Effect of the Neck Retraction Taping (NRT) on Forward Head Posture and the Upper Trapezius Muscle during Computer Work

[Purpose] The purpose of this study was to investigate the effect of neck retraction taping on forward head posture and the upper trapezius muscle of computer workers during computer work. [Subjects] Twelve males aged 20–30 years were recruited. [Methods] We measured forward head angle and upper trapezius muscle activity during computer work before and after NRT. [Results] The FHP angle significantly decreased during computer work performed with NRT compared to without NRT. The UT muscle activity was also significantly decreased during computer work performed with NRT compared to without NRT. [Conclusion] We think that the taping tension provided by NRT may have provided a mechanical effect that prevented FHP. NRT may also encourage a proper head posture in patients unfamiliar with the neck retraction posture.Key words: Forward head posture, Neck retraction, Taping     

Differences in lumbar and pelvic angles and gluteal pressure in different sitting postures

[Purpose] To investigate the effects of erect sitting, slouched posture with cross-legged sitting, and erect posture with cross-legged sitting on the lumbar and pelvic angles, and gluteal pressure. [Subjects] For the experiments, 17 healthy women were recruited. [Methods] All subjects were asked to perform three sitting postures: erect sitting, slouched posture with cross-legged sitting, and erect posture with cross-legged sitting. Lumbar and pelvic angles were measured using a three-dimensional motion-capture system, and gluteal pressure was measured using a pressure mat. [Results] Compared to erector sitting, slouched posture with cross-legged sitting showed significantly greater lumbar flexion, posterior pelvic tilt, and left pelvic tilt. Compared to erect sitting, erect posture with cross-legged sitting showed significantly greater lumbar flexion and posterior pelvic tilt. Compared to erect posture with cross-legged sitting, slouched posture with cross-legged sitting showed significantly greater lumbar flexion and posterior pelvic tilt. Compared to erect sitting and erect posture with cross-legged sitting, slouched posture with cross-legged sitting showed significantly greater left gluteal pressure; there was no significant difference in right gluteal pressure. [Conclusion] An erect posture can reduce changes in lumbar and pelvic angles, and gluteal pressure compared to a slouched posture during cross-legged sitting.Key words: Cross-legged sitting, Lumbar and pelvic angles, Gluteal pressure     

A Sloped Seat Wedge Can Change the Kinematics of the Lumbar Spine of Seated Workers with Limited Hip Flexion

[Purpose] The purpose of this study was to determine whether a wedge type seat decreases the lumbar flexion angle of seated workers with limited hip flexion. [Subjects] Twelve sedentary workers with limited hip flexion were recruited. [Methods] Three seat surfaces were used: a level surface, a forward-inclining wedge, and a backward-reclining wedge. The angles of lumbar flexion and pelvic tilt were measured using a three-dimensional motion analysis system. Differences in kinematic data of the subjects seated on the three seat surfaces were analyzed using repeated one-way analysis of variance. [Results] The degree of lumbar flexion decreased significantly when using the forward-inclining wedge compared with the level surface and backward-reclining wedge. [Conclusion] These findings suggest that sitting on a forward-inclining wedge may be useful for minimizing the compensatory lumbar flexion of individuals with limited hip flexion who work in a seated position.Key words: Kinematics, Limited hip flexion, Seat wedge     

Comparison of Upper Cervical Flexion and Cervical Flexion Angle of Computer Workers with Upper Trapezius and Levator Scapular Pain

[Purpose] In this study, we compared upper cervical flexion and cervical flexion angle of computer workers with upper trapezius and levator scapular pain. [Subject] Eight male computer workers with upper trapezius muscle pain and eight others with levator scapular muscle pain participated. [Methods] Each subject was assessed in terms of upper cervical flexion angle and total cervical flexion angles using a cervical range of motion instrument after one hour of computer work. [Results] The upper cervical flexion angle of the group with levator scapular pain was significantly lower than that of the group with upper trapezius pain after computer work. The total cervical flexion angle of the group with upper trapezius pain was significantly lower than that of the group with levator scapular pain after computer work. [Conclusion] For selective and effective intervention for neck pain, therapists should evaluate upper and lower cervical motion individually.Key words: Cervical range of motion, Neck pain, Upper cervical flexion     

