Comfort, stability and body posture in wheelchair cushions: a preliminary study with able bodied subjects

Long term wheelchair usage has been related to a number of problems, among which pressure ulcers are one of most concern. The design of wheelchair seat cushions has been of increasing interest among researchers, as it can influence seat interface pressure and user's comfort. The aim of this study was to investigate the subjects' perception comfort, stability and body posture of six different commercially available wheelchair cushions. The evaluation was through a questionnaire, where the subjects rate their perceptions on a ten point visual analog scale after staying seated in the cushion for two minutes. The results shows that the Roho^TM aircell cushion was preferred by the users, while the least preferred one was the water cushion. Individuals' subjective perceptions may compliment objective data on seat interface pressure, thus contributing to a more complete view of the users' experience during wheelchair cushion usage.

Forças manuais e o design de produtos: uma revisão

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Inter-rater reliability of the evaluation of muscular chains associated with posture alterations in scoliosis

Background: In the Global postural re-education (GPR) evaluation, posture alterations are associated with anterior or posterior muscular chain impairments. Our goal was to assess the reliability of the GPR muscular chain evaluation. Methods: Design: Inter-rater reliability study. Fifty physical therapists (PTs) and two experts trained in GPR assessed the standing posture from photographs of five youths with idiopathic scoliosis using a posture analysis grid with 23 posture indices (PI). The PTs and experts indicated the muscular chain associated with posture alterations. The PTs were also divided into three groups according to their experience in GPR. Experts' results (after consensus) were used to verify agreement between PTs and experts for muscular chain and posture assessments. We used Kappa coefficients (K) and the percentage of agreement (%A) to assess inter-rater reliability and intra-class coefficients (ICC) for determining agreement between PTs and experts. Results: For the muscular chain evaluation, reliability was moderate to substantial for 12 PI for the PTs (% A: 56 to 82; K: 0.42 to 0.76) and perfect for 19 PI for the experts. For posture assessment, reliability was moderate to substantial for 12 PI for the PTs (% A > 60%; K: 0.42 to 0.75) and moderate to perfect for 18 PI for the experts (% A: 80 to 100; K: 0.55 to 1.00). The agreement between PTs and experts was good for most muscular chain evaluations (18 PI; ICC: 0.82 to 0.99) and PI (19 PI; ICC: 0.78 to 1.00). Conclusions: The GPR muscular chain evaluation has good reliability for most posture indices. GPR evaluation should help guide physical therapists in targeting affected muscles for treatment of abnormal posture patterns.

Cortical activation during executed, imagined, observed, and passive wrist movements in healthy volunteers and stroke patients

Motor imagery, passive movement, and movement observation have been suggested to activate the sensorimotor system without overt movement. The present study investigated these three covert movement modes together with overt movement in a within-subject design to allow for a fine-grained comparison of their abilities in activating the sensorimotor system, i.e. premotor, primary motor, and somatosensory cortices. For this, 21 healthy volunteers underwent functional magnetic resonance imaging (fMRI). In addition we explored the abilities of the different covert movement modes in activating the sensorimotor system in a pilot study of 5 stroke patients suffering from chronic severe hemiparesis. Results demonstrated that while all covert movement modes activated sensorimotor areas, there were profound differences between modes and between healthy volunteers and patients. In healthy volunteers, the pattern of neural activation in overt execution was best resembled by passive movement, followed by motor imagery, and lastly by movement observation. In patients, attempted overt execution was best resembled by motor imagery, followed by passive movement and lastly by movement observation. Our results indicate that for severely hemiparetic stroke patients motor imagery may be the preferred way to activate the sensorimotor system without overt behavior. In addition, the clear differences between the covert movement modes point to the need for within-subject comparisons. (C) 2012 Elsevier Inc. All rights reserved.

ANALYSIS OF THE BALANCE CONTROL IN SURFERS DURING THE ERECT POSTURE

Background: Surfing is a sport that has become considerably popular, which increased interest in research about the aspects that can influence on the performance of these athletes, such as injuries, aerobic fitness and reaction time. Due to the ever-changing environment and high instability required for surfing, the surfers must develop some neuromuscular skills (agility, balance, muscle strength and flexibility) to acquire better performance in this modality. Nevertheless, there are still few scientific studies concerned about the investigation of these motor skills in surfing. Objective: The aim of this study was to evaluate the balance control in surfers compared to practitioners of other physical activities. Methods: Participants remained on a force platform while performing tasks involving visual deprivation (eyes open or closed) and somatosensory disturbance (steady surface or use of foam), with covariation of experimental conditions. The following variables were analyzed: speed and root mean square (RMS) displacement of the center of pressure in the anteroposterior (AP) and mediolateral (ML) directions. Results: The results showed no difference between groups during the experimental conditions, that is to say, both surfers and the control group varied over the conditions of eyes closed and on foam. Conclusion: Although surfing requires the surfer to have great balance control, the results did not reveal a relationship between this sport and better performance in balance control. However, we must consider the small sample size and the fact that this sport requires dynamic balance, while the study evaluated static balance.

