Virkni sternocleidomastoid vöðva í tveimur þungaberandi stöðum

Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn View/OpenWork-related neck and upper limb disorders (WRUNLD) are a negative factor of increased computer use. Neck pain has been associated with neck and head posture but according to the literature the outcome is conflicting. The purpose of this study was to investigate the muscular activity in the sternocleidomastoid (SCM) muscles during sitting in two different cranio-cervical postures (CCP’s) in a standard computer environment using electromyography (EMG). The muscular activity was measured during 5 minutes period, twice with the head held in a resting posture (RHP) and once after being placed, by the author, in a neutral head posture (NHP) as defined by Kendall et al. (2005). Linear excursion measurement device (LEMD) was used to determine the differences between the resting and neutral head postures. Twenty-four students from the University of Birmingham (aged 19-31) responded to an e-mail request for volunteers and fulfilled the inclusion criteria. The study was single-blinded, two-tailed, using the same subject design with A-A-B repeated measurements where A- represents the resting and B- the neutral head posture. The participants attended a laboratory room for measurements where the total procedure time was approximately 30 minutes. Root-mean-square (RMS) values over one minute of the EMG signals were calculated for data analysis. The paired t-test was used for statistical analysis using SPSS (version 15). The results showed no significant difference (P=0.08) in muscular activity in the sternocleidomastoid muscles when sitting with the head in resting or neutral head postures. The LEMD outcome showed that the participants’ resting head postures deviated significantly (P<0.001) from the neutral head posture. The findings suggest increased activity in the SCM muscles in the neutral head posture compared with the resting one. It also shows that neutral head posture is unfamiliar among young individuals working on computers.Óþægindi frá stoðkerfinu eru algeng hjá einstaklingum sem vinna við tölvur. 24,48,49,55,56 Rannsóknir hafa sýnt fram á að bæði vinnustellingar og vinnuumhverfi geta verið undirliggjandi þættir í þróun einkenna fyrir háls- og herðasvæði.1,7,24,25,28,40,48,49,50,56 Aðferðir til að mæla virkni hálsvöðva eru ólíkar54 sem og aðferðir við mælingar á höfuð-hálsstöðu (cranio-cervical posture) þannig að samanburður er oft erfiður á milli rannsókna.29,41 Sú aðferð sem mest hefur verið notuð til mælingar á virkni beygjuvöðva háls er „höfuð-háls beygju prófið” (cranio-cervical flexion test) með aðstoð vöðvarafrits (EMG).4,16,17,31,33,34,42,52,57 „Höfuð-háls beygju prófið“ mælir hins vegar ekki virkni hálsvöðva í þungaberandi stöðu við starfræna færni. Sama má segja um mælingar á höfuð-háls stöðu sem enn hafa ekki verið staðlaðar fyrir þungaberandi stöðu. Fáar rannsóknir hafa mælt virkni beygjuvöðva háls í þungaberandi stöðu og engin „randomized controlled trials“ (RTC) (slembuð samanburðarrannsókn) hefur verið birt. Enn hefur ekki verið fundin sönnun fyrir sambandi milli höfuð-hálsstöðu og hreyfistjórnunarkerfisins (motor control).49 Rannsóknir hafa sýnt mismunandi niðurstöður varðandi hlutverk höfuð-hálsstöðu við verkjavandamál í hálsi og herðum.29,41 M. sternocleidomastoid hefur lítið verið rannsakaður í mismunandi höfuð-hálsstöðum í þungaberandi stöðu. Hlutverk m. sternocleidomastoid er tvíþætt, réttir (neck extensor) í atlanto-occipital lið en beygir (neck flexor) í neðri hluta hálsins.8,18,26 Tilgangur rannsóknarinnar var að mæla virkni í m. sternocleidomastoid hjá þátttakendum í sitjandi stöðu með höfuð í hvíldarstöðu (resting head posture) og í miðstöðu (neutral head posture)

The Cambridge Face Tracker: Accurate, Low Cost Measurement of Head Posture Using Computer Vision and Face Recognition Software.

