Effects of Two Different Self-Adapted Occlusal Splints on Electromyographic and Force Parameters During Elbow Flexors Isometric Contraction

Abstract

Limonta, E, Arienti, C, Rampichini, S, Venturelli, M, Cè, E, Veicsteinas, A, and Esposito, F. Effects of two different self-adapted occlusal splints on electromyographic and force parameters during elbow flexors isometric contraction. J Strength Cond Res 32(1): 230-236, 2018-The study was aimed at determining the acute effects of 2 types of occlusal splints on maximum isometric strength and fatigue of the elbow flexors muscles. The hypothesis was that splint-induced masticatory muscle repositioning might improve primary muscles recruitment by stretching masticatory muscles especially with the thicker splint. On 9 physically active volunteers with no temporomandibular joint and masticatory muscles disorders, we assessed maximum voluntary contraction (MVC) of the elbow flexors with diurnal (OSD, 1-mm thick) and sport (OSSP, 3-mm thick) splints, and without splint (control, Ctrl). On different days, participants performed 60 seconds of isometric contraction at 100% MVC (100%60s) and 80% MVC contraction until exhaustion (80%exh) under OSD, OSSP, and Ctrl in random order. Time of force output within target (t-target), force distance from target (ΔF), and force coefficient of variation were calculated. Percentage of force decay (ΔFi-Fe) was determined during 100%60s. From the electromyographic (EMG) signal, root mean square (EMG RMS) and mean frequency (EMG MF) were determined. Neuromuscular efficiency (NE) was calculated as the ratio between force and EMG RMS. MVC contraction and NE were significantly higher in OSSP and OSD than in Ctrl. During MVC, EMG MF was significantly lower in both splint conditions, and EMG RMS showed a nonstatistical tendency to lower values under both splint conditions. During 80%exh, t-target was longer in OSD and OSSP (+7.8% and +5.2%, respectively) than in Ctrl. ΔFi-Fe was lower in OSSP than in Ctrl and OSD. These results support the hypothesis of a NE improvement of the elbow flexors possibly induced by acute, splint-induced masticatory muscles repositioning.

Acute Effects of Wearing Bite-Aligning Mouthguards on Muscular Strength, Power, Agility and Quickness in a Trained Population: A Systematic Review

“…All the studies included a within-subject, cross-over design and were specifically developed with athletes who were involved in different sports and standards. Sixteen of these studies [ 2 , 12 , 14 , 15 , 16 , 17 , 18 , 20 , 21 , 23 , 24 , 29 , 33 , 34 , 35 , 36 ] were performed with recreational athletes, nine [ 13 , 19 , 22 , 25 , 26 , 27 , 30 , 31 , 43 ] of them were performed with high-standard athletes and two [ 28 , 32 ] combined both groups. Twenty articles recruited only male participants, [ 2 , 12 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 27 , 28 , 29 , 30 , 32 , 33 , 43 ], one recruited only female participants [ 36 ] and six recruited participants of both sexes [ 13 , 14 ,…”

“…The type of mouthguard also varied among studies. The custom-made type (CMM) was the most used in eighteen studies [ 14 , 15 , 16 , 18 , 19 , 22 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 33 , 34 , 35 , 36 , 43 ], whereas the self-adapted (SAM) type was used in seventeen [ 2 , 12 , 13 , 14 , 15 , 17 , 20 , 21 , 23 , 27 , 28 , 29 , 30 , 31 , 32 , 35 , 36 ], and the standard (STNDM) in two studies [ 19 , 36 ] ( Figure 2 ). Three of these articles [ 19 , 22 , 43 ] used placebo (PLA) mouthguards to blind the information of the mouthguard type.…”

“…Three of these articles [ 19 , 22 , 43 ] used placebo (PLA) mouthguards to blind the information of the mouthguard type. Additionally, a comparison between the use of an oral device (MG) with a nonuse condition (NoMG) was reported in ten studies [ 2 , 12 , 13 , 23 , 24 , 25 , 26 , 31 , 32 , 34 ], while seventeen [ 10 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 27 , 28 , 29 , 30 , 33 , 35 , 43 ] compared more than one type of mouthguard. Overall, from the twenty-seven reviewed studies, sixteen [ 2 , 13 , 14 , 17 , 18 , 22 , 23 , 24 , 25 , 26 , 29 , 30 , 31 , 32 , 34 , 35 ] reported positive effects in some of the variables assessed, whereas two [ 29 , 35 ] reported negative effects.…”

“…Originally, sports mouthguards were designed to minimize the incidence of orofacial injuries through the absorption of the energy during head and mouth trauma [ 1 ]. Besides this preventive role, several studies have investigated the effects of wearing these oral devices on metabolic [ 2 , 3 , 4 , 5 ], ventilatory [ 6 , 7 , 8 , 9 ], functional [ 10 , 11 ] or neuromuscular performance parameters, and this, concretely, has focused on strength [ 2 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 ], power [ 12 , 15 , 16 , 18 , 20 , 21 , 22 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 ], quickness [ 26 , 34 , 35 ] or agility [ 15 , 25 , 36 ]. The potential neuromuscular effects might be attributed to the postural repositionin...…”

Comparing the Effectiveness of Isotonic and Isometric Exercises on Balance and Ability in Patients with Multiple Sclerosis

“…There is an ongoing debate about isotonic and isometric exercise on torque, endurance, fatigue, and strength muscle [13] . Existing evidence suggests both exercises have a similar significance in the muscle's recovery function and strength, while Limonta et al demonstrated that isokinetic training has better results [14] . Therefore, in the present study, we aimed to determine whether a progressive isotonic than the isometric exercise would improve postural ability and balance in MS patients.…”