Interaction of scapular dyskinesis with hand dominance on three-dimensional scapular kinematics.

INTRODUCTION: This study aimed to evaluate the effect of scapular dyskinesis and its interaction with hand dominance and humerothoracic angles on three-dimensional scapular kinematics in asymptomatic individuals in all planes of arm motion. METHODS: Forty-five asymptomatic participants, seventeen men and twenty-eight women, were separated into two groups: with (n = 22) and without scapular dyskinesis (n = 23) according to the Yes/No classification. Scapular kinematic data of dominant and non-dominant sides in both groups were measured with an electromagnetic tracking device during arm elevation and lowering phases in scapular, frontal and sagittal planes. A linear mixed model of covariance adjusted for age and BMI was used, which included hand dominance (dominant and non-dominant), group (with and without scapular dyskinesis), angles (30°, 60°, 90°, and 120°), and the interaction effect (group × hand dominance × humerothoracic angle). RESULTS: There was a significant interaction effect on scapular anterior tilt and upward rotation in the sagittal plane, and for internal rotation and anterior tilt in the frontal and scapular planes. The effects of hand dominance on three-dimensional scapular kinematics, as increased anterior tilt, internal rotation and upward rotation, were greater in individuals without scapular dyskinesis. CONCLUSION: The effects of dominant side as increased upward rotation, internal rotation, and anterior tilt at higher humerothoracic angles for all planes of arm motion, were greater in individuals without scapular dyskinesis. Our findings may assist the scapular assessment which in individuals without scapular dyskinesis, bilaterally, possible between side differences in the scapular motions may be related to a dominance effect.

Choosing what works for whom: towards a better use of mechanistic knowledge in clinical practice.

BACKGROUND: Clinicians commonly try to use mechanism-based knowledge to make sense of the complexity and uncertainty of chronic pain treatments to create a rationale for their clinical decision-making. Although this seems intuitive, there are some problems with this approach. DISCUSSION: The widespread use of mechanism-based knowledge in clinical practice can be a source of confusion for clinicians, especially when complex interventions with different proposed mechanisms of action are equally effective. Although the available mechanistic evidence is still of very poor quality, in choosing from various treatment options for people with chronic pain, an approach that correctly incorporates mechanistic reasoning might aid clinical thinking and practice. CONCLUSION: By explaining that not all evidence of mechanism is the same and by making a proposal to start using mechanism-based knowledge in clinical practice properly, we hope to help clinicians to incorporate mechanistic reasoning to prioritize and start choosing what may best work for whom.

Inclinometer Reliability for Shoulder Ranges of Motion in Individuals With Subacromial Impingement Syndrome.

OBJECTIVE: This study aimed to determine the intra- and interrater reliability of active and passive range of motion in the shoulders of individuals with subacromial impingement syndrome using a digital inclinometer. METHODS: The raters evaluated active and passive range of motion in the shoulder of 50 individuals with unilateral subacromial impingement syndrome in movements including flexion, abduction, extension, external rotation in a neutral position, external rotation with the arm at 90° of abduction, and internal rotation with the arm at 90° of abduction. The tests were performed by 2 examiners on the same day, with a 10-minute interval, and were repeated by 1 examiner after a 2- to 4-day interval. Reliability was analyzed using the intraclass correlation coefficient (ICC2,3). RESULTS: There was moderate to excellent interrater (ICC2,3 = 0.50-0.95) and intrarater (ICC2,3 = 0.74-0.94) reliability. In the interrater analysis, the standard error of measurement (SEM) ranged from 4.1° to 10°, the percentage SEM (%SEM) ranged from 2% to 17%, and the minimum detectable change ranged from 9.5° to 23.4°. In the intrarater analysis, the SEM ranged from 4° to 9.2°, %SEM ranged from 3% to 14%, and the minimum detectable change ranged from 9.3° to 21.4°. CONCLUSION: The digital inclinometer showed moderate to excellent reliability for measuring active and passive range of motion in shoulders with unilateral subacromial impingement syndrome.

