Electromyographic analysis of the up and down step: comparative dry and water

Electromyographic analysis of the up and down step: comparative dry and water The aim of the present study was to compare the muscular activity with surface electromyography of the lower limb and the trunk muscles during up and down step in dry land and into the water environments comparing young and elderly population. Methods: An analytical cross-sectional inferential study was carried out in order to compare the muscle activation between dry land and aquatic environments. Sixteen non-pathological subjects participated in the present study. Eight muscles were recorded in a telematic and simultaneous manner by immersing the device in water (if necessary) with a sampling frequency of 1000 Hz. The functional task up and down step was performed at a rhythm of 5 repetitions at 25 BPM (measured using a metronome), the height of the step was 18 cm. The task was performed both in dry and in water with the same height of the step and the same rhythm in both environments. The waterline was in one meter, water temperature was 30°C. Results: In older people, significant differences between dry and water during up step in the distribution of muscle activation were found. Young groups shown significant differences in all muscles analyzed with the exception of the spinal erector. However, for the down step in the group of young people (table 3), significant differences were observerd for all muscles except for the musculature of the trunk and rectus femoris In the aquatic environment, elderly group showed significant differences for the muscle activation compared to the young for all muscles of the thigh and leg except for the tibialis anterior during up step task. However, in the down step in the aquatic environment, only significant differences were obtained in favor of the elderly group in the musculature of the thigh.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

MTUG: an Instrumented Timed Up and Go Extended Test.

Background The aim of this study was to, using the inertial sensor found in the iPhone4®, locate in the ten meter Extended Timed Get Up and Go test the series of kinematic variables deriving from accelerometry and from angular velocity and displacement which show the greatest level of precision in order to discriminate between two groups of elderly persons (frail and physically active) compared to the traditionally used variable, namely time. Methods This study used the transversal analytical approach in an attempt to locate the series of kinematic variables which showed the highest degree of precision in order to discriminate between two groups. Firstly, the differences between the two groups (frail elderly persons and healthy elderly persons) were analyzed using variance analysis. The statistical significance level was established at p<0.05. Secondly, Receiver Operating Characteristic (ROC) curves were drawn up in order to evaluate the level of precision in the predictive capability of the kinematic variables compared to the traditionally used variable, namely time. Results In phases Si-St and T-St-Si, the results indicate that the variables for acceleration showed greater sensitivity in terms of discriminating between the population groups in the study than the angular velocity and displacement data; specifically, they were the minimum acceleration variables in motion axes x, z and y. In sub-phases GG and GC, accelerations in the x axis showed greater discrimination sensitivity between the frail and the controls. For the turning phase, the minimum acceleration variables which obtained area values below the curve greater than for time were the accelerations in the z and y axes. Conclusions The readings deriving from acceleration and angular velocity and displacement during the ETGUG test present a higher degree of precision in discrimination capability between a group of frail and a group of physically active elderly persons, in a more sensitive manner than the variable traditionally used in this test, namely time.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Validity and reliability of range of motion measured on smartphone (mROM)

