• The Journal of Korean Physical Therapy
• /
• v.26 no.6
• /
• pp.449-452
• /
• 2014

Purpose: The purpose of this study was to analyze the coordination between trunk flexion and lower limb extension contributing to vertical propulsion during sit-to-stand (STS) at different chair heights in the elderly. Methods: Ten elderly subjects were asked to stand up at their natural speed from different chair heights : (1) $90^{\circ}$ knee flexion; (2) $100^{\circ}$ knee flexion; (3) $110^{\circ}$ knee flexion; and (4) $120^{\circ}$ knee flexion. A standard chair without a backrest or armrests was used in this study. To remove inertial effects of upper limb movements, subjects were asked to stand up from a chair with their arms crossed at the chest. Mean of results of three trials were used in the analysis at different knee flexion angles. Distances moved by the shoulder for compensatory trunk movement was recorded by motion analysis and vertical force was recorded under foot using force plates. Distances moved by the shoulder and vertical ground reaction force measurements were analyzed using repeated ANOVA. Results: Distances moved by the shoulder significantly decreased with higher chair (p<0.05). Vertical forces were not significant difference on chair heights (p>0.05), but results of pairwise comparisons for vertical force revealed significant difference between $90^{\circ}$ knee flexion and $120^{\circ}$ knee flexion (p<0.05). Conclusion: Trunk movement is probably used as a compensatory mechanism at low chair heights to increase lift-off from sitting by the elderly.

• Physical Therapy Korea
• /
• v.26 no.4
• /
• pp.10-19
• /
• 2019

Background: In patients with lumbar spinal stenosis (LSS), lumbar flexion exercise (LFE) is considered a standard therapeutic exercise that widens the space between the spinal canal and intervertebral foramen. However, some researchers have reported that lumbar extension exercise (LEE) may improve lumbar pain and functional ability in patients with LSS. Although exercise intervention methods for patients with LSS have been widely applied in clinical settings, few studies have conducted comparative analysis of these exercise methods. Objects: This study aimed to compare the effects of LFE, LEE, and lumbar flexion combined with lumbar flexion-extension exercise (LFEE) on pain, range of motion (ROM), pelvic tilt angle, and functional gait ability in patients with LSS. Methods: A total of 30 patients with LSS, LFE (n1=10), LEE (n2=10), and LFEE (n3=10) were assigned to each of the three exercise groups. The numerical pain rating scale (NPRS), modified-modified schober test (MMST)-flexion, MMST-extension, pelvic tilt inclinometer, and 6-minute walking test (6MWT) were measured. Results: After the intervention, statistically significant differences were observed in the NPRS (p=.043), MMST-flexion (p<.001), MMST-extension (p<.001), and 6MWT (p=.005) between groups. According to the post hoc test, the NPRS was statistically significant difference between the LFEE and LEE groups (p=.034). The MMST-flexion was statistically significantly different between the LFE and LEE (p=.000), LFE and LFEE (p=.001), and LEE and LFEE (p=.001) groups. The MMST-extension was statistically significantly different between the LFE and LEE (p<.001), LFE and LFEE (p=.002), and LEE and LFEE (p=.008) groups. The 6MWT was statistically significantly different between the LFE and LFEE (p=.042) and the LEE and LFEE (p=.004) groups. Conclusion: This study suggested that LFEE was the most effective exercise for pain and functional gait ability in patients with LSS, LFE was the most effective exercise for lumbar flexion ROM, and LEE was the most effective exercise for lumbar extension ROM.

