Estudo das variáveis cinemáticas da mastigação unilateral e habitual de indivíduos saudáveis / Study of the kinematic variables of unilateral and habitual mastication of healthy individuals

RESUMO Objetivo Descrever e comparar as variáveis cinemáticas temporoespaciais do movimento mandibular durante a mastigação unilateral deliberada e habitual de indivíduos saudáveis. Método Participaram do estudo 8 voluntários saudáveis, do gênero masculino, com faixa etária entre 19 e 24 anos. Os dados cinemáticos foram obtidos através do sistema de análise de movimento Qualysis (QTM - Qualisys Track Manager). Foram realizados registros de mastigação unilateral direita (MU) e habitual (MH) de bala de goma de gelatina de consistência firme. Foram analisadas variáveis relacionadas à (1) sequência mastigatória (duração, número de ciclos e frequência mastigatória); (2) ciclo mastigatório: duração do ciclo mastigatório, amplitude de movimento mandibular vertical e médio-lateral durante o ciclo mastigatório, velocidade máxima durante as fases de abertura e fechamento. A comparação das variáveis durante a MU e MH foi realizada por meio do teste t pareado (p<0,05) e os tamanhos de efeito (‘d’ de Cohen) foram calculados. Resultados Em relação à sequência mastigatória, observou-se menor frequência mastigatória durante MU comparada à MH (1,19±0,21 e 1,29±0,16Hz, respectivamente, p=0,004, d=0,53) e menores velocidades máximas de abertura (MU=67,4 mm/s e MH=80,02; p=0,053; d=0,80) e fechamento (MU=71,77±9,35mm/s e MH=83,51±17 mm/s, p=0,014, d=0,79) do ciclo mastigatório. Conclusão As variáveis cinemáticas relacionadas à sequência e ao ciclo mastigatório foram influenciadas pelo padrão mastigatório adotado – unilateral ou habitual.

ABSTRACT Purpose To describe and compare the temporal-spatial kinematic variables of mandibular movement during deliberate unilateral and habitual mastication in healthy young-adult individuals. Methods The study sample was composed of eight male healthy volunteers aged 19 to 24 years. The kinematic data were obtained using a motion analysis system - Qualisys Track Manager (QTM) ProReflex MCU. Recordings were performed during deliberate unilateral mastication (UM) and habitual mastication (HM) of firm-consistency gummy candy. The following variables were analyzed: (1) masticatory sequence: duration, number of masticatory cycles, and chewing rate; (2) masticatory cycle: duration, vertical and medial-lateral mandibular range of motion in relation to the skull, and maximum velocity during the opening and closing phases. Data of the variables were compared during UM and HM by the paired t test, and the effect sizes ('d' Cohen) were calculated. Results Regarding the variables of the masticatory sequence, smaller chewing rate was observed for UM compared with that for HM (1.19±0.21Hz and 1.29±0.16Hz, respectively, p=0.004, d=0.53). Smaller values of maximum velocity during the opening (MU=67.4 mm/s and MH=80.02, p=0.053, d=0.80) and closing (MU=71.77±9.35mm/s and MH=3.51±7mm/s, p=0.014, d=0.79) phases of the masticatory cycle were observed in deliberate unilateral mastication compared with those in habitual mastication. Conclusion Kinematic variables associated with the sequence and cycle of mastication are influenced by the chewing pattern adopted - deliberate unilateral or habitual.

Cervical-scapular muscles strength and severity of temporomandibular disorder in women with mechanical neck pain / Força dos músculos cérvico-escapulares e a severidade da disfunção temporomandibular em mulheres com cervicalgia mecânica

