Neck Flexion Angle Research Articles

Comparing repeated end range movements and Kinesio taping effects on head and neck movement pattern and discomfort in smartphone users

IntroductionUsing smartphones has increased exponentially, especially after the COVID-19 pandemic. However, there is a relationship between neck flexion angle during working with a smartphone and neck musculoskeletal disorders. Therefore, this study compares the effect of Kinesio taping and Repeated End Range Movements (RERM) on head and neck flexion angles changes during texting and discomfort after texting with a smartphone. MethodTwenty-four smartphone users participated in this cross-over study. All of 24 subjects were experimented with the control, RERM and taping conditions. They filled Numeric Rating Scale questionnaire before and after 30 min of texting. In addition, their head and neck flexion angles were measured during the task by photogrammetry. ResultsIn the RERM group, individuals felt significantly less discomfort than the control group after the task (P = 0.032). Although the slope of average head and neck flexion angles linear regression lines of all the three groups was positive before the break time, it became negative in the taping and control groups after the break time. In addition, the linear regression of average head and neck flexion angles of the RERM group was significantly different (P < 0.001). ConclusionRERM can effectively maintain normal head and neck movement pattern during and reduce neck discomfort after texting on smartphone.

User-centred design, validation and clinical testing of an anti-choking mug for people with Parkinson’s disease

Oropharyngeal dysphagia, or difficulty initiating swallowing, is a frequent problem in people with Parkinson’s disease (PD) and can lead to aspiration pneumonia. The efficacy of pharmacological options is limited. Postural strategies, such as a chin-down manoeuvre when drinking, have had some degree of success but may be difficult for people who have other limitations such as dementia or neck rigidity, to reproduce consistently. Using a user-centred design approach and a multidisciplinary team, we developed and tested an anti-choking mug for people with PD that helps angle the head in the optimum position for drinking. The design reflected anthropometric and ergonomic aspects of user needs with features including regulation of water flow rate and sip volume, an inner slope, a thickened handle and a wide base, which promoted a chin-down posture when used. Prototype testing using digital technology to compare neck flexion angles (the primary outcome), plus clinical outcomes assessed using standard tools (Swallowing Clinical Assessment Score in Parkinson’s Disease (SCAS-PD) and Movement Disorder Society-Unified Parkinson’s Disease Rating Scale (MDS-UPDRS) Parts II and III), found significant improvements in a range of parameters related to efficient swallowing and safe drinking when using the anti-choking mug versus a sham mug.

Effect of Neck Rotation With Flexion on Ultrasonographic Optic Nerve Sheath Diameter in Patients Undergoing Elective Craniotomy.

Background Extreme neck positioning to facilitate craniotomy can result in impaired venous drainage from the brain and a subsequent rise in increased intracranial pressure (ICP). The effects of varied neck positioning intraoperatively on ultrasonographic optic nerve sheath diameter (USG-ONSD) are still unexplored. This study aims to quantify the angle of neck rotation and flexion that can cause a significant increase in USG-ONSD in patients undergoing elective craniotomy. Methods A total of 100 patients were recruited in this non-randomized study and equally divided into two groups. In one group, patients with neck rotation ≤30 degrees and in another group, patients with neck rotation >30 degrees with varying degrees of neck flexion were included. The average of three USG-ONSD measurements in both eyes was obtained and compared in both groups at baseline, after positioning, and at the end of the surgery after making the neck neutral. Results The results of 100 recruited patients were analyzed. All the patients had neck flexion in the range of40° to 45°, whereas the neck rotation ranged from 10° to 45°. The USG-ONSD of both eyes changed significantly from baseline to post-positioning time point in patients with neck rotation >30° (right eye p=0.038, left eye p=0.04) when compared to neck rotation ≤30°. There was no significant change in USG-ONSD from baseline to the postoperative time point after making the neck neutral (right eye p=0.245, left eye p=0.850) in both groups. Conclusions This study demonstrates that USG-ONSD, a surrogate measure of ICP, increased significantly after neck flexion with rotation >30° in neurosurgical patients. However, USG-ONSD becomes comparable to baseline after putting the patient's neck in a neutral position after surgery.

