Evolution of Chewing Force in Geriatric Edentulous Patients

Objective The aim of this study was to assess the evolution of chewing force in edentulous geriatric patients rehabilitated with complete dentures. Chewing function is compromised in individuals who lose all their teeth, as well as in those with complete dentures. The maintenance and recovery of the chewing function in these patients require replacement of the lost natural teeth. Materials and Methods In this study, the chewing force was evaluated by electromyographic analysis of the temporalis and masseter muscle endings in 120 patients with old and new bimaxillary complete dentures. Results Replacement of complete dentures was shown to improve stability, retention, occlusion, and support of the prosthesis. All jaw movements were evaluated using electromyography to assess the evolution of chewing force with and without occlusal adjustment, identify premature contact points, identify occlusal interference, respect the balanced occlusal scheme, and assess the increase in muscle strength. This study found that muscle strength in patients with prosthesis without occlusal adjustment was 527.1 N but was higher for prostheses with occlusal adjustment at 614.7 N, and this strength of 614.7 N was maintained after 1 month of control. Conclusion The chewing force evolved in patients with complete dentures, and an increase was observed when occlusal adjustment was performed.

Electromyographic Analysis of Exercises on a Gymnastic Horse and a Walking Horse: A Pilot Study

In studies testing the effect of hippotherapy on the human body, no one has yet compared the involvement of the same specific muscles in exercises on a gymnastic (pommel) horse vs. a walking horse. To improve the correct riding seat and to compare the differences in electromyographic activity, we conducted an experimental study to measure the activity of selected muscles on a set of probands of both sexes during three exercises on a gymnastic horse vs. a walking horse. We measured the activity of eight selected muscles, expressed as the percentage value of the maximal voluntary contraction. Maximal voluntary contraction of each muscle was electromyographically measured using Janda’s strength muscle test. These values were used as a standard for values obtained from exercising on a gymnastic horse and a walking horse. The effect of the studied factors was tested by analysis of variance. The muscle activity was statistically significantly affected by the studied factors. It was higher when riding a living horse than a gymnastic horse and in females compared to males. Although the exercises on a gymnastic horse generated lower muscle activity than those on a walking horse, there was a variation among individual muscles that justified further study.

Trunk Muscle Activation Patterns During Standing Turns in Patients With Stroke: An Electromyographic Analysis

Recent evidence indicates that turning difficulty may correlate with trunk control; however, surface electromyography has not been used to explore trunk muscle activity during turning after stroke. This study investigated trunk muscle activation patterns during standing turns in healthy controls (HCs) and patients with stroke with turning difficulty (TD) and no TD (NTD). The participants with stroke were divided into two groups according to the 180° turning duration and number of steps to determine the presence of TD. The activation patterns of the bilateral external oblique and erector spinae muscles of all the participants were recorded during 90° standing turns. A total of 14 HCs, 14 patients with TD, and 14 patients with NTD were recruited. The duration and number of steps in the turning of the TD group were greater than those of the HCs, independent of the turning direction. However, the NTD group had a significantly longer turning duration than did the HC group only toward the paretic side. Their performance was similar when turning toward the non-paretic side; this result is consistent with electromyographic findings. Both TD and NTD groups demonstrated increased amplitudes of trunk muscles compared with the HC groups. Their trunk muscles failed to maintain consistent amplitudes during the entire movement of standing turns in the direction that they required more time or steps to turn toward (i.e., turning in either direction for the TD group and turning toward the paretic side for the NTD group). Patients with stroke had augmented activation of trunk muscles during turning. When patients with TD turned toward either direction and when patients with NTD turned toward the paretic side, the flexible adaptations and selective actions of trunk muscles observed in the HCs were absent. Such distinct activation patterns during turning may contribute to poor turning performance and elevate the risk of falling. Our findings provide insights into the contribution and importance of trunk muscles during turning and the association with TD after stroke. These findings may help guide the development of more effective rehabilitation therapies that target specific muscles for those with TD.

Influence of age on postural control during dual task: a centre of pressure motion and electromyographic analysis

Background Dual task influences postural control. A cognitive task seems to reduce muscle excitation during a postural balance, especially in older adults (OA). Aim The aim of this study is to evaluate the effect of three cognitive tasks on muscle excitation and static postural control in OA and young adults (YA) in an upright posture maintenance task. Methods 31 YA and 30 OA were evaluated while performing a modified Romberg Test in five different conditions over a force plate: open eyes, closed eyes, spatial-memory brooks’ test, counting backwards aloud test and mental arithmetic task. The surface electromyographic signals of Tibialis anterior (TA), Lateral Gastrocnemius (GL), Peroneus Longus (PL), and Erector Spinae (ES) was acquired with an 8-channel surface electromyographic system. The following variables were computed for both the electromyographic analysis and the posturographic assessment: Root mean square (RMS), centre of pressure (CoP) excursion (Path) and velocity, sway area, RMS of the CoP Path and 50%, 95% of the power frequency. Mixed ANOVA was used to detect differences with group membership as factor between and type of task as within. The analysis was performed on the differences between each condition from OE. Results An interaction effect was found for Log (logarithmic) Sway Area. A main effect for task emerged on all posturographic variables except Log 95% frequencies and for Log PL and ES RMS. A main effect for group was never detected. Discussion and conclusion This study indicates a facilitating effect of mental secondary task on posturographic variables. Non-silent secondary task causes increase in ES and TA muscle activation and a worsening in static postural control performance.