가 심한 소음으로 인해 불쾌감을 주므로 이를 감소시키기 위한 방안으로, 5개의 나일론 직물소리를 녹음하여 이를 피험자에게 들려주면서 EMG와 주관적 감각을 측정함으로써, 직물소음이 근전도와 주관적 감각에 미치는 영향을 고찰하였다. 근전도는 상완이두근과 전완근에서 측정하였고, 주관적 평가는 자유식 크기평가법(Free Modulus Magnitude Estimation)을 이용하였다. 직물 소리에 대한 상완이두근의 근전도 값은 전완근의 근전도값보다 컸으며, 소리자극 유무시의 차이값도 상완이두근에서 크게 나타났다. 직물의 소리가 부드럽고 유쾌할수록 근전도값은 무자극시보다 감소하는 경향을 보였으나, 직물의 소리가 시끄럽고 날카로울수록 근전도값은 무자극시보다 증가하였다. 직물의 소리는 상완이두근의 근전도 값에 영향을 미쳐, 직물 소음의 크기, 날카로움 등과 정적인 관계를 보이는 것을 볼 수 있었다. 직물소리의 물리적 특성과 근전도로부터 나일론 직물 소리에 대한 감각ㆍ감성 예측식에서는 높은 예측력을 보였다. 맑고, 거칠고, 높은 소리감각을 제외한 예측식에서 소리특성 외에 생리신호인 근전도 가 포함되어 직물소리 감성을 예측하는 의미있는 파라미터임을 알 수 있었다.

• Annals of Clinical Neurophysiology
• /
• 제7권2호
• /
• pp.83-87
• /
• 2005

Background: The study of the medial antebrachial cutaneous nerve (MABCN) is an underused electrodiagnostic tool. But its use is often crucial for assessing mild lower brachial plexus or MABCN lesions, and sometimes for differentiating an ulnar mononeuropathy from a lower brachial plexopathy. This study was designed to know the difference of amplitude and velocity in a stimulation method (orthodromic vs antidromic), side of an arm and sex according by age. Method: MABCN conduction studies were performed orthodromically and antidromically in 90 subjects (42 women and 48 men, ranging from 22 to 79 years of age). We divided subjects into three groups by age (group 1: 20-39 years, group 2: 40-59 years, group 3: 60-79 years). The mean sensory nerve action potential amplitudes and sensory nerve conduction velocities in each group was compared by stimulation method, side of an arm and sex. Result: The amplitudes and velocities made a significant difference between orthodromic and antidromic method in all age groups. At comparison in amplitude and velocity by side of an arm, only amplitude was significantly higher in right arm than left by any stimulation method. The amplitudes and velocities were of no statistically differences in sex except amplitude checked orthodromically in right arm. Conclusion: This study suggests that there is the differences in conduction study of MABCN by stimulation method and side of an arm.

• 국제물리치료학회지
• /
• 제10권3호
• /
• pp.1849-1855
• /
• 2019

Background: Stroke patients require arm movement exercising for various stimulations in standing position for various stimulations rather than in a sitting position because they require integrated skillful movements, such as stretching, holding, and controlling. Objective: This study was conducted to provide foundational clinical data about lower limb global synkinesis in stroke patients using arm movements in a standing position. Design: Randomized controlled trial. Methods: The subjects were divided into a control group (n = 10) and an experimental group (n = 10), and a pre-test was conducted to evaluate leg global synkinesis (GS) and balance. Intervention method is stretching an arm to hold a ball, repeating supination and pronation of the hand only while maintaining the arm extended as much as possible, repeating shoulder abduction and adduction while holding the pegboard. This was followed by a three-week intervention during which re-measurement was conducted in the same way as was done for the pre-test. Results: The control group showed a significant difference in GS and balance during plantar flexion (p<.05), and the experimental group showed a significant difference in GS and balance during all movements (p<.05, p<.01, respectively). There was a significant difference in GS and balance between the two groups during dorsiflexion (p<.05, p<.01, respectively). Conclusion: The findings demonstrate that human arm movements in a standing position can reduce GS in the affected limb, and balance can be improved by stimulating the surrounding tissues of the affected limb and changing them positively.

• 대한물리의학회지
• /
• 제15권3호
• /
• pp.11-20
• /
• 2020

PURPOSE: Excessive activity of the upper trapezius (UT) muscle contributes to a rounded shoulder posture (RSP) through abnormal rotation of the scapula that weakens the lower trapezius (LT) and serratus anterior (SA) muscles. This study compared the effects of two arm-lifting exercises with and without the use of a Thera-band on the activities of LT, SA, and UT muscles, and the LT/UT and SA/UT activity ratio in subjects with a rounded shoulder posture. METHODS: Sixteen subjects with RSP participated in this study. All subjects performed arm-lifting (AL), diagonal arm-lifting (DAL), arm lifting with isometric adduction (ALIA), and diagonal arm-lifting with isometric adduction (DALIA) exercises. The surface electromyography data, LT, SA, UT, and the LT/UT and SA/UT activity ratios were measured. A paired t-test was used to compare the differences between two arm-lifting exercises and two arm lifting with isometric adduction exercises. RESULTS: In ALIA and DALIA exercises, the UT muscle activity decreased significantly, whereas the LT/UT, SA/UT activity ratio increased significantly. The activity of SA muscle increased significantly more with DALIA than that with DAL. CONCLUSION: Arm-lifting exercises using a Thera-band can be implemented as an effective way to reduce the UT overactivity and increase the SA activity and LT/UT, SA/UT activity ratio in subjects with RSP.

• 대한한방체열의학회지
• /
• 제2권1호
• /
• pp.43-48
• /
• 2003

Obesity is excess body weight, defined as a body mass index (BMI) over 30 kg/m2. or 20% over than relative body weight (RBW). We can consider the surface temperature of obesity patients is related with fat distribution and differs from that of non obesity people. The temperature is measured by using Digital Infrared Thermal Imaging(DITI). DITI was taken on 109 people without any specific disease. Among those subjects, obesity group is 77 and non obesity is 32. We measured the surface temperature by describing regular square on the upper arm, lower arm, palm, upper leg, lower leg, foot, upper abdomen and lower abdomen. The temperature of upper leg, upper abdomen and lower abdomen was low (p<0.001) and that of palm and foot was high (p<0.05) in obesity group. The temperature and the difference of lower arm to palm and lower leg to foot correlated with RBW. These results suggest the surface temperature in obesity group differ remarkably from that in non obesity group.

• 대한기계학회논문집A
• /
• 제27권7호
• /
• pp.1243-1250
• /
• 2003

In the present study, hot forging process for a lower arm connector of an automobile was investigated. An FEM code, DEFORM-3D, was used to analyze the process and the process parameters, such as temperature, strain and strain rate, were obtained. The microstructure of the connector was predicted by applying the Sellars and Yada microstructure evolution models to the process parameters. The method of microstructure prediction used in the present study seems to be effective for the quality assurance of a forged automotive product.