Characteristics of Cervical Position Sense in Subjects with Forward Head Posture

[Purpose] The purpose of this study was to investigate the effect of forward head posture (FHP) on proprioception by determining the cervical position-reposition error. [Subjects and Methods] A sample population was divided into two groups in accordance with the craniovertebral angle: the FHP group and the control group. We measured the craniovertebral angle, which is defined as the angle between a horizontal line passing through C7 and a line extending from the tragus of the ear to C7. The error value of the cervical position sense after cervical flexion, extension, and rotation was evaluated using the head repositioning accuracy test. [Results] There were significant differences in the error value of the joint position sense (cervical flexion, extension, and rotation) between the FHP and control groups. In addition, there was an inverse correlation between the craniovertebral angle and error value of the joint position sense. [Conclusion] FHP is associated with reduced proprioception. This result implies that the change in the muscle length caused by FHP decreases the joint position sense. Also, proprioception becomes worse as FHP becomes more severe.Key words: Forward head posture, Joint position sense, Proprioception     

The effects of horse-riding simulator exercise and Kendall exercise on the forward head posture

[Purpose] The aim of this study was to examine the effects of horse-riding simulator exercise and Kendall exercise on forward head posture. [Subjects and Methods] Thirty elderly college students with a forward head posture were randomly divided into two groups for 15 persons each, a horse-riding simulator group and Kendall exercise group, and performed exercise for eight weeks. [Results] The horse-riding simulator group and Kendall exercise group showed significant differences after the intervention in New York state posture rating, craniovertebral angle, and cranial rotation angle. The horse-riding simulator group showed a significantly smaller value than the Kendall exercise group for New York state posture rating evaluation after the intervention. [Conclusion] The results of this study indicate that horse-riding simulator exercise is more effective on forward head posture than Kendall exercise. Therefore, horse-riding simulator exercise can be used as a new simple treatment method for the ever-growing forward head posture.Key words: Neck pain, Posture, Horse-riding simulator     

Neck kinematics and sternocleidomastoid muscle activation during neck rotation in subjects with forward head posture

[Purpose] The present study investigated differences in the kinematics of the neck and activation of the sternocleidomastoid (SCM) muscle during neck rotation between subjects with and without forward head posture (FHP). [Subjects and Methods] Twenty-eight subjects participated in the study (14 with FHP, 14 without FHP). Subjects performed neck rotation in two directions, left and right. The kinematics of rotation-lateral flexion movement patterns were recorded using motion analysis. Activity in the bilateral SCM muscles was measured using surface electromyography. Differences in neck kinematics and activation of SCM between the groups were analyzed by independent t-tests. [Results] Maintaining FHP increased the rotation-lateral flexion ratio significantly in both directions. The FHP group had significantly faster onset time for lateral flexion movement in both directions during neck rotation. Regarding the electromyography of the SCM muscles during neck rotation in both directions, the activity values of subjects with FHP were greater than those of subjects without FHP for the contralateral SCM muscles. [Conclusion] FHP can induce changes in movement in the frontal plane and SCM muscle activation during neck rotation. Thus, clinicians should consider movement in the frontal plane as well as in the sagittal plane when assessing and treating patients with forward head posture.Key words: Axial rotation, Cervical movement, Forward head posture     

Comparison of lumbar repositioning error according to different lumbar angles in a flexion pattern (FP) subgroup of patients with non-specific chronic low back pain

[Purpose] This study determined the change in lumbar position sense according to lumbar angles in a flexion pattern (FP) subgroup of patients with non-specific chronic low back pain (NCSLBP). [Subjects] Thirteen subjects with FP low back pain participated. [Methods] The lumbar repositioning error (RE) of subjects was measured between a neutral starting position and re-position phases at three angles, in sitting and standing upright positions. [Results] Lumbar RE was significantly greater during lumbar flexion at a 30° angle in the sitting position than in the other tasks. [Conclusion] In the flexion-related subgroup, the lumbar RE measurement may be a more sensitive evaluation method using a lumbar flexion angle of 30° while in the sitting position, compared with other angles in sitting or standing positions.Key words: Flexion pattern, Low back pain, Repositioning error     

Kinematic analysis of the lower cervical spine in the protracted and retracted neck flexion positions