PURPOSE: We validate a video-based method of head posture measurement. METHODS: The Cambridge Face Tracker uses neural networks (constrained local neural fields) to recognize facial features in video. The relative position of these facial features is used to calculate head posture. First, we assess the accuracy of this approach against videos in three research databases where each frame is tagged with a precisely measured head posture. Second, we compare our method to a commercially available mechanical device, the Cervical Range of Motion device: four subjects each adopted 43 distinct head postures that were measured using both methods. RESULTS: The Cambridge Face Tracker achieved confident facial recognition in 92% of the approximately 38,000 frames of video from the three databases. The respective mean error in absolute head posture was 3.34°, 3.86°, and 2.81°, with a median error of 1.97°, 2.16°, and 1.96°. The accuracy decreased with more extreme head posture. Comparing The Cambridge Face Tracker to the Cervical Range of Motion Device gave correlation coefficients of 0.99 (P < 0.0001), 0.96 (P < 0.0001), and 0.99 (P < 0.0001) for yaw, pitch, and roll, respectively. CONCLUSIONS: The Cambridge Face Tracker performs well under real-world conditions and within the range of normally-encountered head posture. It allows useful quantification of head posture in real time or from precaptured video. Its performance is similar to that of a clinically validated mechanical device. It has significant advantages over other approaches in that subjects do not need to wear any apparatus, and it requires only low cost, easy-to-setup consumer electronics. TRANSLATIONAL RELEVANCE: Noncontact assessment of head posture allows more complete clinical assessment of patients, and could benefit surgical planning in future

Differential postural effects of plantar-flexor muscles fatigue under normal, altered and improved vestibular and neck somatosensory conditions

The aim of the present study was to assess the effects of plantar-flexor muscles fatigue on postural control during quiet standing under normal, altered and improved vestibular and neck somatosensory conditions. To address this objective, young male university students were asked to stand upright as still as possible with their eyes closed in two conditions of No Fatigue and Fatigue of the plantar-flexor muscles. In Experiment 1 (n=15), the postural task was executed in two Neutral head and Head tilted backward postures, recognized to degrade vestibular and neck somatosensory information. In Experiment 2 (n=15), the postural task was executed in two conditions of No tactile and Tactile stimulation of the neck provided by the application of strips of adhesive bandage to the skin over and around the neck. Centre of foot pressure displacements were recorded using a force platform. Results showed that (1) the Fatigue condition yielded increased CoP displacements relative to the No Fatigue condition (Experiment 1 and Experiment 2), (2) this destabilizing effect was more accentuated in the Head tilted backward posture than Neutral head posture (Experiment 1) and (3) this destabilizing effect was less accentuated in the condition of Tactile stimulation than that of No tactile stimulation of the neck (Experiment 2). In the context of the multisensory control of balance, these results suggest an increased reliance on vestibular and neck somatosensory information for controlling posture during quiet standing in condition of altered ankle neuromuscular function

Deep and Superficial Cervical Flexor Muscles Strength in Female Students with Forward Head Posture Compared to Normal Group Using Electromyography and Pressure Bio- Feedback Device

Abstract: Background & Aims: Forward head posture deformity is a disorder in head weight balance condition leading to some alterations in cervical muscles, strength. This research aimed to determine the strength of deep and superficial cervical flexor muscles in female students with forward head posture compared to the normal group. Methods: From the total of 724 female students in Shahid Bahonar University taking physical education I course, 60 students were enrolled into the two equal groups of with and without forward head posture. For selecting subjects, Posture screen test, New York test and lateral photography in stand position were used. Pressure Biofeedback device was applied to investigate the strength of cervical muscles during two craniocervical flexion test (CCFT) and combination test. To ensure proper performance of tests, Surface Electromyography was used. Results: The two groups showed significant difference in deep cervical muscles strengths (P=0.002), while there was no significant difference between the two groups in superficial flexor muscles strength (P=0.803). Conclusion: Since activation of superficial cervical flexor muscles leads to deep cervical flexor muscles inactivity, designing training programs involving just deep flexor muscles seems to be essential in individuals with forward head posture deformity. Keywords: Neck muscles, Forward head posture, Craniovertebral angle, Electromyography, Pressure Bio-feedback devic