Use of Soft Cervical Collar Improves Surgeon Ergonomics During Simulated Otologic Surgery.

To determine whether surgeon use of a soft cervical collar during endoscopic and microscopic otologic surgery is feasible and impacts surgeon ergonomics as measured by inertial sensors. Prospective crossover trial. US-based otolaryngology training program. Otolaryngology residents and fellows. Therapeutic-use of a soft cervical collar during simulated otologic surgery. Time spent in high-risk angles of neck and back flexion and extension; average angle of neck flexion, extension, rotation, and lateral bending; validated assessment of neck pain; average daily phone use. Fifteen subjects met criteria for inclusion. Ten of 15 (67%) were male. Seven of 15 (47%) were postgraduate year 1-2. Seven of 15 (47%) reported a history of neck pain. None reported prior spinal steroid injections or surgery. Across all subjects, use of the soft cervical collar significantly reduced time spent in high-risk angles of neck flexion/extension during both endoscopic (56% vs. 35%, p < 0.05) and microscopic (60% vs. 32%, p < 0.05) otologic surgery. There was no effect on back flexion or extension. There was no difference in time spent in high-risk neck or back angles between endoscopic and microscopic surgery. Average angles of neck or back flexion, extension, lateral bending, and rotation were not significantly different for subgroups with more operative experience, increased phone use, perception of good posture, or history of neck pain. Use of a soft cervical collar during simulated otologic surgery significantly reduced time spent in high-risk neck positions. These data support feasibility of soft collar use during otologic surgery and hold promise for reduction in the high rates of neck pain reported by neurotologists. Improving surgeon ergonomics for otologic surgery. To identify a therapeutic intervention to mitigate neck pain in surgeons caused by assumption of high-risk cervical neck flexion and extension. To demonstrate that use of a readily available soft cervical collar reduces risk of neck pain in otologic surgeons. II. Exempt.

Effect of istradefylline on postural abnormalities in patients with Parkinson's disease: An association study of baseline postural angle measurements with changes in Unified Dystonia Rating Scale total score

In our previous study, istradefylline treatment in patients with Parkinson's disease (PD) improved postural abnormalities (PAs), as seen from a decrease in the mean Unified Dystonia Rating Scale (UDRS) total score from week 0 to week 24. A subgroup analysis based on baseline clinical characteristics investigated the association between improvement in the UDRS total score and istradefylline treatment. However, the association between an objective assessment of PAs and improvement in the UDRS total score is unclear. This ad hoc analysis investigated the association between improvement in the UDRS total score after istradefylline treatment and baseline trunk and neck angles, objective assessments of PAs, measured from patients' photographs taken in the previous study. The patients (n = 31) were stratified into groups based on the trunk forward flexion angle (TFFA), trunk lateral flexion angle (TLFA), and neck flexion angle (NFA) values at baseline. From week 0 to week 24, significant improvements in the UDRS total score were found in median percent change (−8.33% [interquartile range: −43.97, 0.00], P = 0.039) in patients with equal to or above the median TFFA values, and in median change (−‍1.50 [−9.25, 0.00], P = 0.015) and median percent change (−13.33% [−50.47, 0.00], P = 0.009) in patients with equal to or above the median TLFA values. Patients with more advanced PAs showed more consistent improvements in the UDRS total score with istradefylline. Baseline TFFA and TLFA values, which are objective values, may be useful to assess the istradefylline effectiveness in patients with PD and PAs.