Fat infiltration in the lumbar multifidus and erector spinae muscles in subjects with sway-back posture

Decreased activity of the lumbar stabilizer muscles has been identified in individuals with sway-back posture. Disuse can predispose these muscles to atrophy, which is characterized by a reduced cross-sectional area (CSA) and by fat infiltration. The aim of this study was to evaluate the amount of fat infiltration in the lumbar multifidus and lumbar erector spinae muscles as a sign of the muscle atrophy in individuals with sway-back posture, with and without low back pain. Forty-five sedentary individuals between 16 and 40 years old participated in this study. The sample was divided into three groups: symptomatic sway-back (SSBG) (n = 15), asymptomatic sway-back (ASBG) (n = 15), and control (CG) (n = 15). The individuals were first subjected to photographic analysis to classify their postures and were then referred for a magnetic resonance imaging (MRI) examination of the lumbar spine. The total (TCSA) and functional (FCSA) cross-sectional areas of the lumbar erector spinae together with lumbar multifidus and isolated lumbar multifidus muscles were measured from L1 to S1. The amount of fat infiltration was estimated as the difference between the TCSA and the FCSA. Greater fat deposition was observed in the lumbar erector spinae and lumbar multifidus muscles of the individuals in the sway-back posture groups than in the control group. Pain may have contributed to the difference in the amount of fat observed in the groups with the same postural deviation. Similarly, sway-back posture may have contributed to the tissue substitution relative to the control group independently of low back pain. The results of this study indicate that individuals with sway-back posture may be susceptible to morphological changes in their lumbar erector spinae and lumbar multifidus muscles, both due to the presence of pain and as a consequence of their habitual posture.

Influence of different types of seat cushions on the static sitting posture in individuals with spinal cord injury

Study design: Cross-sectional study. Objectives: To evaluate the efficacy of the Postural Assessment Software PAS/SAPO in the posture analysis of individuals with spinal cord injury (SCI) during sitting position and to analyze if the use of different types of seat cushions-gel and foam, with no cushion-can interfere in the individual's posture during sitting position. Setting: Centre of Rehabilitation at the University Hospital (FMRP-USP), Ribeirao Preto, Brazil. Methods: Eight individuals, four paraplegics and four tetraplegics with SCI and 20 healthy individuals participated in the study. Photos were taken of individuals in the sitting position using foam, gel cushions and with no cushion. They were analyzed using the PAS/SAPO. The alignment of the anterior-superior iliac spine (ASIS) and the posterior pelvic tilt were evaluated from the angle formed between the ASIS and the greater trochanter of the femur. Results: The group of healthy individuals presented the best postural alignment when compared with the group with SCI, both for the ASIS alignment (P < 0.05) and for the degree of posterior pelvic tilt (P < 0.05). No significant differences were found in the variables analyzed when the seat cushions were compared. Conclusion: The different types of cushions did not alter the sitting posture; however, individuals with SCI showed worse postural alignment than the healthy individuals. PAS/SAPO was demonstrated to be useful for postural assessment. Spinal Cord (2012) 50, 627-631; doi:10.1038/sc.2012.7; published online 21 February 2012

Fattori eziologici della Sindrome del Tunnel Carpale: una revisione sistematica con meta-analisi degli studi analitici

