The Effects of Posture on Neck Flexion Angle While Using a Smartphone according to Duration

( Sang-yong Lee ),( Dae-hee Lee ),( Seul-ki Han ) 대한물리의학회 2016 대한물리의학회지 Vol.11 No.3

PURPOSE: The purpose of this study was to examine changes in the neck flexion angle according to posture while using a smartphone and the duration of smartphone usage. METHODS: The subjects in this study were 16 healthy young students in their 20s. The subjects wore a cervical range of motion instrument. They were instructed to use a smartphone while standing, sitting on a chair, and sitting on the floor. In all postures, they could use the smartphone and use their arms freely while keeping their back connected to the wall or the back of the chair. When sitting on the floor, they assumed a cross-legged position. The neck flexion angle was measured at zero, three, six, and nine minutes for each posture. RESULTS: Neck flexion is affected by the posture while using a smartphone (p<.05). Neck flexion in the standing position is larger than that in the sitting on the floor position. Neck flexion was affected by smartphone usage duration (p<.05). In general, as usage time increases, the neck flexion angle increases as well. CONCLUSION: This study suggests that using smartphone in the standing position and for a short period of time is a method to reduce the neck flexion angle.

Intentionally Increased Flexion Angle of the Femoral Component in Mobile Bearing Unicompartmental Knee Arthroplasty

Kye-Youl Cho,Kang-Il Kim,송상준,Kyu-Jin Kim 대한슬관절학회 2018 대한슬관절학회지 Vol.30 No.1

Purpose: The purpose of this study was to determine the results of mobile bearing unicompartmental knee arthroplasty (UKA) with an intentionally increased flexion angle of the femoral component in patients requiring high flexion. Materials and Methods: We investigated 45 knees treated by UKA. Clinically, we measured the range of motion (ROM) and the American Knee Society (AKS) score preoperatively and at final follow-up and investigated complications. Radiologically, we measured the flexion angle of the femoral component, the posterior slope angle of the tibial component, the femorotibial angle and mechanical axis of the limb postoperatively. Results: The ROM was increased from 123° preoperatively to 139° at the final follow-up. The AKS knee and function scores increased from 59 and 68, respectively, preoperatively to 94 and 96, respectively, at the final follow-up. The flexion angle of the femoral component was 9.1°, and the posterior slope angle of the tibial component was 8.6°. There was one case of bearing dislocation in the largest femoral flexion angle case. Conclusions: The results might reflect the positive effect of an increased flexion angle of the femoral component up to 10° on ROM in mobile bearing UKA, which would contribute to better quality of life after UKA especially in populations requiring deep knee flexion.

The Effects of Coordinated Upper-limb Postures of Back, Shoulder, and Elbow Flexion Angles on the Subjective Discomfort Rating, Heart Rate, and Muscle Activities

Yong-Ku Kong,Soo-Jin Lee,Kyung-Suk Lee,Min-Tae Seo 대한인간공학회 2011 大韓人間工學會誌 Vol.30 No.6

Objective: This study was to investigate the effects of coordinated upper-limb body postures on the subjective discomfort rating, heart rate, and muscle activities. Background: Although generally many checklists such as OWAS, RULA, and REBA were applied to evaluate various body postures, the body postures were might be overestimated or underestimated because each body part(i.e., back, shoulder, and elbow etc.) was evaluated separately, and then added all rates of individual body parts to assess an overall risk level for the body posture in these methodologies. Methods: A total of 20 participants maintained 14 postures which were combinations of back, shoulder, and elbow flexion angles and then muscle activities, subjective discomfort, and heart rates were collected every three minute during a sustained 15 minute and 0.5kg weight holding task. Four muscle groups were investigated: erector spine, anterior deltoid, upper trapezius, triceps brachii. Results: Results showed that subjective discomfort was the lowest when the angle of back and shoulder were both 0°s, while the body posture with 45° of back angle and 45° shoulder angle was rated as the most subjective discomfort posture. In general, the subjective discomfort ratings increased as back and shoulder flexion angles increased. It was noted that, however, the subjective discomfort of body posture with a 45° back angle and 45° shoulder flexion angle was lower than that of body posture with a 0° back and 45° shoulder flexion angle. The research findings of heart rates and muscle activities showed similar results for the analyses of subjective discomfort ratings. Conclusions: The possible limitations of the current ergonomics evaluation techniques which assessing a body posture with summing all body part score after individually analyzed in this study. Based on the analyses of subjective discomfort, heart rate, and muscle activities, it was recommended that a use of effects of coordinated upper-limb body postures would be considered when one evaluates work-load for various working postures. Application: These findings can be used for developing a more accurate assessment checklist for working posture as well as preventing musculoskeletal disorders of workers in workplaces.

