• Korean Journal of Applied Biomechanics
• /
• v.24 no.1
• /
• pp.43-50
• /
• 2014

The purpose of this study was to analyze of the GRF (ground reaction force) parameters according to the change of positions and weights of bag during downward stairs between dominant and non-dominant in upper & lower limbs. To perform this study, participants were selected 9 healthy women (age: $21.40{\pm}0.94yrs$, height: $166.50{\pm}2.68cm$, body mass: $57.00{\pm}3.61kg$, BMI: $20.53{\pm}1.03kg/m^2$), divided into 2 carrying bag positions (dominant arm/R, non-dominant arm/L) and walked with 3 type of bag weights (0, 3, 5 kg) respectively. One force-plate was used to collect GRF (AMTI OR6-7) data at a sample rate of 1000 Hz. The variables analyzed were consisted of the medial-lateral GRF (Fx), anterior-posterior GRF (Fy), vertical GRF (Fz), impact loading rate and center of pressure (COPx, COPy, COP area, COPy posterior peak time) during downward stairs. 1) The Fx, Fy, Fz, COPx, and COP area of GRF were not statistically significant between dominant leg and non-dominant leg, but non-dominant leg, that is, showed the higher COPy, and showed higher impact loading rate than that dominant leg during downward stairs. 2) In bag wearing to non-dominant arm, Fx, Fz, COPx, COPy, impact loading rate and COP area showed increase tendency according to increase of bag weights. Also, against bag wearing to dominant arm, non-dominant showed different mechanism according to increase of bag weights. The Ground Reaction Force parameters showed different characteristics according to the positions and weights of bag during downward stairs between dominant and non-dominant arm.

• Clinics in Shoulder and Elbow
• /
• v.1 no.2
• /
• pp.221-229
• /
• 1998

We measured, with manual goniometer, the active and passive arc of motion of the shoulder in 31 healthy male subjects who were right-hand dominant and who ranged in age from twenty to thirty-one years. Among ten directions through the four motion plane, the range of motion on the dominant side were significantly smaller than those on the non-dominant side in the motion of six directions. We also measured the motion fraction of the glenohumeral and scapulothoracic movement using fluoroscope in 30-degree intervals of arm elevation in the scapular plane. The ratio of glenohumeral to scapulothoracic movement(θGH/θST) was 1.6 for the full range of motion in scapular plane. At the lower angles of abduction, scapulothoracic movement was slight compared with glenohumeral movement. The motion fraction of scapulothoracic joint was increased from 60-degree to 150 degree of arm angle especially between 120 to 150 degree. During arm elevation, scapula was also extended from 42 degrees to 20 degrees tilting as well as internal rotation. The measuring technique of glenohumeral to scapulothoracic movement(θGH/θST) with fluoroscopy could be applied to the simple radiographic measurement at the out-patient clinic in order to identify the pathology and recovery of shoulder motion after treatment.

• International Journal of Internet, Broadcasting and Communication
• /
• v.13 no.2
• /
• pp.260-266
• /
• 2021

Handwriting using the dominant and nondominant arms was analyzed in 52 young adults with the aid of a three-axial accelerometer. We measured a signal vector magnitude (SVM) and the percentage of the total signal vector magnitude (%TSVM) for the metacarpophalangeal joint (MCP), radial styloid process (RSP), and lateral epicondyle (LE) of both arms. The SVM for the MCP was lower in the dominant arm than the nondominant arm, whereas that for the RSP was higher. %TVSM was lower for the MCP than for the RSP and LE in the nondominant arm, but higher for the MCP than for the LE in the nondominant arm. These findings suggest that controlling the MCP will improve the quality of handwriting, including when using the nondominant arm.