Altered Scapular Time Series in Individuals With Subacromial Pain Syndrome.

Altered scapular movement in subacromial pain syndrome has been demonstrated using discrete data reduction approach. However, this approach does not consider the data collinearity and variability, and scapular translations are poorly investigated in symptomatic individuals. The purpose of this study was to investigate the scapular rotation and translation of asymptomatic individuals and those with subacromial pain syndrome during arm motions using principal component analysis. Scapulothoracic kinematics were evaluated in 47 participants with subacromial pain syndrome and 50 asymptomatic individuals. The symptomatic group had increased range of scapular anterior/posterior tilt during arm elevation (P = .01, effect size = .59) and arm lowering (P < .01, effect size = .61), and increased range of scapular forward/backward translation during arm lowering (P < .01, effect size = .60) compared with the asymptomatic group. In addition, the symptomatic group had a reduced difference in anterior tilt angular velocities between the early-arm and mid-arm lowering phases and between the mid- and late-arm lowering phases compared with the asymptomatic group (P = .03, effect size = .44). This study demonstrated that scapular anterior/posterior tilt motion and angular velocity and scapular forward/backward translation of symptomatic individuals were different from asymptomatic individuals when considering the entire arm movement.

From Paper to Digitalized Body Map: A Reliability Study of the Pain Area.

BACKGROUND: Computerized methods to analyze pain drawings (PDs) have been developed and may aid to measure the pain area more precisely. OBJECTIVE: The aim of this study was to verify whether examiners can reproduce the patient's PDs with acceptable reliability. METHODS: This was an intra-rater and inter-rater reliability study. The protocol consisted of 4 steps: (1) scanning of paper PDs; (2) sharing the digitalized PD images between examiners; (3) reproducing the PD images in the sketching application; and (4) calculating the pain area in pixels and percentages. We calculated intraclass correlation coefficients (ICCs; 2,1), the standard error of the measurement (SEM), and the smallest detectable difference (SDD). RESULTS: Reliability was tested using 31 PDs from 17 patients in our database (11 female [64.7%], mean age: 53.23 ± 11.57 years). Intra-rater reliability varied from ICC (2,1) = 0.991 (95% confidence interval [CI] = 0.982 to 0.996; SEM = 3,432.45; SDD = 162.39 pixels; P < 0.001) to ICC (2,1) = 0.992 (95% CI = 0.978 to 0.997; SEM = 3,412.96; SDD = 161.93 pixels; P < 0.001). Inter-rater reliability for the measurement between all examiners was considered excellent (ICC [2,1] = 0.976; 95% CI = 0.956 to 0.987; SEM =8,580.75; SDD = 256.76 pixels; P < 0.001), being higher between Examiners A and C (ICC [2,1] = 0.970; 95% CI = 0.936 to 0.986; SEM = 6,453.34; SDD = 222.67 pixels; P < 0.001). CONCLUSION: Our results show that intra- and inter-rater reliabilities were excellent when an examiner reproduced the paper PDs into digitalized PDs. This process gives clinicians and researchers the opportunity to analyze pain extent more precisely using a computerized method.

Fatigue analysis in the masseters and temporalis muscles in patients with temporomandibular disorder during short period of mastication.

The purpose of this experiment was to look for signals of muscle fatigue in volunteers with Temporomandibular Disorders (TMD) during short period of mastication. Twenty female volunteers selected by Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) participated, 10 with myogenic TMD (experimental) and 10 clinically normal (control). The Masseter and Temporalis muscles were evaluated electromyographically with active differential surface electrodes. The masticatory activity was recorded for 15 seconds and the signals were normalized by 4 seconds of teeth clenching. Three complete masticatory cycles were taken to calculating the median frequency (MF) and electromyographic amplitude (RMS). The data were submitted to statistics analysis and non-parametric tests. The results showed that RMS and median frequency did not change during the mastication period analyzed, indicating the absence of muscle fatigue, for the Masseter and Temporalis muscles in both groups (p> 0.05). These results confirm the absence of signals of muscle fatigue in masticatory muscles during short period of mastication even in individuals with TMD, possibly due to increased of blood flow, consequence of dynamic muscle contraction and the individual characteristics of muscle fiber composition and recruitment.