Background: Nowadays, as internet-based communication is advancing rapidly, it is getting more and more interesting to adapt clinical examination of patients to remote communication. The use of smartphone photographic is presented as a method for studying the measurement of shoulders joint ROM. Objective: To investigate the reliability of smartphone photographic measurements of upper limbs abduction angle through mRom app compared to inertial sensors as the criterion standard. Methods: This cross-sectional involved 28 subjects: 14 healthy persons and 14 persons suffering from shoulder pathology. Descriptive and anthropometric independent variables were included. A physical property was included corresponding to a dependent variable: mobility angle (degrees), which was obtained thought two different devices. On the one hand, as criterion standard, the inertial measurement sensors with two inertial sensors (InertiaCube3™ Intersense Inc., Billerica, Massachusetts) located in the middle third of the humerus slightly posterior and in the flat part of the sternum. It contains an inertial 3 Degree of Freedom orientation tracking system: yaw, pitch, and roll. On the other hand, degrees were also obtained using a smartphone Nexus 4 (LG Electronics INC, Yeouido-dong, Seoul) with an 8 megapixels main camera and a 4.7 inches Corning Gorilla Glass 2 touchscreen. The app used was mROM Lite (Brain Dynamics SL, Málaga, Spain), available in google store. Three photographs were taken by two examiners from 3 independents set of images, and they were taken at the same time as inertial measurement. Participants were placed standing, starting from neutral position, performing shoulder abduction. Results: The mean ± SD age of the healthy participants (8 female, 6 male) was 56.1 ± 9.1 years, and their body mass index (BMI) was 27.12 ± 3.8 Kg/m2. The mean ± SD age of the participants with shoulder pathology (8 female, 6 male) was 54.4 ± 10 years and their average BMI was 28± 6.7 Kg/m2. Intraclass correlation coefficients ICC(2-1) for intrarrater reliability for inertial measurements taken by the first examiner was 0.993 (95%CI: 0.983, 0.998) for subject with pathological shoulders, 0.982 (95%CI: 0.736, 0.962) for healthy subjects and 0.992 (95%CI: 0.984, 0.996) for the total sample. Values for photographic measurements were 0.865 (95%CI: 0.670, 0.953) for healthy subjects, 0.991 (95%CI: 0.977, 0.997) for subjects suffering from shoulder pathology and 0.996 (95%CI: 0.992, 0.998) for the total sample. The ICC(2-1) for measurements taken by two different examiners was 0.711 (95%CI: 0.099, 0.907) for the first photograph, 0.703 (95% CI: 0.076, 0.905) for the second one and 0.892 (95%CI: 0.663, 0.965) for the third one in healthy subject. In subject with pathology it was 0.994 (95% CI: 0.982, 0.998), 0.998 (95% CI: 0.993, 0.999) and 0.996 (95% CI: 0.989, 0.999) respectively. In the total sample it was 0.997 (95%CI: 0.992, 0.998), 0.998 (95%CI: 0.995, 0.999) and 0.998 (95%CI: 0.995, 0.999) respectively. Conclusions: Smartphone photographic measurements of upper limbs abduction angle through mRom app are reliable compared to inertial sensors. This method provides a convenient and precise tool in assessment of shoulder motion.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

EMG Analysis of the Neuromuscular Activity during Sit-to-Stand from Different Height Chairs in Water

The purpose of this study was to use surface electromyography to measure the muscular activity during the sit-to-stand task in water and compare it at three different chair heights. Ten healthy young adults [5 males and 5 females (mean ± SD): age, 22.0 ± 3.1 yr; height, 172.8 ± 9.0 cm; body mass, 63.9 ± 17.2 kg] were recruited for study. We used a telemetry EMG system on the following muscles on the right side of the body: quadriceps (vastus medialis and rectus femoris), long head of the biceps femoris, tibialis anterior, gastrocnemius medialis, soleus, rectus abdominis, and erector spinae). Each participant performed the sit-to-stand test five times at each of three different chair heights underwater. No significant differences in muscular activity of all muscles measured during the performance of the sit-to-stand exercise in water were found for any of the chair heights. This study for the first time described the neuromuscular responses in healthy subjects during the performance of the sit-to-stand task in water at different chair heights. The muscular activity of lower limb and trunk should be considered when using the sit-to-stand movement in aquatic rehabilitation