• Journal of Mechanical Science and Technology
• /
• v.15 no.7
• /
• pp.1013-1021
• /
• 2001

A series of rabbit common extensor tendon specimens of the humeral epicondyle were subjected to tensile tests under two displacement rates (100mm/min and 10mm/min) and different elbow flexion positions 45°, 90°and 135°. Biomechanical properties of ultimate tensile strength, failure strain, energy absorption and stiffness of the bone-tendon specimen were determined. Statistically significant differences were found in ultimate tensile strength, failure strain, energy absorption and stiffness of bone-tendon specimens as a consequence of different elbow flexion angles and displacement rates. The results indicated that the bone-tendon specimens at the 45°elbow flexion had the lowest ultimate tensile strength; this flexion angle also had the highest failure strain and the lowest stiffness compared to other elbow flexion positions. In comparing the data from two displacement rates, bone-tendon specimens had lower ultimate tensile strength at all flexion angles when tested at the 10mm/min displacement rate. These results indicate that creep damage occurred during the slow displacement rate. The major failure mode of bone-tendon specimens during tensile testing changed from 100% of midsubstance failure at the 90°and 135°elbow flexion to 40% of bone-tendon origin failure at 45°. We conclude that failure mechanics of the bone-tendon unit of the lateral epicondyle are substantially affected by loading direction and displacement rate.

• The Journal of Korean Physical Therapy
• /
• v.7 no.1
• /
• pp.43-49
• /
• 1995

The purpose of this study were to determine the effect of testing posture and elbow position on grip strength. Two hundred college students 100 males and 100 females aged 18 to 28 years, participated in the study. A Grip-Strength Dynamometer was used to measure the grip strength in two testing posture(sitting and standin) and four elbow position$(0^{\circ},\;45^{\circ},\;90^{\circ}\;and\;135^{\circ}\;flexion)$ correlations and t-test was used to determine any significant difference in grip strength between the testing posture and the elbow position. The results were as follows : 1. The grip strength was affected by testing pasture and flexion degree of elbow. 2. The grip strength was stronger in the standing than sitting in subjects 3. The grip strength decreased according to elbow flexion increase in subjects. 4. The higher grip strength gained in the standing with the elbow 0 flexion. 5. The grip strength by elbow flexion degree showed significant difference at sitting and standing posture. The grip strength was significant differenced by testing position at same elbow flexion degree.

• Korean Journal of Applied Biomechanics
• /
• v.16 no.3
• /
• pp.105-115
• /
• 2006

The purpose of this study is to elucidate the mechanical characteristics of lower extremity joint movements at different walking speeds in obese people and suggest the very suitable exercise for obese person's own body weight and basic data for clinical application leading to medical treatment of obesity. This experimental subjects are all males between the ages of 20 and 30, who are classified into two groups according to Body Mass Index(BMI): one group is 15 people with normal body weight and the other 15 obese people. Walking speed is analysed at 3 different speeds ($1.5^m/s$, $1.8^m/s$, $2.1^m/s$) which is increased by $0.3^m/s$ from the standard speed of $1.5^m/s$. We calculated joint moments of lower extremity during stance phase through video recording and platform force measurement.Two-way ANOVA(Analysis of Variance, Mix) is applied to get the difference of moments according to walking speeds between normal and obese groups. Pearson's Correlation Analysis is applied to look into correlation between walking speeds and joint moments in both groups. Significance level of each experiment is set as ${\alpha}=.05$. As walking speed increases maximum ankle plantar flexion moment in the stance phase is smaller in obese group than in normal group, which is suggestive of weak toe push-off during terminal stance in obese group, and the highest maximum ankle plantar flexion moment in obese group during the middle speed walking($1.8^m/s.$). Maximum ankle dorsal flexion moment in obese group is relatively higher than in normal group and this is regarded as a kind of compensatory mechanism to decrease the impact on ankle when heel contacts the floor. Maximum knee flexion and extension moments are both higher in normal group with an increase tendency proportional to walking speed and maximum hip flexion and extension moments higher in obese group. In summary, maximum ankle plantar flexion moment between groups(p<.025), maximum knee moment not in flexion but in extension(p<.001) within each group according to increasing walking speed, and maximum hip flexion and extension moment(p<.001 and p<.004, respectively according to increasing walking speed are statistically significant but knee and hip moments between groups are not. Pearson correlation are different: high correlation coefficients in maximum knee flexion and extension moments, in maximum hip extension moment but not hip flexion, and in maximum ankle dorsal flexion moment but not ankle plantar flexion, in each group. We suspect that equilibrium imbalance develops when the subject increases walking speed and the time is around which he takes his foot off the floor.