Abstract Introduction: Changes in cervical muscle function have been observed in patients with neck pain (NP) and TMD. However, the relationship between TMD severity and neck muscle strength in the presence/absence of NP is unknown. Objective: To determine the prevalence of TMD in women with and without mechanical NP and assess the cervical-scapular muscle strength and its association with TMD severity. Methods: Fifteen volunteers without neck pain (CG) and 14 women with mechanical neck pain (NPG) took part and were selected by the Neck Disability Index. The diagnosis and severity of TMD were determined by the Research Diagnostic Criteria for TMD and Temporomandibular Index (TI), respectively. The strength of the upper trapezius muscle, and cervical flexor and extensor muscles was measured by digital hand dynamometer. Results: 64.5% of women with NP and 33.3% without NP were diagnosed with TMD (p = 0.095). The NPG showed lower strength of the cervical flexor (p = 0.044) and extensor (p=0.006) muscles, and higher TI (p = 0.038) than in the CG. It was also verified moderate negative correlation between TI and the strength of dominant (p = 0.046, r = -0.547) and non-dominant (p = 0.007, r = -0.695) upper trapezius, and cervical flexors (p = 0.023, r = -0.606) in the NPG. Conclusion: There was no difference in the prevalence of TMD in women with and without NP. However, women with NP have lower cervical muscle strength - compared to those without NP - which was associated with greater severity of TMD. Thus, in women with NP associated with TMD, it is advisable to assess and address the severity of this dysfunction and identify the cervical-scapular muscles compromise.

Resumo Introdução: Modificações da função muscular cervical têm sido verificadas em pacientes com cervicalgia e DTM. Entretanto, ainda não é conhecida a relação entre a severidade da DTM e a força muscular cervical na presença/ausência de cervicalgia. Objetivo: Verificar a prevalência de DTM em mulheres com e sem cervicalgia mecânica, avaliar a força dos músculos cérvico-escapulares e sua associação com a severidade da DTM. Métodos: Participaram 15 voluntárias sem dor cervical (GC) e 14 mulheres com cervicalgia mecânica (GCM), selecionadas por meio do Índice de Disfunção Relacionada ao Pescoço. O diagnóstico e a gravidade da DTM foram determinados pelos Critérios diagnósticos para pesquisa em desordens temporomandibulares e Índice Temporomandibular (IT), respectivamente. A força dos músculos trapézio superior, flexores e extensores cervicais foi aferida por dinamometria digital manual. Resultados: 64,5% das mulheres com cervicalgia e 33,3% das sem dor cervical apresentaram diagnóstico de DTM (p = 0,095). O GCM apresentou menor força dos músculos flexores (p = 0,044) e extensores cervicais (p = 0,006) e maior IT (p = 0,038) que o GC. Também foi verificada correlação negativa moderada entre o IT e força dos músculos trapézio superior dominante (p = 0,046, r = -0,547), não dominante (p = 0,007, r = -0,695) e flexores cervicais (p = 0,023, r = -0,606) no GCM. Conclusão: Não houve diferença na prevalência de DTM entre mulheres com e sem cervicalgia. Entretanto, mulheres com cervicalgia apresentaram menor força muscular cervical (comparadas às sem cervicalgia) que esteve associada a maior severidade da DTM. Assim, em mulheres com cervicalgia associada à DTM, é recomendável avaliar e abordar a severidade desta disfunção e o comprometimento dos músculos cérvico-escapulares.

The addition of functional task-oriented mental practice to conventional physical therapy improves motor skills in daily functions after stroke

BACKGROUND: Mental practice (MP) is a cognitive strategy which may improve the acquisition of motor skills and functional performance of athletes and individuals with neurological injuries. OBJECTIVE: To determine whether an individualized, specific functional task-oriented MP, when added to conventional physical therapy (PT), promoted better learning of motor skills in daily functions in individuals with chronic stroke (13±6.5 months post-stroke). METHOD: Nine individuals with stable mild and moderate upper limb impairments participated, by employing an A1-B-A2 single-case design. Phases A1 and A2 included one month of conventional PT, and phase B the addition of MP training to PT. The motor activity log (MAL-Brazil) was used to assess the amount of use (AOU) and quality of movement (QOM) of the paretic upper limb; the revised motor imagery questionnaire (MIQ-RS) to assess the abilities in kinesthetic and visual motor imagery; the Minnesota manual dexterity test to assess manual dexterity; and gait speed to assess mobility. RESULTS: After phase A1, no significant changes were observed for any of the outcome measures. However, after phase B, significant improvements were observed for the MAL, AOU and QOM scores (p<0.0001), and MIQ-RS kinesthetic and visual scores (p=0.003; p=0.007, respectively). The significant gains in manual dexterity (p=0.002) and gait speed (p=0.019) were maintained after phase A2. CONCLUSIONS: Specific functional task-oriented MP, when added to conventional PT, led to improvements in motor imagery abilities combined with increases in the AOU and QOM in daily functions, manual dexterity, and gait speed. .