• Journal of International Academy of Physical Therapy Research
• /
• v.2 no.1
• /
• pp.229-236
• /
• 2011

The purpose of this study was to comparatively analyze the active stability of shoulder joints according to the frequency of overhead motions, such as serving and spiking, engaged in by female professional volleyball athletes who play different positions, and to provide the results as the basic data for developing exercise programs to prevent shoulder joint injuries. The subjects of this study were 50 Korean female professional volleyball players and positions were as follows: left and right attackers, centers, setters, and liberos. The external rotation and internal rotation muscle strength and muscle strength ratios of the dominant and non-dominant arms of all subjects were measured using Biodex. The results of this study are as follows: Frist, no significant differences were found in the internal and external rotation muscle strength of the dominant and non-dominant arms between positions. Second, for the shoulder joint muscle strength ratio of the dominant arm, by position, the setter showed significantly greater stability compared to the other positions. Third, for the shoulder joint muscle strength ratio of the non-dominant arm, by position, no significant difference in stability between positions was found. Fourth, it was found that the dominant arm had significantly greater instability of the shoulder joint than the non-dominant arm for attackers and centers, but no significant difference was found for setters and liberos. This study comparatively analyzed the muscle strength ratios of the external/internal rotations and dominant/non-dominant arms, which can determine the stability of the shoulder joints between female professional volleyball playing positions that engage in jumps and spikes using only the dominant hand and positions that do not.

• Journal of Korean Physical Therapy Science
• /
• v.16 no.4
• /
• pp.59-65
• /
• 2009

Background: Human body is formed of symmetric bilateral structures that are comprised of eye, upper arm, lower arm and etc. but, we are used only dominant components. The purpose of this study was to analysis length cognition ability in dominant eye & hand. Method: Total 180 persons (male 32, female 138) were participated in this study. They were tested with 'hole in the card' test for identification of dominant eye's side and the question for identification of dominant hand's side, then the length cognition ability was measured in right & left axillary level by describing 10cm line. Results: The results by independent t-test were as follows. In difference of length cognition ability in right axillary level between right dominant eyed group & left dominant eyed group, right dominant eyed group was superior to left dominant eyed group, but significant difference was not existed statistically(p>.05). In left axillary level, right dominant eyed group was superior to left dominant eyed group, but significant difference was not existed statistically(p>.05). In axillary level of dominant eye's side, non-crossed group was superior to crossed group, but significant difference was not existed statistically(p>.05). In axillary level of non-dominant eye's side, non-crossed group was superior to crossed group, but significant difference was not existed statistically(p>.05). Conclusion: These result can be applied to the learning of palpation & observation skill in physical therapy.

• Journal of Korean Physical Therapy Science
• /
• v.15 no.4
• /
• pp.11-17
• /
• 2008

Background: Human body is formed of symmetric bilateral structures that are comprised of eye, upper arm, lower arm and etc. but, we are used only dominant components. The purpose of this study was to analysis length cognition ability in dominant eye. Methods: Total 88 persons (male 18, female 70) were participated in this study. They were tested with ‘hole in the card’ test for identification of dominant eye's side, then the length cognition ability was measured in right & left axillary level by describing 10cm line. Results: The results by independent t-test were as follows. In difference of length cognition ability in right axillary level between right dominant eyed group & left dominant eyed group, right dominant eyed group was superior to left dominant eyed group, but significant difference was not existed statistically(p>.05). In left axillary level, right dominant eyed group was superior to left dominant eyed group, but significant difference was not existed statistically(p>.05). Conclusion: These result can be applied to the learning of palpation & observation skill in physical therapy, although this study was not identify a relation between dominant eye & dominant hand.

• Journal of Korean Orthopaedic Sports Medicine
• /
• v.1 no.1
• /
• pp.43-48
• /
• 2002

Purpose : We evaluated radiographic changes and clinical manifestations of the elbow joint to identify the effects of the throwing between dominant and non-dominant arms. Materials and Methods : A hundred and five little leaguer’s baseball player in 5 elementary school and 2 middle school were evaluated for clinical symptoms and radiographic changes about elbow joint. Mean age was 12 years old and average periods of exercise were 32 months. Elbow functions were evaluated using ASES standardized assessment form and radiographic changes of medial epicondyle were examinated for enlargement, separation of the apophyses, fragmentation and irregularity. Results : Thirty seven players (35$\%$) were complained pain with throwing and the average score was 4.8 using visual analog scale. There were no significant differences in range of motion except flexion angle, valgus angle, and strength between dominant arm and non-dominant arm. Valgus laxity was more prominent in dominant arm. Ulnohumeral tenderness, radiocapitellar tenderness and medial flexor origin tenderness were in 18, 6, and 17 cases respectively in dominant arm. Medial epicondyle was enlarged in dominant arm with 13.0 by 6.3 mm compared to non-dominant arm with 11.7 by 6.1 mm. Apophyseal separation was 0.8 mm in dominant arm and 0.5 mm in non-dominant arm. Fragmentation and irregularity were 14 (13$\%$) and 25 (24$\%$) cases respectively in dominant arm. Conclusion : In little league baseball player, it needs usage of ball and bat with appropriate weight, and careful conditioning programs through throwing exercise in order to avoid elbow injuries.