• Journal of The Korean Society of Integrative Medicine
• /
• v.7 no.4
• /
• pp.33-41
• /
• 2019

Purpose : The muscle strength of iliopsoas (IL) was measured commonly in sitting position with hip and knee flexed 90°. However, there is no study to determine the muscle strength of IL in various test positions. Therefore, the purpose of this study was to compare the muscle strength of IL and muscle activity of rectus femoris (RF) according to test position and knee flexion angle. Methods : Twenty healthy subjects were participated for this study. The muscle strength of IL and muscle activity of RF were measured by hand-held dynamometer and surface electromyography during maximum voluntary isometric contraction (MVIC) of IL, respectively. The muscle strength of IL and muscle activity of RF was measured in 4 conditions as follows; 1) knee flexion angles 90 ° in supine, 2) 130 ° in supine position, 3) 90 ° in sitting, 4) 130 ° in sitting. Each condition were performed randomly by three repetitions. Results : The muscle strength of the IL was the main effect on the test position and knee flexion angle (p<.05), and the muscle activity of RF was the main effect only on the knee flexion angle (p<.05). There was also no interaction between the factors (p>.05). In supine position, the muscle strength of IL in knee flexion 130 ° was significantly less than that in knee flexion 90 ° (p<.0125). In knee flexion 90 °, the muscle strength of IL in supine position was significantly greater than that in sitting position (p<.0125). The muscle activity of RF in knee flexion 130 ° was significantly less than that in knee flexion 90 ° in supine and sitting positions (p<.0125). Conclusion : When the muscle strength of IL was measured in clinic and sports fields, the supine position with knee flexion 130 ° was recommended to prevent the muscle activation of RF and to maintain the trunk stability.

• Journal of the Ergonomics Society of Korea
• /
• v.30 no.5
• /
• pp.637-644
• /
• 2011

Objective & Background: When applying various evaluation tools that analyze work posture risk through observation, accurate measurement of body flexion angle is very important. Method: This study investigated differences and appropriateness of 5 different existing reference points commonly used in the analysis of the work posture. Twenty five ergonomist and trained professionals were participated in this study. A Same flexion angle was utilized for the evaluation of risk assessment of musculoskeletal disorders using five different reference points to investigate the degree of difference between them. To investigate how different the observers' preferred flexion angle measuring methods were compared to the ISO 11226 Reference Posture, a virtual body model was constructed using the Poser 6.0 program. Six types of body flexion postures were constructed, and since neck flexion differs according to body angle, five types of neck flexion postures were constructed with the trunk bending $20^{\circ}$ forward, making up a total of 30 virtual flexion postures. Results: Results showed that the observers used personally preferred reference points instead of reference points recommend in the evaluation tools. Also the results revealed the their seems to be 6 types of flexion angle for the trunk and 11 types of measurement methods for the neck flexion angle in the form of personally preferred reference points. The results showed that a mean difference of $14^{\circ}$($4{\sim}23^{\circ}$) occurred in the trunk, and a mean difference of $20^{\circ}$($-8{\sim}51^{\circ}$) occurred in the neck. To increase accuracy when using the 5 evaluation tools in combination, the ISO 11226 standards, observers' preferred flexion posture standards, and common flexion posture standards of the evaluation tools were compared with the reference points of the 5 evaluation tools. Results showed considerable variance in angle difference for each evaluation tool. Conclusion: According to the results of this study, considering the angle difference between the flexion angle reference points of the evaluation tool and the reference points selected by the observers, it is concluded that instead of personally preferred reference points, the standardized reference points to enhance the accuracy and the objectivity. Application: The result of this study can be used as reference guide to develop the standardized reference point in the future.

