Effects of Novel Inverted Rocker Orthoses for First Metatarsophalangeal Joint on Gastrocnemius Muscle Electromyographic Activity during Running: A Cross-Sectional Pilot Study

Abstract

Background: The mobility of the first metatarsophalangeal joint (I MPTJ) has been related to the proper windlass mechanism and the triceps surae during the heel-off phase of running gait; the orthopedic treatment of the I MPTJ restriction has been made with typical Morton extension orthoses (TMEO). Nowadays it is unclear what effects TMEO or the novel inverted rocker orthoses (NIRO) have on the EMG activity of triceps surae during running. Objective: To compare the TMEO effects versus NIRO on EMG triceps surae on medialis and lateralis gastrocnemius activity during running. Study design: A cross-sectional pilot study. Methods: 21 healthy, recreational runners were enrolled in the present research (mean age 31.41 ± 4.33) to run on a treadmill at 9 km/h using aleatory NIRO of 6 mm, NIRO of 8 mm, TMEO of 6 mm, TMEO of 8 mm, and sports shoes only (SO), while the muscular EMG of medial and lateral gastrocnemius activity during 30 s was recorded. Statistical intraclass correlation coefficient (ICC) to test reliability was calculated and the Wilcoxon test of all five different situations were tested. Results: The reliability of values was almost perfect. Data showed that the gastrocnemius lateralis increased its EMG activity between SO vs. NIRO-8 mm (22.27 ± 2.51 vs. 25.96 ± 4.68 mV, p < 0.05) and SO vs. TMEO-6mm (22.27 ± 2.51 vs. 24.72 ± 5.08 mV, p < 0.05). Regarding gastrocnemius medialis, values showed an EMG notable increase in activity between SO vs. NIRO-6mm (22.93 ± 2.1 vs. 26.44 ± 3.63, p < 0.001), vs. NIRO-8mm (28.89 ± 3.6, p < 0.001), and vs. TMEO-6mm (25.12 ± 3.51, p < 0.05). Conclusions: Both TMEO and NIRO have shown an increased EMG of the lateralis and medialis gastrocnemius muscles activity during a full running cycle gait. Clinicians should take into account the present evidence when they want to treat I MTPJ restriction with orthoses, and consider the inherent triceps surae muscular cost relative to running economy.

Assessment of a New Lateral Cushioned Casting Orthosis: Effects on Peroneus Longus Muscle Electromyographic Activity During Running

“… 8 , 12 The total amount of the decreases reported in the present work was larger when wearing CMW than NSO perhaps because of the more powerful effect of hard CMW on PL tendon strain and its muscle belly relief than that obtained via cushioning NSO. As has been reported previously with running shoes 29 and novel orthoses, 34 it seems that wearing cushioning (vs hard materials) may induce more muscle activity in order to balance the foot during running gait.…”

“…Sample size estimations to carry out the present study were assessed by the statistics unit at the Complutense University of Madrid, which used SPSS Version19.0 (IBM Corp) software to compare the EMG changes in PL activity during running among the 7 different study conditions. Data on the gastrocnemius lateralis in a previous study 34 showed a mean EMG value of 25.96 ± 4.68 mV for a novel orthosis compared with 22.27 ± 2.51 mV ( P < .05) for typical running shoes. Considering a statistical power of 80%, β = 20%, a 95% confidence interval, and α = .05, a total of 30 participants were needed to perform this study.…”

“…The EMG values for both CMW and NSO were lower than those for NRS during the running test. The wide variability among related studies in sample size and type (eg, poor participant recruitment 8 , 15 , 30 or participants with pathology 8 , 31 – 33 vs healthy 1 , 17 participants) and experimental conditions (eg, walking 8 , 30 , 31 , 34 – 36 vs running 2 , 14 , 21 and intramuscular electrode 32 , 34 vs surface electrode 2 , 17 , 22 , 39 assessments of PL activity) renders any meaningful comparison between results difficult.…”

“…A motorized treadmill (Domyos T520) was used for the running test. Participants performed a trial run for 3 minutes at 5.7 km/h to become acclimatized to the treadmill 34 and to minimize external variables (eg, different floor slopes or running speeds). Then, the running test was performed at 9 km/h 36 under each of the 7 conditions (NRS, NSO 3mm , NSO 6mm , NSO 9mm , CMW 3mm , CMW 6mm , and CMW 9mm ), randomly performed on the same day.…”

Foot Orthotics with Morton's Extension doesn't Affects the Forces inside First Metatarsophalangeal Joint in Osteoarthritis Pathology.

“…Our surprising results could mean that following reach the joint stop movement through ME´s thickness, the pulling force needed to perform the Jack´s test was the same, regardless of external ME´s restrictions. The total amount of dorsal mobility of the rst ray in WRP reported by previous studies was set at 4.9mm 17 , which is higher than that achieved in the ankle dorsi exion position; this is due to the increased tension on the plantar aponeurosis related to the Windlass mechanism 12,18 as it has been shown previously by the intrinsic correlation between rst MPJ and the triceps surae 27,39 . The ME thicknesses used in our experiment were 2, 4, and 8 mm; in our results, the 4-mm ME orthotic produced the greatest tension effort on the rst MPJ, which could be compared with the mobility results of Grady 17 , but without any statistical signi cance.…”