Novel Fiber-Based Padding Materials for Football Helmets

An experimental study is performed to determine the head mechanics of American football helmets equipped with novel fiber energy absorbing material (FEAM). FEAM-based padding materials have substrates of textile fabrics and foam made with nylon fibers using electro-static flocking process. Both linear and angular accelerations of the sport helmets are determined under impact loads using a custom-built linear impactor and instrumented head. The effectiveness of padding materials and vinyl nitrile (VN) foam for impact loads on six different head positions that simulate two helmeted sport athletes in real-time helmet-to-helmet strike/impact is investigated. A high-speed camera is used to record and track neck flexion angles and compare them with pad effectiveness to better understand the head kinematics of struck players at three different impact speeds (6 m/s, 8 m/s, and 10 m/s). At impact speed of 6 m/s and 8 m/s, the FEAM-based padding material of 60 denier fibers showed superior resistance for angular acceleration. Although novel pads of VN foam flocked with 60 denier fibers outperformed with lowest linear acceleration for most of the head positions at low impact speed of 6 m/s, VN foam with no fibers demonstrated excellent performance for linear acceleration at other two speeds.

Biomechanical Load of Neck and Lumbar Joints in Open-Surgery Training.

The prevalence of musculoskeletal symptoms (MSS) like neck and back pain is high among open-surgery surgeons. Prolonged working in the same posture and unfavourable postures are biomechanical risk factors for developing MSS. Ergonomic devices such as exoskeletons are possible solutions that can reduce muscle and joint load. To design effective exoskeletons for surgeons, one needs to quantify which neck and trunk postures are seen and how much support during actual surgery is required. Hence, this study aimed to establish the biomechanical profile of neck and trunk postures and neck and lumbar joint loads during open surgery (training). Eight surgical trainees volunteered to participate in this research. Neck and trunk segment orientations were recorded using an inertial measurement unit (IMU) system during open surgery (training). Neck and lumbar joint kinematics, joint moments and compression forces were computed using OpenSim modelling software and a musculoskeletal model. Histograms were used to illustrate the joint angle and load distribution of the neck and lumbar joints over time. During open surgery, the neck flexion angle was 71.6% of the total duration in the range of 10~40 degrees, and lumbar flexion was 68.9% of the duration in the range of 10~30 degrees. The normalized neck and lumbar flexion moments were 53.8% and 35.5% of the time in the range of 0.04~0.06 Nm/kg and 0.4~0.6 Nm/kg, respectively. Furthermore, the neck and lumbar compression forces were 32.9% and 38.2% of the time in the range of 2.0~2.5 N/kg and 15~20 N/kg, respectively. In contrast to exoskeletons used for heavy lifting tasks, exoskeletons designed for surgeons exhibit lower support torque requirements while additional degrees of freedom (DOF) are needed to accommodate combinations of neck and trunk postures.

Musculoskeletal demands in microsurgery-an explorative study comparing the ergonomics of microscope and 3D exoscope.

To assess neurosurgeons' physical demands and investigate ergonomic aspects when using microsurgical visualization devices. Six neurosurgeons performed micro-surgical procedures on cadaveric specimens using the prototype of a digital 3D exoscope system (Aeos®, Aesculap, Tuttlingen, Germany) and a standard operating microscope (Pentero 900, Zeiss, Oberkochen, Germany) at two different patient positions (semisitting (SS), supine (SP)). The activities of the bilateral upper trapezius (UTM), anterior deltoid (ADM), and lumbar erector spinae (LEM) muscles were recorded using bipolar surface electromyography and neck flexion, arm abduction, and arm anteversion angles by gravimetrical posture sensors. Perceived discomfort frequency was assessed and subjects compared the two systems in terms of usability, posture, physical and mental demands, and working precision. Using the exoscope led to reduced ADM activity and increased UTM and LEM activity during SS position. The neck was extended when using the exoscope system with lower arm anteversion and abduction angles during the SS position. Subjects reported discomfort at the shoulder-neck area less frequently and lower physical demands when using the Aeos®. However, mental demands were slightly higher and two subjects reported lower working precision. The exoscope system has the potential to reduce the activity of the ADM by changing surgeons arm posture which may be accompanied by less discomfort in the shoulder-neck area. However, dependent on the applied patient position higher muscle activities could occur in the UTM and LEM.