바로 누운 자세와 앉은 자세에서 무릎관절 굽힘 각도에 따른

박희용,정도영,차현규,원종혁 대한통합의학회 2019 대한통합의학회지 Vol.7 No.4

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. 목적 : 엉덩허리근의 근력은 일반적으로 앉은 자세에서 엉덩관절과 무릎관절을 90° 구부린 채로 실시된다. 그러나 아직까지 다양한 측정 자세에 따른 연구는 부족한 실정이다. 따라서 본 연구에서는 바로 누운 자세와 앉은 자세에서 무릎관절 굽힘 각도에 따른 엉덩허리근의 근력과 넙다리곧은근의 근활성도를 비교하여 측정 자세와 무릎관절 굽힘 각도가 엉덩허리근의 근력에 미치는 영향을 알아보고자 하였다. 방법 : 건강한 성인 남성 20명을 대상으로 바로 누운 자세와 앉은 자세에서 무릎관절 굽힘 각도에 따른 엉덩허리근의 근력과 넙다리곧은근의 근활성도를 비교하였다. 측정 자세와 무릎관절 굽힘 각도에 따른 4가지 조건에서 디지털 근력 측정기를 사용하여 엉덩허리근의 근력을 측정하였고, 표면 근전도를 사용하여 넙다리곧은근의 근활성도를 측정하였다. 결과 : 엉덩허리근의 근력은 측정 자세와 무릎관절 굽힘 각도에 대해 모두 유의한 주효과가 있었으며(p<.05), 넙다리곧은근의 근활성도는 무릎관절 굽힘 각도에 대해서만 유의한 주효과가 있는 것으로 나타났다(p<.05). 사후검정 결과, 엉덩허리근의 근력은 바로 누운 자세에서 무릎관절 굽힘 90° 자세 보다 130° 자세에서 유의하게 낮았다(p<.0125). 또한 앉은 자세에서 무릎관절 굽힘 90° 자세 보다 바로 누운 자세에서 무릎관절 굽힘 90°에서 유의하게 높았다(p<.0125). 넙다리곧은근 근활성도에 대한 사후검정 결과, 모든 자세에서 무릎관절 굽힘 90° 자세 보다 130° 자세에서 유의하게 낮았다(p<.0125). 결론 : 측정 자세와 무릎관절의 굽힘 각도가 엉덩허리근의 근력에 영향을 미친다는 것을 의미한다. 따라서 임상 혹은 스포츠 분야에서의 엉덩허리근의 근력 측정 시 체간의 안정성을 유지하고 넙다리곧은근의 근활성도를 줄이기 위해 무릎관절 굽힘 130° 굽힘 한 바로 누운 자세를 추천한다.

굴곡-신연기법과 낙차 교정법이 허리 척추사이원반 탈출증 환자의 시각적 상사 척도 및 엉치뼈 각에 미치는 영향

오현주,최석주,이관섭,최지운,Oh, Hyun-Ju,Choi, Seok-Joo,Lee, Kwan-Sub,Choi, Ji-Oun 대한물리치료과학회 2018 대한물리치료과학회지 Vol.25 No.3

Background: In order to find out the effect of therapy methods through Flexion-distraction technique and drop technique on pain, sacral angle of patients with lumbar herniated intervertebral disc targeting patients with lumbar herniated intervertebral disc due to L5-S1. Method: This study was to present the directivity of the therapy method for lumbar herniated intervertebral disc by comparing and analyzing the spinal decompression therapy and provide an effective treatment method to patients with lumbar herniated intervertebral disc by identifying the therapeutic effect of Flexion-distraction technique and drop technique. The research period is March 1, 2018 to June 30, 2018 and subjects are the patients diagnosed as lumbar herniated intervertebral disc due to L5-S1 by their doctor through clinical findings and medical equipment such as X-ray, CT, MRI etc. Among patients who visited and hospitalized in S Orthopaedics located in Daegu and 30 female patients with sacral angle of more than $30^{\circ}$ were randomly classified into 15 people and we carried out treatment three times a week for 8 weeks for 15 people in the experimental group applying Flexion-distraction technique and drop technique and 15 people in the control group applying spinal decompression therapy to compare and analyze the changes in pain, sacral angle of patients with lumbar herniated intervertebral disc. Result: According to the results of this study, changes in the Visual Analogue Scale showed statistically significant differences in both the experimental group and control group(p<.05), while there was statistically significant difference in the comparison between groups before and after measurement of experimental group (p<.05). In the comparison within two groups of sacral angle, both groups showed statistically significant difference(p<.05) but there was no statistically significant difference in the comparison of scores between groups before and after measurement of each group(p>.05). Discussion: All those results the above proved that we need to confirm various benefits of the therapy with the flexion-distraction technique and drop technique, and the findings of the concerned study will possibly become useful information when doctors actually work on a therapy to treat patients with the lumbar herniated intervertebral disc.

