Can masticatory electromyography be normalised to submaximal bite force?

The combination of bite force and jaw muscle electromyography (EMG) provides an insight into the performance of the stomatognathic system, especially in relation to dynamic movement tasks. Literature has extensively investigated possible methods for normalising EMG data encapsulating many different approaches. However, bite force literature trends towards normalising EMG to a maximal voluntary contraction (MVC), which could be difficult for ageing populations or those with poor dental health or limiting conditions such as temporomandibular disorder. The objectives of this study were to (i) determine whether jaw-closing muscle activity is linearly correlated with incremental submaximal and maximal bite force levels and (ii) assess whether normalising maximal and submaximal muscle activity to that produced when performing a low submaximal bite force (20 N) improves repeatability of EMG values. Thirty healthy adults (15 men, 15 women; mean age 21 ± 1·2 years) had bite force measurements obtained using a custom-made button strain gauge load cell. Masseter and anterior temporalis muscle activities were collected bilaterally using surface EMG sensors whilst participants performed maximal biting and three levels of submaximal biting. Furthermore, a small group (n = 4 females) were retested for reliability purposes. Coefficients of variation and intra-class correlation coefficients showed markedly improved reliability when EMG data were normalised compared to non-normalised. This study shows that jaw muscle EMG may be successfully normalised to a very low bite force. This may open possibilities for comparisons between at-risk sample groups that may otherwise find it difficult to produce maximal bite force values.

Development of the Alcohol Quality of Life Scale (AQoLS): a new patient-reported outcome measure to assess health-related quality of life in alcohol use disorder.

PURPOSE: The development of patient-centred approaches and of reduction in consumption strategies in alcohol use disorder requires giving a larger place to qualitative assessments that are closer to patients' concerns and more clinically relevant than drinking outcomes and generic health-related quality of life instrument. Our purpose was to develop from patients input the Alcohol Quality of Life Scale (AQoLS), a disease-specific measure for alcohol use disorder (AUD). METHODS: Concept elicitation focus groups were conducted with AUD patients in the UK and France. Thematic analysis was used to identify key areas of impact of AUD, and draft items were developed to capture these issues. The draft items underwent expert review to ensure clinical and cross-cultural applicability. Two iterative rounds of cognitive debriefing interviews were conducted with AUD patients in both countries, to assess face and content validity. RESULTS: From focus groups conducted with 38 AUD patients, seven areas of impact emerged, forming the basis for the AQoLS: relationships, activities, looking after self, emotional impact, control, living conditions, and sleep. An initial pool of 90 items was reduced to 50 following the review process. In cognitive interviews, the measure took less than 10 min to complete, and patients reported that items were relevant to their experience. Following Round 1 interviews (n = 16), 14 items were removed because patients felt they were unclear or uneasy to respond to, 2 were combined, 7 were revised, and 4 new items were added. The recall period of 2 weeks was changed to 4 weeks, based on patient comments. Following Round 2 interviews (n = 15), 5 items were removed and 3 were modified to produce the 34-item AQoLS. CONCLUSION: As the only de novo measure of health-related quality of life developed specifically for AUD, the AQoLS offers the potential of increased sensitivity to show the effectiveness of therapeutic interventions from the patient's perspective.

Adapting the Asthma Life Impact Scale (ALIS) for use in Southern European (Italian) and Eastern European (Russian) cultures.

BACKGROUND: The Asthma Life Impact Scale (ALIS) is a disease-specific measure used to assess the quality-of-life of people with asthma. It was developed in the UK and US and has proven to be acceptable to patients, to have good psychometric properties, and to be unidimensional. OBJECTIVE: This paper reports on the adaptation and validation of the ALIS for use in representative Southern European (Italian) and Eastern European (Russian) languages. METHODS: The ALIS was translated for both cultures using the dual-panel process. The newly translated versions were then tested with asthma patients to ensure face and content validity. Psychometric properties of the new language versions were assessed via a test?re-test postal survey conducted in both countries. LIMITATIONS: It is possible that some cultural or language differences still exist between the different language versions. Further research should be undertaken to determine responsiveness. Further studies designed to determine the clinical validity of the Italian ALIS would be valuable. RESULTS: Linguistic nuances were easily resolved during the translation process for both language adaptations. Cognitive debriefing interviews (Russia n=9, male=11.1%, age mean (SD)=55.4 (13.2); Italy n=15, male=66.7%, age mean (SD)=63.5 (11.2)) indicated that the ALIS was easy to read and acceptable to patients. Psychometric testing was conducted on the data (Russia n=61, age mean (SD)=40.7 (15.4); Italy n=71, male=42.6%, age mean (SD)=49.5 (14.1)). The results showed that the new versions of the ALIS were consistent (Russian and Italian Cronbach's alpha=0.92) and reproducible (Russian test-re-test=0.86; Italian test-re-test=0.94). The Italian adaptation showed the expected correlations with the NHP and the Russian adaptation showed strong correlations with the CASIS and CAFS and weak-to-moderate correlations with %FEV1 and %PEF. In both adaptations the ALIS was able to distinguish between participants based on self-reported general health, self-reported severity, and whether or not they were hospitalized in the previous week.