OBIETTIVO: sintetizzare le evidenze disponibili sulla relazione tra i fattori di rischio (personali e lavorativi) e l’insorgenza della Sindrome del Tunnel Carpale (STC). METODI: è stata condotta una revisione sistematica della letteratura su database elettronici considerando gli studi caso-controllo e di coorte. Abbiamo valutato la qualità del reporting degli studi con la checklist STROBE. Le stime studio-specifiche sono state espresse come OR (IC95%) e combinate con una meta-analisi condotta con un modello a effetti casuali. La presenza di eventuali bias di pubblicazione è stata valutata osservando l’asimmetria del funnel plot e con il test di Egger. RISULTATI: Sono stati selezionati 29 studi di cui 19 inseriti nella meta-analisi: 13 studi caso-controllo e 6 di coorte. La meta-analisi ha mostrato un aumento significativo di casi di STC tra i soggetti obesi sia negli studi caso-controllo [OR 2,4 (1,9-3,1); I(2)=70,7%] che in quelli di coorte [OR 2,0 (1,6-2,7); I(2)=0%]. L'eterogeneità totale era significativa (I(2)=59,6%). Risultati simili si sono ottenuti per i diabetici e soggetti affetti da malattie della tiroide. L’esposizione al fumo non era associata alla STC sia negli studi caso-controllo [OR 0,7 (0,4-1,1); I(2)=83,2%] che di coorte [OR 0,8 (0,6-1,2); I(2)=45,8%]. A causa delle molteplici modalità di valutazione non è stato possibile calcolare una stima combinata delle esposizioni professionali con tecniche meta-analitiche. Dalla revisione, è risultato che STC è associata con: esposizione a vibrazioni, movimenti ripetitivi e posture incongrue di mano-polso. CONCLUSIONI: I risultati della revisione sistematica confermano le evidenze dell'esistenza di un'associazione tra fattori di rischio personali e STC. Nonostante la diversa qualità dei dati sull'esposizione e le differenze degli effetti dei disegni di studio, i nostri risultati indicano elementi di prova sufficienti di un legame tra fattori di rischio professionali e STC. La misurazione dell'esposizione soprattutto per i fattori di rischio professionali, è un obiettivo necessario per studi futuri.

Hand and Wrist Surgery

Despite improved medical treatment of rheumatoid arthritis, carpal tunnel compression, caput ulnae syndrome and palmar and dorsal tenosynovitis with potential tendon rupture represent urgent surgical indications. While diagnostic and therapeutic synovectomy may guide medical treatment, it should be performed before joint instability and destructive arthritis are established. Swan-neck and Boutonniere deformities as well as ulnar or radial drift of metacarpophalangeal (MCP) joints or the wrist can only be corrected when the involved joints are supple and intact. In the presence of destructive arthritis, partial and total wrist fusion, arthroplasties of the MCP joints and arthrodeses of the distal interphalangeal joints are recommended.

MRI for differentiating ganglion and synovitis in the chronic painful wrist

OBJECTIVE: The purpose of our study was to determine if preoperative MRI can differentiate between occult ganglion and synovitis in the chronic painful wrist. CONCLUSION: MRI is accurate in preoperatively distinguishing between ganglion and synovitis in the setting of chronic dorsal wrist pain. Four main criteria were useful: margin, shape, internal structure, and enhancement after administration of contrast material, with shape and internal structure being most helpful.

Finite element study on fracture patterns in human scaphoid wrist bone due to free fall

Scaphoid is one of the 8 carpal bones found adjacent to the thumb supported proximally by Radius bone. During the free fall, on outstretched hand, the impact load gets transferred to the scaphoid at its free anterior end. Unique arrangement of other carpal bones in the palm is also one of the reasons for the load to get transferred to scaphoid. About half of the total load acting upon carpal bone gets transferred to scaphoid at its distal pole. There are about 10 to 12 clinically observed fracture pattern in the scaphoid due to free fall. The aim of the study is to determine the orientation of the load, magnitude of the load and the corresponding fracture pattern. This study includes both static and dynamic finite element models validated by experiments. The scaphoid model has been prepared from CT scans of a 27 year old person. The 2D slices of the CT scans have been converted to 3D model by using MIMICS software. There are four cases of loading studied which are considered to occur clinically more frequently. In case (i) the load is applied at the posterior end at distal pole whereas in case (ii), (iii) and (iv), the load is applied at anterior end at different directions. The model is given a fixed boundary condition at the region which is supported by Radius bone during the impact. Same loading and boundary conditions have been used in both static and dynamic explicit finite element analysis. The site of fracture initiation and path of fracture propagation have been identified by using max principal stress / gradient and max principal strain / gradient criterion respectively in static and dynamic explicit finite element analysis. Static and dynamic impact experiments were performed on the polyurethane foam specimens to validate the finite element results. Experimental results such as load at fracture, site of fracture initiation and path of fracture propagation have been compared with the results of finite element analysis. Four different types of fracture patterns observed in clinical studies have been identified in this study.

A practical posture for hand grip dynamometry in the clinical setting

The optimal testing position for hand grip strength, which is a useful functional measure of nutritional status, is open to debate. We therefore examined the systematic difference between different postures in order to establish a methodology that is clinically relevant, easy to perform and reproducible.