트레드밀 걷기 시 무릎관절 각도와 트레드밀 경사도가 폐기능에 미치는 영향

한동욱(Dong-Wook Han) 대한심장호흡물리치료학회 2020 대한심장호흡물리치료학회지 Vol.8 No.2

Purpose : This study aims to examine the effect of treadmill slope and knee flexion angle on lung function while walking on the treadmill. Methods : A total of 15 healthy female students attending S university in B city were enrolled in this study. A gas analyzer (K4b2, COSMED, Italy) was used to measure the lung function. Using a knee brace that could limit movement, the knee flexion angles were set to 0˚, 15˚, 30˚, and 45˚. The treadmill slope (h/p/Cosmos, Proxomed, Germany) was set at 0%, 5%, and 10%. The items of lung functions included respiratory frequency (RF), tidal volume (VT), minute ventilation (VE), oxygen consumption (VO2), and carbon dioxide output (VCO2). The speed of treadmill was 4.3 km/h. The measurement time was 5 minutes for each session. However, only the values of measurement for 3 minutes excluding the first one minute and the last one minute during walking were used for analysis. Results : In this study, the results showed that RF increased as the treadmill slope increased at knee flexion of 0° (p < 0.05), 15° (p < 0.05), and 30° (p < 0.05). However, depending on the increase in knee flexion limitation at treadmill slopes of 0%, 5%, and 10%, VT, VE, VO2, and VCO2 were not changed. Also, based on the increase in knee flexion limitation at treadmill slopes of 0% (p < 0.05) and 5% (p < 0.05), RF increased. But there was no significant difference at 10% of slope. VT increased as the treadmill slope increased at knee flexion of 30° (p < 0.05) and 45° (p < 0.05). VE, VO2, and VCO2 increased as the treadmill slope increased at knee flexion of 0° (p < 0.05), 15° (p < 0.05), 30° (p < 0.05), and 45° (p < 0.05). Conclusion : In conclusion, the treadmill slope was found to have a greater effect on lung function than that of the knee flexion angle.

A Comparison Study of Cervical Flexion-Relaxation Ratio in the Normal and Forward Head Postures

( Sang-seok Yeo ),( Jung-won Kwon ) 대한물리치료학회 2020 대한물리치료학회지 Vol.32 No.6

Purpose: This study aimed to examine the effects of forward head posture on the flexion-relaxation ratio (FRR) and muscle activity during sustained neck flexion and to investigate the correlation between craniovertebral angle and FRR. Methods: Nineteen subjects participated in this study and were allocated to a forward head posture (FHP) group or a non-forward head posture (NFHP) group. Craniovertebral angle (CVA) and FRR were measured in all subjects, and all participants performed a standardized cervical flexion-extension movement in two phases: Phase I, sustained cervical full flexion for 5s; and Phase II, cervical extension with the return to the starting position for 5s. The value of CVA has calculated three times, and the value of FRR was measured three times in order to obtain the mean value. Results: FRR values in the FHP and NFHP group were significantly different (p< 0.05). Phase I was significantly different, but the Phase II was not significantly different between the FHP and NFHP group (p >0.05). There was a significant correlation between the muscle activity of Phase I and CVA (p< 0.05). However, FRR and the muscle activity of the Phase II were not a significant correlation with the CVA (p >0.05). Conclusion: FHP increases the muscle activity of the cervical erector spinae during sustained neck flexion and reduces FRR, which can cause fatigue in the cervical erector spinae. In addition, for those with a smaller CVA, muscle activity of the cervical erector spinae is increased during sustained neck flexion, which can increase neck muscle tension.

Comparison of EMG Activity during Trunk Forward Bending with and without Limited Lumbar Flexion Angle

Soo-Hyun Bae(Soo-Hyun Bae),Duk-Hyun An(Duk-Hyun An),Jae-Seop Oh(Jae-Seop Oh),Won-Gyu Yoo(Won-Gyu Yoo) 한국임상움직임치료학회 2022 한국임상움직임치료학회지 Vol.2 No.1