Validity of the new backache index (BAI) in patients with low back pain

INTRODUCTION: The Backache-Index (BAI) is applied to patients with low back pain (LBP) in order to help doctors/surgeons perform physical examinations easily and it is carried out within a short space of time (< 2 min.) without using inclinometric instruments. PURPOSE/AIM: To explore reliability, validity and responsiveness of the BAI in patients with LBP, which can fulfil the existing need for a reliable routine examination in the clinical environment. MATERIALS & METHODS: In total, 75 patients with subacute LBP participated in a randomized controlled study (1). The BAI consisted of a scoring system that includes pain factors and stiffness estimation at the end of a series of five different lumbar movements of a patient standing in erect position. RESULTS: The (blinded) inter-observer reliability between 2 observers for the BAI was perfect (ICC = 0.96). A BAI change of one unit is able to exclude a measurement error. A significantly good correlation (P < 0.001) was found between BAI at baseline, and Oswestry Disability Index (ODI, R = 0.62) and MPQ-PRIT, as the total degree of pain rating index (R = 0.57). The effect size and discriminative ability were explored after two treatment sessions. The greatest level of distinction was found for MPQ-PRI-T and BAI (AUC > 0.93), followed by ODI (AUC = 0.92). A less distinction was found for MPQ-NWC-T and Visual Analogue Scale (VAS, AUC > 0.82). RELEVANCE: the BAI is available in different languages: English, Spanish, French, Dutch, German, ITALIAN, Portuguese, Russian, Turkish, Hebrew, Chinese, Japanese and Thais. www.roptrotherapy.info CONCLUSIONS: The Backache Index or BAI appears to be a reliable and valid assessment of overall restricted spinal movements in case of LBP and discriminates between successful and unsuccessful treatment outcome. DISCUSSION: The inter-observer reliability after a few minutes for the BAI was sufficient. The validity of the BAI was found to be good with the ODI and moderate with the VAS. A Backache Index change of one unit is able to exclude a measurement error. KEYWORDS: Low back pain; Outcome scales; Reliability; Validity; Impairment; Pain rating scales. IMPLICATIONS: In a Spanish study (2) the test-retest after 3 days of the same group (n=46) revailed that the reliability for the 5 outcome scores was good (ICC=0.73). No significant difference was found between BAI1 (4.65 ± 4.15 ) and BAI2 (4.72 ± 4.20) and the absolute reliability was perfect with an ICC=0.97.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Differences in the biomechanical response between healthy and low back pain patients from a isometric extension test

Purpose: To compare, in healhty subjects and low back pain patients, the erector spinal muscle response in a máximum isometric contraction intensities using simultaneously electromyography and ultrasonography. Participants: 59 subjects: 33 Healthy persons (45% ♀). 26 LBP patients (39% ♀) with a mean age of 30.39 (±7.785). Methods: Cross sectional study. Participants, following a maximal strength test as measured by a load cell, perform an isometric contraction of maximum strength. From sitting, each subject develops a maximum isometric lumbar extension, locked at 45 degrees from vertical. The hip and this of the subject were attached by a strap. After preliminary training, each subject performed three repetitions of described gesture resting for a minute and a half between each attempt. Records were taken throughout the maximum contraction, EMG signal and a ultrasonography image, for each ES (right and left). Measured torque, inclination angle, thickness and electromyography activation (MVC). Analysis: We performed a descriptive analysis of both groups and subsequently made T-Student test for independent data in each of the variables measured. Results: Mean values for groups of healthy subjects and low back pain patients were, respectively: Torque: 61.652 (±20.137); 70.298 (±25.053). Right Angle: 6.48 (±2.181); 7.15 (±2.53). Left Angle: 5.36 (±2.26); 6.38 (±1.86). Right Thickness: 0.031 (±0.005); 0.033 (±0.008). Left Thickness: 0.032 (±0.006); 0.034 (±0.006). Right MVC: 558.64 (±211.029); 576.15 (±267.69). Left MVC: 589.21 (±257.739); 671.15 (±370.722). No significant differences were found in any variable when comparing the results between healthy subjects and low back pain patients. Torque: −8.65 (±9.02) (p = 0.347). Angle: Right: −0.659 (±0.613) (p = 0.280); Left: −1.021 (±0.549) (p = 0.068). Thick-ness: Right: 0.00 (±0.00) (p=0.259); Left: 0.00 (±0.00) (p=0.069). MVC: Right: -17.52 (±62.29) (p=0.780). Left: −81.84 (±81.91) (p = 0.321). Conclusions: Knowing how the erector spinal muscle behaves in a isometric back extension test, noting that biomechanically there are not significant differences in the responses with respect to a healthy subject, physical therapists could perform planning treatment which is the biopsychosocial model supported by the biomechanical model.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