[Purpose] The aim of this study was to analyze lower cervical spine kinematics in protracted and retracted neck flexion positions in healthy people. [Subjects and Methods] The craniovertebral angle (CVA) and intervertebral body angles of the lower cervical spine of 10 healthy individuals were analyzed using fluoroscopy in a neutral sitting with the head in the neutral (N), protracted (Pro), and retracted (Ret) positions and with the neck in full flexion with the head in the neutral (N-fx), protracted (Pro-fx), and retracted (Ret-fx) positions. [Results] There were significant differences in the CVA and intervertebral body angle at the C3–4 level, and the Ret position showed the highest values followed by the N and Pro positions. Regarding the intervertebral body angle at the C4–5 level, the Pro position showed a higher value than the N and Ret positions. At the C6–7 level, the Pro position showed the lowest value compared with the N and Ret positions. In the CVA, the Ret-fx position showed a higher value than the N-fx and Ret-fx positions. [Conclusion] The results suggest that in the neutral sitting position, protraction is an ineffective posture due to overstress of the C6–7 segment, which is placed in a hyperflexed position at this level. Instead, retraction is the recommend posture for the patient with C6–7 degeneration, which makes for a more flexed position in the upper cervical spine and a less flexed position in the lower cervical spine.Key words: Head posture, Intervertebral body angle, Lower cervical spine     

The correlation between calcaneal valgus angle and asymmetrical thoracic-lumbar rotation angles in patients with adolescent scoliosis

[Purpose] This study aimed to provide a predictable evaluation method for the progression of scoliosis in adolescents based on quick and reliable measurements using the naked eye, such as the calcaneal valgus angle of the foot, which can be performed at public facilities such as schools. [Subjects and Methods] Idiopathic scoliosis patients with a Cobb’s angle of 10° or more (96 females, 22 males) were included in this study. To identify relationships between factors, Pearson’s product-moment correlation coefficient was computed. The degree of scoliosis was set as a dependent variable to predict thoracic and lumbar scoliosis using ankle angle and physique factors. Height, weight, and left and right calcaneal valgus angles were set as independent variables; thereafter, multiple regression analysis was performed. This study extracted variables at a significance level (α) of 0.05 by applying a stepwise method, and calculated a regression equation. [Results] Negative correlation (R=−0.266) was shown between lumbar lordosis and asymmetrical lumbar rotation angles. A correlation (R=0.281) was also demonstrated between left calcaneal valgus angles and asymmetrical thoracic rotation angles. [Conclusion] Prediction of scoliosis progress was revealed to be possible through ocular inspection of the calcaneus and Adams forward bending test and the use of a scoliometer.Key words: Scoliosis, Asymmetrical lumbar rotation angle, Asymmetrical thoracic rotation angle     

Effect of postural angle on back muscle activities in aging female workers performing computer tasks

[Purpose] This study investigated the effects of postural angle on back muscle activity during a computer task in aging women. [Subjects] Seventeen women ≥50 years old participated. [Methods] The participants were instructed to perform computer-related tasks for 20 minutes on a workstation that simulated typical office working conditions. Back posture was measured from the measured trunk and pelvic angles. Electromyography activities were recorded simultaneously from the cervical erector spinae, longissimus, and multifidus muscles. [Results] The lowest mean percentages of maximum voluntary contraction for the cervical erector spinae and longissimus muscles were obtained when the upper trunk and pelvic angles were between 0° to −5° from the sagittal plane. The back muscle activities increased as the upper trunk and pelvic angles exceeded 0°. Statistical analysis showed significant correlations between upper trunk angle and cervical erector spinae and longissimus muscle activities. Similarly, pelvic angle was significantly correlated with cervical erector spinae and multifidus muscle activities. [Conclusion] A neutral back posture minimizes muscle activities in aging women performing computer tasks.Key words: Postural angle, Muscle activity, Aging     

Comparison of the Symmetry of Right and Left Lateral Cervical Flexion and Rotation and the Cervical FRR in Young Computer Workers

[Purpose] This study compared the symmetry of right and left lateral cervical flexion and rotation, and the cervical flexion-relaxation ratio (FRR) in young computer workers in Korea. [Subjects and Methods] Twenty computer workers (14 males and 6 females) participated in this study. We measured their right and left lateral cervical flexion, rotation, and FRR. [Results] Right and left lateral flexion and right and left rotation showed no significant differences between the sides. The left cervical FRR was significantly lower than the right cervical FRR. [Conclusion] The cervical FRR, expressed as a numerical value, is a more sensitive marker for measuring neuromuscular changes associated with mild asymmetry than CROM.Key words: Cervical range of motion, Flexion-relaxation ratio, Muscle imbalance     

Influence of neck pain on cervical movement in the sagittal plane during smartphone use

[Purpose] Smartphone use reportedly changes posture. However, how neck posture is altered in smartphone users with neck pain is unknown. This study examined changes in the posture of young adults with and without mild neck pain (MNP) when using a smartphone. [Subjects] Thirteen control subjects and 14 subjects with MNP who used smartphones were recruited. [Methods] The upper cervical (UC) and lower cervical (LC) angles in the sagittal plane were measured using an ultrasound-based motion analysis system while the seated subjects used a smartphone for 5 min. [Results] During smartphone use, the MNP group exhibited greater UC and LC flexion angles than the control group. [Conclusion] These findings suggest that young adults with MNP are more careful and more frequently utilize a neutral neck posture than young adults without MNP when using a smartphone while sitting.Key words: Smartphone, Cervical flexion, Young adult     