Evaluation of surface electromyography of selected neck muscles during the whiplash mechanism in aware and unaware conditions due to safe punching in kickboxing

BackgroundKickboxing is considered as a combat sport in progress, in which injuries are frequent and significant, and close injury monitoring is highly recommended. Sports injuries to the head and neck are estimated to cause 70% deaths and 20% permanent disabilities although they are much less common than those to the limbs. Whiplash mechanism involves the rapid extension (opening) and flexion (bending) of neck. The purpose of the current study was to investigate the electromyographic activity of selected muscles in the whiplash mechanism in aware and unaware conditions of the safe punching in kickboxing so that we can design special exercises.MethodIn the present study, 24 male kickboxing athletes aged 18–40 years were selected based on a purposive sampling method. The surface electromyography (EMG) signals of muscles were recorded with and without awareness of safe punching by using a nine-channel wireless EMG device. Additionally, a nine-channel 3D inertial measurement unit (IMU, wireless,) was utilized to determine the acceleration, kinematics, and angular velocity of the subjects’ head. The statistical dependent t-test was applied to compare the EMG activity of each muscle, as well as its participation ratio.ResultsThe results of statistical analysis represented a significant increase in the EMG activity of sternocleidomastoid (p = 0.001), upper trapezius (p = 0.001) and cervical erector spinae muscles (p = 0.001), as well as the neck extension and flexion angles between the athletes aware (open eyes) and unaware (closed eyes) of the safe punching.ConclusionIn this study, the EMG activity of the sternocleidomastoid, upper trapezius, and cervical erector spine muscles in the aware condition was significantly different from the activity under unaware condition. In fact, the intended muscles exhibited significantly different behaviors in preventing extension and flexion in the two conditions.

목 굴곡 각도에 따른 스마트폰 사용이 목세움근과 위등세모근의 근피로도에 미치는 영향

This study investigated the effect of smartphone use by smartphone users" various angles on neck fatigue after using smartphone. Fifteen participants playing the game tasks for 20 min and Neck muscle fatigue was measured by extension the neck for 30 seconds in a supine position before and after using the smartphone at various neck flexion angles. At each neck flexion angle, there was no difference in the degree of muscle fatigue of the Upper Trapezius(UT) when extension of the neck between groups and within the group at both before and after using the smartphone. In the Cervical Erector Spinae(CES), there was no difference in fatigue at each neck flexion angle, but the difference in muscle fatigue within the groups was confirmed that the left side had more muscle fatigue after using the smartphone than before using the smartphone at a 45° flexion angle. In conclusion, smartphone users should be instructed not to adopt a neck flexion angle of 45° during smartphone use, as there is a link between these neck flexion angle ranges and increased CES muscle fatigue. Practitioner summary: This study proved that we should try to avoid a 45° neck flexion angle when using a smartphone.

Finite element analysis of the cervical spine and soft tissue of the neck at different flexion angles

Aim: This study aims to investigate the impact of von Mises stress distribution on the cervical spine and soft tissue of the neck at different flexion angles of 0°, 15°, 30°, 45°, and 60°. Materials and Methods: Finite element analysis of the neck's cervical spine and soft tissue was performed separately in Ansys Discovery Live software, a possible approach for simulating the mechanical behavior of the neck. Three-dimensional (3D) models were created in 3D Max software and static structural analyses of soft tissues were performed in ANSYS by using the Finite Element Method. The maximum stress distributions of the cervical spine in cervical vertebra bodies at different flexion angles were analyzed at the lowest and highest stress values of 0° and 30°, respectively. For the intervertebral contact surfaces, the lowest and highest stress values were determined at 0° and 45°, respectively. Results: The value of stress showed a linear increase with increasing flexion angles in the soft tissue of the neck. The observation that the stress values obtained at different flexion angles were arbitrarily in either positive or negative directions when compared to the upright posture suggests that the effect of neck flexion on stress distribution in the cervical spine is complex and multifactorial. The change in stress values in the soft tissue of the neck was always positive and linear with increasing flexion angles. Conclusion: People who work with technological devices are prone to a musculoskeletal disorder associated with forward flexion of the neck, and individuals are encouraged to adopt a neck flexion angle between 0° and 15°. This finding could help guide the development of strategies to reduce the risk of neck injury or damage in different postures.

