Luciana C. C. B. Silva

Reliability of intra- and inter-rater palpation discrepancy and estimation of its effects on joint angle measurements

This study presents data on the intra- and inter-rater reliability of palpation on normal and overweight subjects and shows the influence of palpation discrepancy on angular variability for a collected data set, using computer simulation. Thirty healthy males were recruited. Two physiotherapists identified 12 anatomical landmarks that enabled measurement of eight joint angles. Palpation discrepancy was determined by photographic recordings under ultraviolet light. Angular discrepancies were determined from photos of the subjects orthostatic posture. A computer simulation was developed to predict expected angular variation according to observed palpation discrepancy. The results showed that the inter-rater reliability was lower than the intra-rater reliability for both palpation and angle measurements. Palpation of the greater trochanter (GT), anterior superior iliac spine (ASIS), seventh cervical vertebra (C7) and femoral epicondyle (FE) showed larger discrepancies. The overweight group presented a significant difference in palpation discrepancy for ASIS (P<0.03). Angular variations were associated with palpation discrepancies for trunk flexion (TF), hip flexion (HF) and pelvic inclination (PI). Therefore, measurements should be performed by a single rater, rather than by different raters, if reliable angular measurements are intended. Specific anatomical landmarks require careful identification. Simulation was useful for providing estimates of variations due to palpation discrepancy.

Prevalence of musculoskeletal symptoms in hospital nurse technicians and licensed practical nurses: associations with demographic factors

Objective : This cross-sectional study aimed at analyzing: 1. the main musculoskeletal symptoms (MSS) presented by hospital nursing workers and; 2. personal, occupational, and health factors related to MSS among them. Method : Two questionnaires were filled in by 245 nurse technicians (NTs) and licensed practical nurses (LPNs) (response rate 95%) associated with direct patient care sectors from a hospital. These questionnaires were: the standardized version of the Nordic Musculoskeletal Questionnaire (NMQ) and one including questions on 15 demographic independent variables potentially related to outcomes from the NMQ. Univariate analyses and binary logistic regression analyses were performed to identify which variables would explain the occurrence of MSS in different body regions. Results: The low back (57%), shoulder (52%), and neck (48%) were identified as the most affected regions. The logistic regression analysis showed that low back symptoms in the last 12 months were significantly associated with LPN activities (OR=2.36; CI=1.24-4.5) and previous sick leave due to MSS (OR=5.97; CI=1.2-29.1). Smoking was significantly associated with symptoms in the low back (OR=2.77; CI=1.13-6.8) and thoracic spine (OR=2.37; CI=1.04-5.40). Physical exercise showed a protective effect on the cervical spine (OR=0.42; CI=0.23-0.77). Previous sick leave was significantly associated with pain in the knees (OR=4.24; CI=1.33-13.5) and in the upper limbs (OR=5.36; CI=1.07-26.7). Conclusions: The nursing workers who were evaluated presented a high prevalence of MSS. Previous history of sick leave was strongly associated with the presence of symptoms in various body regions. These results indicate the need for preventive programs in the hospital environment in order to control more severe MSS in nursing professionals.

How do low/high height and weight variation affect upper limb movements during manual material handling of industrial boxes?

OBJECTIVES To evaluate the effect of surface height and load weight on upper limb movements and electromyographic (EMG) recordings during manual handling performed by both experienced and inexperienced lifter subjects. METHODS Sixteen experienced and sixteen inexperienced lifters handled a box (both 7 and 15 kg) from an intermediate height (waist level) to either a high or low surface. Electromyography and video images were recorded during the tasks. The 10th, 50th and 90th percentiles were calculated for the deltoid and biceps muscles, shoulder flexion, shoulder abduction, and elbow flexion movements. Groups, right/left sides, weights and heights were compared. There were no differences between either groups or sides. RESULTS Weight and height variations affected EMG and posture, although weight had more impact on EMG. Shoulder abduction and flexion movements higher than 60º occurred, particularly for the higher surface. Shoulder flexion was also higher when the box was moved to the low height. This study provides new evidence as shoulder postures during boxes handling on low surfaces had not previously been evaluated. CONCLUSIONS The high demand of upper limb in manual material handling tasks is clear, particularly for the shoulder. This knowledge can be used by physical therapists to plan better rehabilitation programs for manual material handling-related disorders, particularly focusing on return to work.