The Intra- and Inter-rater Reliabilities of the Forward Head Posture Assessment of Normal Healthy Subjects

[Purpose] Assessment of posture is an important goal of physical therapy interventions for preventing the progression of forward head posture (FHP). The purpose of this study was to determine the inter- and intra-rater reliabilities of the assessment of FHP. [Subjects and Methods] We recruited 45 participants (20 male subjects, 25 female subjects) from a university student population. Two physical therapists assessed FHP using images of head extension. FHP is characterized by the measurement of angles and distances between anatomical landmarks. Forward shoulder angle of 54° or less was defined as FHP. Intra- and inter-rater reliabilities were estimated using Kendall’s Taub correlation coefficients. [Results] Intra-class correlation of intra-rater measurements indicated an excellent level of reliability (0.91), and intra-class correlation of inter-rater measurements showed a good level of reliability in the assessment of FHP (0.75). [Conclusion] Assessment of FHP is an important component of evaluation and affects the design of the treatment regimen. The assessment of FHP was reliably measured by two physical therapists. It could therefore become a useful method for assessing FHP in the clinical setting. Future studies will be needed to provide more detailed quantitative data for accurate assessment of posture.Key words: Forward head posture, Reliability, Posture assessment     

Immediate effects of the activation of the affected lower limb on the balance and trunk mobility of hemiplegic stroke patients

[Purpose] The purpose of this study was to determine the effects of the activation of the affected lower limb on balance and the trunk hemiplegic mobility of stroke patients. [Subjects] The gait group (GG) consisted of 6 subjects with hemiplegia and the non-gait group (NGG) consisted of 6 hemiplegic subjects. [Methods] The subjects in both groups were given foot facilitation training once for 30 min. The Spinal Mouse was used to measure the spinal alignment and the Berg balance scale (BBS) and sensory tests were also performed. [Results] In the GG, the sacral hip in upright to flexion, the lumbar spine in upright to extension, and the sacral hip and lumbar spine in flexion to extension showed significant increases in their angles after the intervention. In addition, there was a significant increase in the angle of the lumbar spine during extension from an upright position in the NGG. The BBS scores of both groups also increased significantly. [Conclusion] The intervention resulted in improvements in the angle of anterior pelvic tilt in the GG, and subjects in the NGG showed more extension of the thorax, which was regarded as compensation to avoid falling forward when flexing from an upright position. However, when extending backward from an upright position, both groups tended to control balance by using more lumbar flexion to keep the center of mass (COM) within the base of support (BOS). Both groups had better BBS scores.Key words: Balance, Stroke, Trunk     

Comparison of the Lumbar Flexion Angle and EMG Activity in Trunk Muscles in Individuals with and without Limited Hip Flexion Range of Motion during Visual Display Terminal Work with Cross-Legged Sitting

[Purpose] The purpose of this study was to compare the lumbar flexion angle and electromyography (EMG) measurements of trunk muscle activity in individuals with and without limited hip flexion range of motion (ROM) during visual display terminal (VDT) work with cross-legged sitting. [Subjects] The 15 participants included a control group with sufficient hip flexion ROM (n = 7) and an experimental group with limited hip flexion ROM (n = 8). [Methods] All subjects performed VDT work with cross-legged sitting. The lumbar flexion angle was measured using a three-dimensional motion capture system, and the trunk muscle activity was recorded using a surface EMG system during VDT work with cross-legged sitting. The differences in trunk flexion angle and trunk muscle activity between the two groups were analyzed using independent t-tests. [Results] The lumbar flexion angle was significantly greater in the experimental group than the control group, although trunk muscle activity did not differ between the two groups. [Conclusion] These findings suggest that limited hip flexion leads to greater lumbar flexion during cross-legged sitting.Key words: Cross-legged sitting, Electromyography, Lumbar flexion     

Relationship between joint motion and acceleration during single-leg standing in healthy male adults