Fatigue analysis in the masseters and temporalis muscles in patients with temporomandibular disorder during short period of mastication

The purpose of this experiment was to look for signals of muscle fatigue in volunteers with Temporomandibular Disorders (TMD) during short period of mastication. Twenty female volunteers selected by Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) participated, 10 with myogenic TMD (experimental) and 10 clinically normal (control). The Masseter and Temporalis muscles were evaluated electromyographically with active differential surface electrodes. The masticatory activity was recorded for 15 seconds and the signals were normalized by 4 seconds of teeth clenching. Three complete masticatory cycles were taken to calculating the median frequency (MF) and electromyographic amplitude (RMS). The data were submitted to statistics analysis and non-parametric tests. The results showed that RMS and median frequency did not change during the mastication period analyzed, indicating the absence of muscle fatigue, for the Masseter and Temporalis muscles in both groups (p>0.05). These results confirm the absence of signals of muscle fatigue in masticatory muscles during short period of mastication even in individuals with TMD, possibly due to increased of blood flow, consequence of dynamic muscle contraction and the individual characteristics of muscle fiber composition and recruitment.

A proposta deste experimento foi procurar sinais de fadiga muscular em voluntarios com disfuncao temporomandibular (DTM) durante curto periodo de mastigacao. Vinte voluntarios do sexo feminino foram selecionados pelo Criterio de Diagnostico de Pesquisa para desordem tempomandibular, 10 com DTM miogenica (experimental) e 10 clinicamente normais (controle). Os musculos Masseter e Temporal foram avaliados eletromiograficamente com eletrodos diferenciais de superficie ativos. A atividade mastigatoria foi registrada por 15 segundos e os sinais foram normalizados por 4 segundos de apertamento dental. A frequencia mediana (FM) e da amplitude eletrmoigrafica (RMS) dos sinais eletromiograficos foram obtidos em 3 diferentes intervalos de tempo. Os valores da FM e RMS foram submetidos a analise estatistica descritiva e a testes nao parametricos. Os resultados demonstraram que o RMS e a FM nao mudaram durante o periodo de mastigacao, indicando ausencia de fatiga muscular para o musculo Masseter e Temporal, em ambos os grupos (p>0.05). Estes resultados confirmam a ausencia de sinais de fatiga muscular durante curto periodo de mastigacao, mesmo em individuos com DTM, possivelmente devido ao aumento do fluxo sanguineo em consequencia da dinamica de contracao muscular e das caracteristicas individuais da composicao das fibras musculares e do recrutamento.

Anamnestic index severity and signs and symptoms of TMD.

The aim of this study was to determine the frequency and to characterize the symptoms and clinical signs of temporomandibular disorders (TMD) related to each severity category of Fonseca's anamnestic index in a sample of Brazilian young adults (mean age 21.61+/-1.91 years, 87% females and 13% males), by the application of an anamnestic index proposed by Fonseca (1992) and by clinical examination considering mandibular range of motion and tenderness to palpation of stomatognathic system structures. A significant number of participants were classified with mild TMD (43.2%) and moderate TMD (34.8%). Pain frequency during mastication, temporomandibular joint (TMJ) pain, and TMJ sounds were shown to be good predictors of TMD severity. Neck pain, headache, difficulty during mouth opening and lateral deviation, and tenderness to palpation of masticatory sites and during protrusion accompanied the TMD severity but failed to demonstrate differences between moderate and severe groups, showing a poor ability to determine TMD severity progression. This study suggests that not only the frequency of signs and symptoms of TMD should be determined, but also symptom severity and its relationship to the presence of clinical signs in order to discriminate patients with real treatment needs in nonpatient samples.