Wrist electrogoniometry: are current mathematical correction procedures effective in reducing crosstalk in functional assessment?

BACKGROUND The recording of human movement is an essential requirement for biomechanical, clinical, and occupational analysis, allowing assessment of postural variation, occupational risks, and preventive programs in physical therapy and rehabilitation. The flexible electrogoniometer (EGM), considered a reliable and accurate device, is used for dynamic recordings of different joints. Despite these advantages, the EGM is susceptible to measurement errors, known as crosstalk. There are two known types of crosstalk: crosstalk due to sensor rotation and inherent crosstalk. Correction procedures have been proposed to correct these errors; however no study has used both procedures in clinical measures for wrist movements with the aim to optimize the correction. OBJECTIVE To evaluate the effects of mathematical correction procedures on: 1) crosstalk due to forearm rotation, 2) inherent sensor crosstalk; and 3) the combination of these two procedures. METHOD 43 healthy subjects had their maximum range of motion of wrist flexion/extension and ulnar/radials deviation recorded by EGM. The results were analyzed descriptively, and procedures were compared by differences. RESULTS There was no significant difference in measurements before and after the application of correction procedures (P<0.05). Furthermore, the differences between the correction procedures were less than 5° in most cases, having little impact on the measurements. CONCLUSIONS Considering the time-consuming data analysis, the specific technical knowledge involved, and the inefficient results, the correction procedures are not recommended for wrist recordings by EGM.

Can experience modulate handler responses to boxes designed to decrease musculoskeletal load

Abstract Biomechanical load during the handling of commercial (cardboard box with and without cut out) and non-commercial boxes (cardboard box with a retreat on the bottom edges), on experienced compared to inexperienced subjects was evaluated. Thirty-seven inexperienced and 21 experienced workers handled all boxes at shoulder and ground levels. Biomechanical load on upper limb was investigated through posture and electromyography (EMG) recordings. Comfort and effort were assessed immediately after each handling. In general, experienced workers had low range of motion. On the other hand, EMG was similar between both groups, except when non-commercial boxes were handled in non-favourable heights. Comfort was higher when a non-commercial box was handled versus a commercial one, regardless of the group. Both groups had a lower biomechanical load when handling the non-commercial boxes compared to the commercial ones. However, experienced workers did not have the same advantage as inexperienced subjects when handling those new boxes. Practitioner Summary: Box designs favouring intuitive hand coupling and more efficient postures have potential to reduce the risk of upper-limb musculoskeletal disorders in inexperienced subjects. However, ergonomist has to deal with workers on different levels of experience. Results of this study can support the development of effective recommendations for the working context.

Are cutout handles used when available in real occupational settings? Description of grips and upper extremities movements during industrial box handling.

In order to achieve better postures and decrease musculoskeletal risks adequate design of hand/box couplings for manual materials handling (MMH) are still needed. No studies evaluating upper limb movement thorough direct measurements during box handling in workplace were identified in the literature. In this study we describe the types of grip and movements adopted by ten workers when handling redesigned boxes with cutout handles between different heights on industrial pallets. The new handles were used by 90% of the workers through different types of grip. Electrogoniometric measurements showed relatively safe forearm and wrist movements, although elbow inadequate range of movement was recorded. Despite the good acceptance of the cutout by workers, the new design requires extra internal space in the boxes reducing applications for this alternative of box.