Head and scapular posture in flutists: a pilot controlled study

Instrumental practice which requires asymmetrical postures might, in the long term, potentiate musculoskeletal disorders and lead to pain. This, in turn, may have a negative impact on musical performance quality. Thus, the assessment of postural deviations among musicians is of the outmost importance in instrumental pedagogy. This study aims to compare the head and scapular posture of flutists with different levels of expertise and a control group of singers. Results suggest that flutists have a significantly more forward head posture than singers. No significant differences were found for any other head or scapular posture measurement. Contrary to what was hypothesized, years of instrumental practice did not contribute to a more asymmetrical posture.head posture; scapular posture; instrumental practice; flutists

Inter and intra-rater reliability of head posture assessment through observation

The purpose of this study is to assess inter and intra-rater reliability of head posture (HP) assessment through observation

Effects of experimental insoles on body posture, mandibular kinematics and masticatory muscles activity. A pilot study in healthy volunteers

BACKGROUND: It has been hypothesized that different plantar sensory inputs could influence the whole body posture and dental occlusion but there is a lack of evidence on this possible association. OBJECTIVES: To investigate the effects of experimental insoles redistributing plantar pressure on body posture, mandibular kinematics and electromyographic (EMG) activity of masticatory muscles on healthy subjects. METHODS: A pilot study was conducted on 19 healthy volunteers that wore custom-made insoles normalizing the plantar pressure distribution for 2 weeks. Body posture parameters were measured by means of an optoelectronic stereophotogrammetric analysis; mandibular kinematics was analyzed by means of gothic arch tracings; superficial EMG activity of head and neck muscles was performed. Measurements were carried out 10 days before the insertion of the insoles, immediately before the insertion, the day after, 7 and 14 days after, in four different exteroceptive conditions. RESULTS: The outcomes of the present study show that insoles do not modify significantly over time the parameters of body posture, SEMG activity of head and neck muscles and mandibular kinematics. CONCLUSIONS: In this pilot study the experimental insoles did not significantly influence the body posture, the mandibular kinematics and the activity of masticatory muscles during a 14-day follow up perio

Head posture detection for measuring preschoolers concentration

Several decades of research clearly demonstrate that high-quality, developmentally appropriate, early childhood programs, produce short and long-term positive effects on children’s cognitive and social development. Research with the Leuven Involvement Scale has shown that the levels of children’s involvement are a predictor of quality of learning. An involved child gets extremely fascinated and absorbed by the activity he is performing. There are several indicators that can be used to assess children involvement, such as concentration, energy, com- plexity and creativity, facial expression and posture, persistence, precision, reaction time, language and satisfaction. Some of these indicators require that the teacher pay attention to posture, measure and record the time that the child is facing a specific activity. Head posture usually indicates the focus of attention, since it coincides with the gaze direction, the direction and focus of a person’s eyes. This task is complex and requires several observations, on many children, distributed through the day. Usually, this is performed with a video recorder to help the teacher to evaluate the observation. The work described in this paper focus on how modern image processing technology can provide a valu- able aid to kindergarten teachers, helping them in the task of registering observations. In this context, head posture is automatically detected and measured, and time is recorded. Although easy for a human to interpret the orientation and movement of the human head, it is a challenge to computers. Of course there is always subjectivity in this kind of observation, but we hope that this tool can contribute to help teachers to make informed and critical judgments about the quality of teaching and learning they offer

Age-related differences in head posture between patients with neck pain and pain-free individuals

Head posture and neck pain of chronic nontraumatic origin: a comparison between patients and pain-free persons.SFRH/BD/30735/20