[Purpose] The purpose of this study was to clarify the relationship between acceleration and joint movement by synchronizing accelerometers and a three-dimensional motion analysis system, and to show the utility of an accelerometer as a postural control assessment tool. [Subjects and Methods] Head, lumbar, shank accelerations and various joint angles during single-leg standing were measured of 20 healthy males. Root mean squares of acceleration and joint angle were calculated. Fast Fourier transform analysis was performed for head, lumbar, and shank accelerations, and the median frequencies were calculated. Then, principal component analysis was performed for the median frequency of each acceleration. Stepwise multiple regression analysis was also used to examine the relationship between joint angle and acceleration. [Results] The score of the first principal component was highest for shank acceleration, while that of the second principal component was highest for lumbar and head accelerations. In multiple regression analysis, hip flexion/extension and adduction/abduction were identified as variables associated with head acceleration. [Conclusion] We were able to confirm the aggregation of acceleration into two components, which we interpreted as postural control strategies using primarily the ankle and hip joints. Furthermore, though multiple regression analysis, we were able to clarify the joint movement indicated by acceleration of each segment.Key words: Postural control, Acceleration, Ankle sprain     

Effect of the Shoulder Flexion Angle in the Sagittal Plane on the Muscle Activities of the Upper Extremities when Performing Push-up plus Exercises on an Unstable Surface

[Purpose] The purpose of this study was to investigate the effect of the shoulder flexion angle on the muscle activities of the upper extremities when performing the push-up plus exercise (PUPE) on an unstable surface with the forearm in the external rotation position. [Subjects] The subjects were conducted on 15 normal male adults. [Methods] A sling device was used for the unstable surface, and PUPE was performed with the forearm in the external rotation position. The shoulder flexion angles measured in the sagittal plane were 110°, 90°, and 70°. Electromyography was used for a comparitive analysis of the muscle activities of the serratus anterior (SA), the pectoralis major (PM), and the upper trapezius (UT). [Results] In the intra-group comparison, the muscle activity of SA was statistically the highest when the shoulder-flexion angle was 110°. [Conclusion] performing PUPE on an unstable surface, the muscle activity of the SA is activated the most when the shoulder flexion angle is 110° and the forearm is in the external rotation position.     

Analysis of Balance Ability Dependent on the Angle of the Knee Joint in Females in Their 20s

The aim of this study was to investigate how balance ability according to angle of the knee joint changes in young female adults wearing a knee orthosis. [Methods] This study was conducted with 11 healthy female adults. The subjects used a knee brace that could be set to angles of 0°, 15°, and 30° of knee flexion. The ability to balance was evaluated by balance assessment. A total of four postures were used for measurements: a forward-facing posture with the eyes open on a stable surface (NO), a forward-facing posture with the eyes closed on a stable surface (NC), a forward-facing posture with the eyes open on an unstable surface (PO), and a forward-facing posture with the eyes closed on an unstable surface (PC). [Results] Regarding the weight distribution index and stability index on a stable surface, there was no interaction according to whether there was visual deprivation or not or according to knee flexion angle. Furthermore, the stability index on an unstable surface showed no interaction according to whether there was visual deprivation or not or according to knee flexion angle. But the WDI on a stable surface showed no interaction according to whether there was visual deprivation or not or according to knee flexion angle. [Conclusion] There were significant differences in the knee extension range of motion of normal elderly people and knee osteoarthritis, and the quadriceps femoris played an important role in knee function in individuals with knee osteoarthritis.Key words: Osteoarthritis, Knee orthosis, Balance     

Lumbar Extension during Stoop Lifting is Delayed by the Load and Hamstring Tightness

[Purpose] This study investigated the relationship between lumbar pelvic rhythm and the physical characteristics of stoop lifting. [Subjects and Methods] Participants performed a stoop lifting task under two conditions: with and without load. We assessed the lumbar kyphosis and sacral inclination angles using the SpinalMouse^® system, as well as hamstring flexibility. During stoop lifting, surface electromyograms and the lumbar and sacral motions were recorded using a multi-channel telemetry system and flexible electrogoniometers. [Results] In the initial phase of lifting, lumbar extension was delayed by load; the delay showed a negative correlation with sacral inclination angle at trunk flexion, whereas a positive correlation was observed with electromyogram activity of the lumbar multifidus. Additionally, a positive correlation was observed between sacral inclination angle and hip flexion range of motion during the straight leg raise test. [Conclusion] We found that a disorder of the lumbar pelvic rhythm can be caused by both load and hamstring tightness. In the initial phase of stoop lifting, delayed lumbar extension is likely to lead to an increase in spinal instability and stress on the posterior ligamentous system. This mechanism shows that stoop lifting of a load may be harmful to the lower back of people with hamstring tightness.Key words: Lifting, Lumbar pelvic rhythm, Hamstring flexibility