• Physical Therapy Korea
• /
• v.25 no.3
• /
• pp.51-59
• /
• 2018

Background: Despite muscle latency times and patterns were used as broad examination tools to diagnose disease and recovery, previous studies have not compared the dominant arm to the non-dominant arm in muscle latency time and muscle recruitment patterns during reaching and reach-to-grasp movements. Objects: The present study aimed to investigate dominant and non-dominant hand differences in muscle latency time and recruitment pattern during reaching and reach-to-grasp movements. In addition, by manipulating the speed of movement, we examined the effect of movement speed on neuromuscular control of both right and left hands. Methods: A total of 28 right-handed (measured by Edinburgh Handedness Inventory) healthy subjects were recruited. We recorded surface electromyography muscle latency time and muscle recruitment patterns of four upper extremity muscles (i.e., anterior deltoid, triceps brachii, flexor digitorum superficialis, and extensor digitorum) from each left and right arm. Mixed-effect linear regression was used to detect differences between hands, reaching and reach-to-grasp, and the fast and preferred speed conditions. Results: There were no significant differences in muscle latency time between dominant and non-dominant hands or reaching and reach-to-grasp tasks (p>.05). However, there was a significantly longer muscle latency time in the preferred speed condition than the fast speed condition on both reaching and reach-to-grasp tasks (p<.05). Conclusion: These findings showed similar muscle latency time and muscle activation patterns with respect to movement speeds and tasks. Our findings hope to provide normative muscle physiology data for both right and left hands, thus aiding the understanding of the abnormal movements from patients and to develop appropriate rehabilitation strategies specific to dominant and non-dominant hands.

• Journal of International Academy of Physical Therapy Research
• /
• v.8 no.2
• /
• pp.1158-1162
• /
• 2017

The purpose of the study was to investigate the strength of sokinetic muscle by the position of a volleyball players. Analysis and comparison of shoulder dynamic stability will be conducted according to rotational movement of the shoulder during spiking and serving amongst the various positions. Fifty professional Korean female volleyball players (age: 20~30), all different positions - attacker (left and right), center, setter, and libero were The concentric peak torque, strength ration of the internal and external rotation of the shoulder girdle for both dominant and non-dominant arms. Firstly, there were significant differences found for the strength ratio between the setter and the other positions in the dominant arm. On a second note, there was a significant decrease in shoulder dynamic stabilization for both the attacker and center in the dominant arm. However, there were no significant differences for the setter or the libero. This study suggests that the isokinetic muscle strengths of the volleyball players are different from each other.

• Clinics in Shoulder and Elbow
• /
• v.26 no.2
• /
• pp.126-130
• /
• 2023

Background: Arm swing plays a role in gait by accommodating forward movement through trunk balance. This study evaluates the biomechanical characteristics of arm swing during gait. Methods: The study performed computational musculoskeletal modeling based on motion tracking in 15 participants without musculoskeletal or gait disorder. A three-dimensional (3D) motion tracking system using three Azure Kinect (Microsoft) modules was used to obtain information in the 3D location of shoulder and elbow joints. Computational modeling using AnyBody Modeling System was performed to calculate the joint moment and range of motion (ROM) during arm swing. Results: Mean ROM of the dominant elbow was 29.7°±10.2° and 14.2°±3.2° in flexion-extension and pronation-supination, respectively. Mean joint moment of the dominant elbow was 56.4±12.7 Nm, 25.6±5.2 Nm, and 19.8±4.6 Nm in flexion-extension, rotation, and abduction-adduction, respectively. Conclusions: The elbow bears the load created by gravity and muscle contracture in dynamic arm swing movement.