Measurement Issue in Antecollis.

Background:Antecollis is defined as an involuntary forward flexion of the neck. Previous reports have measured the neck flexion angles based on the line perpendicular to the ground. This led to an inflation of the neck flexion angles in patients who had combined forward truncal flexions, especially upper camptocormia.Methods:We examined the neck flexion angles and the upper camptocormia angle in the published photographs of antecollis. MEDLINE search was conducted using the following search terms: antecollis OR anterocollis. Lateral-view photographs of patients diagnosed with antecollis were collected. Neck flexion angles were measured with the classic ‘perpendicular method’ and the ‘antecollis method’ we developed.Results:Nine patient photographs were identified. While antecollis was the only described postural abnormality in eight cases, these patients exhibited upper camptocormia angles of 45° or larger. The mean neck flexion angle measured with the antecollis method was 49.7°, while the perpendicular method yielded 103.4°.Discussion:Upper camptocormia should be considered in the evaluation of antecollis. We propose a new method to measure neck flexion in relation to the torso, instead of the vertical line.

Effects of cervicothoracic postures on the stiffness of trapezius muscles.

The purposes of this study were to (1) examine the effects of different cervicothoracic postures on the stiffness of trapezius muscles and (2) compare the stiffness of the dominant and non-dominant trapezius muscles. Twenty-one healthy participants joined in this project. After maintaining different cervicothoracic postures for 2min, MyotonPRO was used to measure the stiffness of the trapezius. The results showed that (1) the stiffness of trapezius muscles was significantly affected by different cervicothoracic postures. With the increase of neck flexion angle, the stiffness of the trapezius muscles increased (p < 0.05). The muscle stiffness of upper back relaxed was higher than that of upper back upright (p < 0.05). (2) The trapezius muscles on the non-dominant side were stiffer than that on the dominant side (p < 0.05). Poor cervicothoracic postures will increase the stiffness of upper, middle and lower trapezius muscles. Keeping the neck and upper back upright will keep the muscle stiffness at a low level, so as to reduce the occurrence of neck and shoulder fatigue and pain.

Basilar Invagination: A Tilt of the Foramen Magnum

Congenital basilar invagination (BI) is a craniocervical deformity marked by odontoid prolapse into the skull base. The foramen magnum angle (FMA), which is formed by the Chamberlain's line and McRae's line, has not been fully studied. The study aimed to investigate the FMA and its relationship with other craniocervical parameters. Participants were divided into control, type A BI, and type B BI groups. Parameters included Chamberlain line violation, atlantodental interval, clivus height, clivus anteroposterior dimension, FMA, basal angle, clivo-axial angle, head and neck flexion angle, Boogard's angle, and subaxial cervical spine lordosis angle. A comparison of these parameters among the 3 groups and correlation analysis between FMA and other parameters were performed. The significance level was set at P < 0.05. A total of 111 controls, 111 type A BI patients, and 62 type B BI patients were enrolled. The FMAs in the control, type A BI, and type B BI groups were 6.21° (3.67°, 8.71°), 22.16° ± 6.61°, and 22.39° (17.27°, 31.08°), respectively. Correlation analysis revealed correlations between the FMA and other variables. In the 2 BI subgroups, FMA was significantly correlated with Chamberlain line violation, clivus height, clivus anteroposterior dimension, basal angle, clivo-axial angle, and Boogard's angle. The FMA in patients with BI was approximately 22° and approximately 6° in controls, indicating that the foramen magnum in BI had a greater tilt. As a pathological condition, FMA can reflect the degree of BI. Clivus hypogenesis is a reason for the excessive tilt of the FM.

A Systematic Review on the Biomechanics of Breakfall Technique (Ukemi) in Relation to Injury in Judo within the Adult Judoka Population.