How is a box handled when all surfaces can be freely held

In this study, we investigated how experienced and inexperienced subjects handle a box when it could be approached from any of its sides. Subjects moved a box (11 kg) either to a high (HS) or a low surface (LS). Wrist movements and grip force were synchronised and recorded, respectively, by electrogoniometers and an instrumented box. All subjects adopted a lateral-and-bottom grip, with parts of the hands simultaneously placed on the side and bottom of the box. This grip allowed the 50th percentile of wrist movements to be within safe limits, particularly in the sagittal plane. Low force was associated with lowering the box to LS and equally distributed but greater force when lifting to HS. Larger ulnar deviation was recorded when the box was lifted to HS. Only peak of wrist extension differentiated experienced from inexperienced subjects, with experienced presenting larger wrist extension. Alternative box designs are suggested to improve handling in real settings. Practitioner Summary Understanding worker preferences for box lifting behaviour can contribute to the development of new designs that facilitate the adoption of more efficient postures while reducing the risk of upper-limb musculoskeletal disorders and promoting safer manual material handling.

30º inclination in handles of plastic boxes can reduce postural and muscular workload during handling

BACKGROUND The handling of materials, which occurs in the industrial sector, is associated with lesions on the lumbar spine and in the upper limbs. Inserting handles in industrial boxes is a way to reduce work-related risks. Although the position and angle of the handles are significant factors in comfort and safety during handling, these factors have rarely been studied objectively. OBJECTIVE To compare the handling of a commercial box and prototypes with handles and to evaluate the effects on upper limb posture, muscle electrical activity, and perceived acceptability using different grips while handling materials from different heights. METHOD Thirty-seven healthy volunteers evaluated the handles of prototypes that allowed for changes in position (top and bottom) and angle (0°, 15°, and 30°). Wrist, elbow, and shoulder movements were evaluated using electrogoniometry and inclinometry. The muscle electrical activity in the wrist extensors, biceps brachii, and the upper portion of the trapezius was measured using a portable electromyographer. The recorded data on muscle movements and electrical activity were synchronized. Subjective evaluations of acceptability were evaluated using a visual analog scale. RESULTS AND CONCLUSIONS The prototypes with handles at a 30° angle produced the highest acceptability ratings, more neutral wrist positions, lower levels of electromyographic activity for the upper trapezius, and lower elevation angles for the arms. The different measurement methods were complementary in evaluating the upper limbs during handling.

Qual modelo de eletrogoniômetro é mais adequado para avaliar movimentos do punho

INTRODUCAO: O eletrogoniometro e utilizado em contexto ocupacional para registro dos movimentos do punho. No entanto, diferentes tamanhos de sensores sao utilizados, o que pode dificultar a comparacao entre os resultados. OBJETIVO: Avaliar dois sensores de tamanho diferentes para verificar o desempenho de ambos em uma amostra com variaveis antropometricas definidas. MATERIAIS E METODOS: Participaram 13 sujeitos (7 mulheres e 6 homens; idade 23 ± 2,6 anos; massa 57 ± 3,8 kg e altura 1,63 ± 4,1 m). Foram utilizados dois sensores com 65 e 110 mm de comprimento (XM65 e XM110, respectivamente) e um dispositivo de aquisicao de dados (Datalog, Biometrics). Medidas antropometricas dos participantes foram registradas. Cada individuo realizou movimentos de flexao/extensao e desvios ulnar/radial, atingindo amplitude maxima, na posicao pronada do antebraco. A ordem de realizacao dos movimentos e colocacao dos sensores foi aleatorizada. Os dados foram analisados descritivamente e estatisticamente (analise multivariada). Foi calculada a variacao entre as tentativas (variabilidade intraindividual) e entre os sensores por meio do valor RMS (root mean square). RESULTADOS: Nao houve diferenca significativa entre os sensores para todos os movimentos. A variabilidade intraindividual maxima foi de 2,2o. Houve diferenca significativa entre os generos para a flexao e o desvio ulnar, sendo as mulheres as que apresentam valores maiores que os homens. A variabilidade maxima entre os sensores foi de 7,1o. CONCLUSAO: Apesar de nao identificar diferenca significante entre os sensores, verificou-se que o sensor XM110 sofria abaulamento durante a extensao. Portanto, para individuos com altura ate 1,8 m, os dados obtidos pelos diferentes sensores sao comparaveis.