Background: Several studies have evaluated the relationship of low back pain with lumbar flexion angle and muscle activity. However, there are scant studies on the relationship between the ratio of normalized muscle activities and lumbar flexion angle. The lumbar flexion angle has been used to diagnose low back pain and to determine the predominantly used muscles during trunk forward bending in asymptomatic individuals. Prolonged sitting is associated with a slumped or upright sitting posture, which can affect the soft tissues in the lumbar region. Objectives: The purpose of this study was to determine the predominantly used muscles during forward bending, holding, and re-extension based on EMG data. Methods: In total, 20 participants were screened for inclusion. The activities of the longissimus [ES (T12)], erector spinae [ES (L3)], gluteus maximus, and hamstring muscles were examined during forward bending, holding the posture, and re-extension. The mean lumbar flexion angle was used to categorize the patients. Patients with a short hamstring length during forward bending were excluded. Results: The ES (T12) and gluteus maximus : hamstring, and ES (L3) : hamstring activity ratios were compared between the groups during the three phases. The data were normalized to calculate the percent reference voluntary contraction (%RVC). The gluteus maximus : hamstring and ES (L3) : hamstring ratios during re-extension were significantly different between the groups. Conclusions: In the experimental group, the participants showed greater activation of the hamstrings than the gluteus maximus and erector spinae during re-extension. Future studies should include a larger sample size and use more precise eligibility criteria.

양반 앉은 자세에서의 SPINE-GUARD 착용이 허리부위의 코브각 및 통증 그리고 몸통 굽힘각도의 변화에 미치는 영향

최석주(SeokJoo Choi),정봉재(BongJae Jeong),최완석(WanSuk Choi) 한국방사선학회 2011 한국방사선학회 논문지 Vol.5 No.5

앉은 자세를 장시간 유지하면 허리의 만곡에 변화가 오면서 통증이 발생하게 된다. 본 연구에서는 양반 앉은자세에서 SPINE-GUARD(허리 안정화 벨트) 착용이 허리뼈의 코브각과 허리통증 그리고 몸통 굽힘각도의 변화에 미치는 영향에 대해 알아보았다. 대상자 15명(남자)은 2주 동안 주 5회 매회 90분씩 벨트를 착용한 채로 영화를 감상하거나 강의를 들었다. 허리뼈의 코브각은 착용전 48.36±14.57에서 착용후 28.09±11.63로 유의한 감소를 보였다(p<0.05). 통증은 착용전 4.53±2.36이고, 착용후 2.733±2.153로 유의하게 감소하였다(p<0.05). 몸통의 굽힘각도 또한 착용전 82.33±20.30에서 착용 후 70.2±19.43로 유의한 감소를 보였다(p<0.05). 이것으로 보아 SPINE-GUARD의 착용은 허리뼈의 코브각 및 몸통굽힘각도의 변화 그리고 통증의 감소에 영향을 주는 것으로 사료된다. When we keep sitting for a long time, we end up with pain due to changes in the curvature in the waist. This study examined impacts from the wearing of a SPINE-GUARD(belt for the waist stabilization) on a cross-legged sit on variations of the Cobb’s angle, lower back pain and trunk flexion angle. 15 men for the examination have watched movies or attended lectures while wearing a belt for 90 minutes per round for every five rounds for two weeks. The Cobb’s angle showed a significant decrease from 48.36±14.57 before wearing to 28.09±11.63 after wearing (p<0.05). Pain decreased from 4.53±2.36 before wearing to 2.733±2.153 after wearing (p<0.05). The trunk flexion angle also showed a significant decrease from 82.33±20.30 before wearing to 70.2±19.43 after wearing (p<0.05). Given these findings, the wearing of a SPINE-GUARD seems to affect variations of the Cobb’s angle and trunk flexion angle, and decrease of lower back pain.

The Correlation between Posterior Tibial Slope and Maximal Angle of Flexion after Total Knee Arthroplasty

( Keong Hwan Kim ),( Seong Il Bin ),( Jong Min Kim ) 대한슬관절학회 2012 대한슬관절학회지 Vol.24 No.3

Purpose: The purpose of this study was to evaluate the correlation between the posterior tibial slope and the maximal angle of flexion after total knee arthroplasty. Materials and Methods: Seventy nine cases (63 patients, 60 females and 3 males), which received total knee arthroplasty with the Nexgen LPS system from Jan 2001 to Jan 2004, were enrolled. We divided all cases into two subsets in two ways. Firstly, group A (up to 10°, 44 cases) and group B (over 10°, 35 cases) were divided according to the mean value of the postoperative posterior tibial slope. Secondly, group α (up to -4°, 39 cases) and group β (over -4°, 40 cases) were divided according to the mean difference between the preoperative posterior tibial slope and the postoperative posterior tibial slope. We compared the maximal angle of flexion between group A and group B, group α and group β, respectively. Results: There was no significant difference between group A and group B, and also between group α and group β in terms of maximal angle of flexion. Conclusions: There was no significant correlation between the postoperative posterior tibial solpe and the maximal angle of flexion.