• Physical Therapy Korea
• /
• v.16 no.3
• /
• pp.9-15
• /
• 2009

The purpose of this study was to examine contraction of abdominal muscles on surface electromyographic (EMG) activity of superficial cervical flexors, rib cage elevation and angle of craniocervical flexion during deep cervical flexion exercise in supine position. Fifteen healthy subjects were participated for this study. All subjects performed deer cervical flexion exercise with two methods. The positions of two methods were no volitional contraction of abdominal muscles in hook-lying position with 45 degree hip flexion (method 1) and 90 degrees hip and knee flexion with feet off floor for inducing abdominal muscle contraction (method 2). Surface EMG activities were recorded from five muscles (sternocleidmastoid, anterior scaleneus, recuts abdominis, external oblique, internal oblique). And distance of rib cage elevation and angle of craniocervical flexion were measured using a three dimensional motion analysis system. The EMG activity of each muscle was normalized to the value of reference voluntary contraction (%RVC). The EMG activities, distance of rib cage elevation. and angle of craniocervical were compared using a paired t-test between two methods. The results showed that the EMG activities of sternocleidmastoid and anterior scaleneus during deep cervical flexion exercise in method 2 were significantly decreased compared to method 1 (p<.05). Distance of rib cage elevation and angle of craniocervical flexion were significantly decreased in method 2 (p<.05). The findings of this study indicated that deep cervical flexion exercise with contraction of abdominal muscles could be an effective method to prevent substitute motion for rib cage elevation and contraction of superficial neck flexor muscles.

• Journal of the Korean Arthroscopy Society
• /
• v.2 no.1
• /
• pp.77-79
• /
• 1998

Ganglion in the anterior cruciate ligament is quite rare finding at the time of knee arthroscopy. We experienced a 58 years old female pateint with a ganglion in the anterior cruciate ligamentwho complained gradual development of flexion contracture of left knee joint and treated with arthroscopic excision of ganglion resulted in freedom from flexion contracture of her knee joint.

• Physical Therapy Korea
• /
• v.21 no.4
• /
• pp.15-22
• /
• 2014

The purpose of this study was to determine the muscle activities of the erector spinae (ES), gluteus maximus (Gmax), gluteus medius (Gmed), and the hamstring (HAM) and the ratios of Gmax/ES, Gmax/HAM, and Gmed/HAM during the prone heel squeeze (PHS) with different knee flexion angles ($45^{\circ}$, $90^{\circ}$, and $135^{\circ}$). Fifteen young and healthy subjects (8 men, 7 women) were recruited for the study. Surface electromyography signals were collected on ES, Gmax, Gmed, and HAM during PHS. A separate one-way analysis of variance with repeated measures was used to determine the significance of the muscle activities of ES, Gmax, Gmed, and HAM and the ratios of Gmax/ES, Gmax/HAM, and Gmed/HAM with different knee flexion angles during PHS. There was a significant increase in the Gmax activity at the knee flexion of $90^{\circ}$ in comparison with that of the $45^{\circ}$ (p=.016). There were significant increases in the Gmed activity at the knee flexion of $90^{\circ}$ (p=.008) and $135^{\circ}$ (p=.006) in comparison with that of the $45^{\circ}$. There were significant decreases in the HAM activity at the knee flexion of $90^{\circ}$ (p=.009) and $135^{\circ}$ (p=.004) in comparison with that of the $45^{\circ}$. There were significant increases in the Gmax/HAM muscle activity ratio at the knee flexion of $90^{\circ}$ (p=.007) and $135^{\circ}$ (p=.012) in comparison with that of the $45^{\circ}$. There were significant increase in the Gmed/HAM muscle activity ratio at the knee flexion of $135^{\circ}$ in comparison with that of the $45^{\circ}$ (p=.008). The knee flexion of $90^{\circ}$ during PHS can induce decreasing activity of HAM and increasing activity of Gmax, and the knee flexion of $135^{\circ}$ during PHS can induce decreasing activity of HAM and increasing activity of Gmed. Hence, PHS with different knee flexion positions could be considered for the different target muscle.