Objectives: To investigate the biomechanics of Ukemi in relation to head and neck injury in adult judokas with varying skill sets. Design: Narrative systematic review. Methods: An extensive literature search was performed using PubMed, Google Scholar, Science direct and EMBASE from inception to April 2021. Studies were included if they: (1) reported biomechanical analysis of judo throws and Ukemi; (2) were on adult judoka populations; (3) discussed injury related to judo technique. The included studies were assessed for risk of bias using a five-part modified STROBE checklist. A narrative synthesis was performed due to the heterogeneity of included studies. Results: 173 titles and abstracts were screened with 16 studies (158 judokas, 9 of which were female) included. All studies used 3D biomechanical analysis to assess Ukemi. Ukemi implementation produced reduced kinematic data in comparison to direct occipital contact, which was always below the injury threshold. Analysis of lower limb and trunk kinematics revealed variances in Ukemi between novice and experienced judoka. Whilst no significant differences were seen in neck flexion angles, hip, knee and trunk angle time plots revealed greater extension angles in experienced judokas. Conclusions: Ukemi is essential in preventing head and neck injuries; however, technique differs between experienced and novice judoka. Larger flexion angles of the hip, knee and trunk are seen in novice judoka, which correlate with increased kinematic data. The association of greater neck muscle strength with improved Ukemi is weak. However, a negative correlation was established between fatigue and breakfall skill by one study.

Effects of head flexion posture in patients with dysphagia.

The chin-down posture is often used as a compensatory manoeuvre for patients with dysphagia. This posture presumably involves flexion of the head and/or neck, but this is not clearly defined. This study aimed to assess the effects of head flexion posture in a retrospective study of videofluoroscopic examination of swallowing (VF). A total of 73 patients who underwent VF both with and without head flexion posture in the lateral projection were included in the analysis. The head and neck angles at the initiation of the swallowing reflex, penetration-aspiration scale (PAS), nasopharyngeal closure time, stage transition duration, duration of laryngeal closure, time from swallowing reflex to laryngeal closure and to the opening of upper oesophageal sphincter (UES), duration of UES opening, location of the bolus leading edge at swallowing reflex, and bolus transition time were evaluated. The head flexion angle increased (p<0.001), but the neck flexion angle did not change in the head flexion posture. Moreover, PAS improved (p<0.001), aspiration was reduced (p<0.001), the time between the swallowing reflex and the onset of laryngeal closure was shortened (p=0.006), and the leading edge of the bolus at swallowing reflex became shallower (p=0.004) in the head flexion posture. Other parameters did not significantly change. The head flexion posture resulted in earlier laryngeal closure and a shallower position of the leading bolus edge at swallowing reflex, resulting in PAS improvement and decreased aspiration.

The effect of disruption of the repaired nuchal ligament on clinical outcomes after posterior cervical spine surgery: A retrospective comparative study.

This study aimed to investigate whether disruption of the repaired nuchal ligament (NL) affects clinical outcomes following posterior cervical spine surgery. This retrospective study included 101 patients (65 males, 36 females) who underwent posterior cervical spine surgery, 69 of whom received laminoplasty (LP), and 32 posterior decompression and fusion (PDF). The NL was split during the surgical approach and repaired at the time of wound closure. The frequency and spinal levels of NL disruption at one month, six months, and one year postoperatively were evaluated on mid-sagittal and axial magnetic resonance images. Postoperative axial symptoms, Neck Disability Index, T1 slope, flexion and extension angle, C2-C7 lordotic angle, and decrease rate of C2-C7 range of motion (ROM) were examined at six months and/or one year postoperatively. Based on the NL disruption levels, the patients were divided into the upper group (C2-C5), lower group (C6-T1), and non-disruption group. Although the lower group contained patients with NL disruption (10%) after LP at final follow-up, all PDF patients belonged to the non-disruption group. For the LP patients, the postoperative axial symptoms, Neck Disability Index, T1 slope, flexion and extension angle, and C2-C7 lordotic angle did not significantly differ between the lower and non-disruption groups; however, the rate of C2-C7 ROM decrease in the lower group (48%) was considerably larger than that in the non-disruption group (33%) after LP. Evidence from this study has shown that postoperative disruption of the repaired NL has no significant effect on postoperative axial symptoms and C2-C7 alignment, but it can affect the rate of decrease in C2-C7 ROM after LP. Level III, Therapeutic Study.