A comparison land-water environment of maximal voluntary isometric contraction during manual muscle testing through surface electromyography

Background The aim of this study was to compare through surface electromyographic (sEMG) recordings of the maximum voluntary contraction (MVC) on dry land and in water by manual muscle test (MMT). Method Sixteen healthy right-handed subjects (8 males and 8 females) participated in measurement of muscle activation of the right shoulder. The selected muscles were the cervical erector spinae, trapezius, pectoralis, anterior deltoid, middle deltoid, infraspinatus and latissimus dorsi. The MVC test conditions were random with respect to the order on the land/in water. Results For each muscle, the MVC test was performed and measured through sEMG to determine differences in muscle activation in both conditions. For all muscles except the latissimus dorsi, no significant differences were observed between land and water MVC scores (p = 0.063–0.679) and precision (%Diff = 7–10%) were observed between MVC conditions in the muscles trapezius, anterior deltoid and middle deltoid. Conclusions If the procedure for data collection is optimal, under MMT conditions it appears that comparable MVC sEMG values were achieved on land and in water and the integrity of the EMG recordings were maintained during wáter immersion

Studying upper-limb kinematics using inertial sensors

AIM: The aim of this study was to analyze scapulohumeral rhythm through nine physical properties that correspond to angular mobility, angular velocity, and acceleration in the three axes of space, obtained by inertial sensors. METHODS: This cross-sectional study recruited healthy young adult subjects. Descriptive and anthropometric independent variables related to age, gender, weight, size, and BMI were included. Nine physical properties were included corresponding to three dependent variables for each of three special axes: mobility angle (degrees), angular speed (degrees/second), and lineal acceleration (meters/seconds2), which were obtained thought the inertial measurement sensors with four inertial sensors (InertiaCube3™ Intersense Inc., Billerica, Massachusetts). Inertial sensors were placed in the right half of the body of each subject located in the middle third of the humerus slightly posterior, in the middle third of the upper spine of the scapula, in the flat part of the sternum, and the distal surface of the ulna and radius. RESULTS: Descriptive graphics of analytical tasks performed were obtained (figure 1). The main difference in mobility between the scapula and humerus was found in pitch axis for abduction ( = 107.6°, SD = 9.3°) and flexion ( = 113.1°, SD = 9.3°). CONCLUSION: This study shows how much each body segment contributes to upper-limb motion, and allows us to obtain grades of mobility provided by the scapula. Also, this study identified movement patterns, and supports inertial sensors as a useful device to analyze upper-limb kinematics. However, further studies with subjects with shoulder pathology should be carried out.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Functional and structural of the erector spinae muscle during iso-metric lumbar extension

Study Design: cross-sectional study. Objectives: to compare erector spinae (ES) muscle fatigue between chronic non-specific lower back pain (CNLBP) sufferers and healthy subjects from a biomechanical perspective during fatiguing isometric lumbar extensions. Background: paraspinal muscle maximal contraction and fatigue are used as a functional predictor for disabilities. The simplest method to determine muscle fatigue is by evaluating the evolution during specific contractions, such as isometric contractions. There are no studies that evaluate the evolution of the ES muscle during fatiguing isometric lumbar extensions and analyse functional and architectural variables. Methods: In a pre-calibrated system, participants performed a maximal isometric extension of the lumbar spine for 5 and 30 seconds. Functional variables (torque and muscle activation) and architecture (pennation angle and muscle thickness) were measured using a load cell, surface electromyography and ultrasound, respectively. The results were normalised and a reliability study of the ultrasound measurement was made. Results: The ultrasound measurements were highly reliable, with Cronbach's alpha values ranging from 0.951 0.981. All measured variables shown significant differences before and after fatiguing isometric lumbar extension. Conclusion: During a lumbar isometric extension test, architecture and functional variables of the ES muscle could be analised using ultrasound, surface EMG and load cell. In adition, during an endurance test, ES muscle suffers an acute effect on architectural and functional variables.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. 25 September 2013 through 28 September 2013; Code 10172