Effects of smartphone screen viewing duration and body position on head and neck posture in elementary school children.

Electronic media have become integral parts of modern life, in which prolonged screen viewing time (SVT) by children is nearly unavoidable. Prolonged use of smartphones could lead to musculoskeletal problems. To investigate the effect of SVT on head and neck posture during and after using smartphones for various periods of time in either standing or sitting postures. This observational study included 34 male children aged 5-12 years who were assigned to one of two groups based on average smartphone use duration per day: group A comprised 18 children averaging > 4 hours per day (h/day) of smartphone use, and group B comprised 16 children with < 4 h/day of smartphone use. The children's postures were photographed in standing and sitting positions while using a smartphone and 30 min after ceasing smartphone use. The head flexion, neck flexion, gaze, and craniocervical angles were measured using the software program Kinovea. Significant increases were found in head flexion, neck flexion, and gaze angles. Furthermore, both groups saw a significant decrease in craniocervical angle when sitting compared to when standing, both during and 30 min after smartphone use. The head flexion, neck flexion, and gaze angles of group A were significantly higher than those of group B, and the craniocervical angle of group A was significantly lower than that of group B in both postures (p< 0.05). SVT is associated with increased neck and head flexion posture in children, especially in a sitting position.

Head and Upper Limb Motor Control in Elementary School Children with Handwriting Difficulties

ABSTRACT Children with suspected developmental disabilities often have handwriting difficulties and show problems with motor control of the head and upper limbs, but it has not been examined in detail. The purpose of this study was to examine the characteristics of motor control in children with suspected developmental disabilities and writing difficulties. Nineteen right-handed males who were receiving support in the resource room for handwriting difficulties (SDD group) were compared with 17 right-handed age-matched male controls. Both groups completed two handwriting tasks. The main measures were jerk and changes in joint angle, which were measured by a 3D motion analysis system. The SDD group had significantly higher mean values of jerk in the head, forearms, and hands and significantly greater changes in the joint angle of neck flexion in both handwriting tasks compared to the control group. Children with suspected developmental disabilities and handwriting difficulties had less smooth forearm movements and greater fixed head movements.

Exploring whole-body kinematics when eating real foods with the dominant hand in healthy adults.

Despite the importance of eating movements to the rehabilitation of neurological patients, information regarding the normal kinematics of eating in a realistic setting is limited. We aimed to quantify whole-body three-dimensional kinematics among healthy individuals by assessing movement patterns in defined phases while eating real food with the dominant hand in a seated position. Our cross-sectional study included 45 healthy, right-hand dominant individuals with a mean age of 27.3 ± 5.1 years. Whole-body kinematics (joint angles of the upper limb, hip, neck, and trunk) were captured using an inertial sensor motion system. The eating motion was divided into four phases for analysis: reaching, spooning, transport, and mouth. The mean joint angles were compared among the phases with Friedman's analysis of variance. The maximum angles through all eating phases were 129.0° of elbow flexion, 32.4° of wrist extension, 50.4° of hip flexion, 6.8° of hip abduction, and 0.2° of hip rotation. The mean shoulder, elbow, and hip joint flexion angles were largest in the mouth phase, with the smallest being the neck flexion angle. By contrast, in the spooning phase, the shoulder, elbow, and hip flexion were the smallest, with the largest being the neck flexion angle. These angles were significantly different between the mouth and spooning phases (p < 0.008, Bonferroni post hoc correction). Our results revealed that characteristic whole-body movements correspond to each phase of realistic eating in healthy individuals. This study provides useful kinematic data regarding normal eating movements, which may inform whole-body positioning and movement, improve the assessment of eating abilities in clinical settings, and provide a basis for future studies.