Electromyographic activity of rectus abdominis muscles during dynamic Pilates abdominal exercises

Electromyographic Activation and Co-contraction of the Thigh Muscles During Pilates Exercises on the Wunda Chair

Objective

The aim of the present study was to investigate whether Pilates exercises on the Wunda chair (Going Up Front and Mountain Climb) activate the muscles rectus femoris (RF) and biceps femoris (BF) in 2 situations (foot on the pedal and foot on the seat).

Methods

Sixteen young female Pilates practitioners (18-35 years old) participated in this study. The muscles of their right leg were then submitted to electromyography analysis during the exercises.

Results

Significant differences were found for the RF muscle (maximal voluntary isometric contraction [%MVIC]), which was assessed and compared between the 2 exercises (Going Up Front and Mountain Climb: F = 9.83; P = .03; np2 = 0.14); 2 conditions (foot on the pedal and foot on the seat: F = 40.02; P < .001; np2 = 0.90) and interactions (F = 14.49; P < .001; np2 = 0.20) and for BF muscle (%MVIC) in the comparisons between the 2 conditions (foot on the pedal and foot on the seat: F = 27.5; P < .001; np2 = 0.82) and interactions (F = 12.57; P < .001; np2 = 0.17). The percentage of cocontraction presented the significant difference in the comparisons between the 2 conditions (foot on the pedal and foot on the seat: F = 24.07; P < .001; np2 = 0.286).

Conclusion

Both Pilates exercises activated the thigh core muscles in the moderate and high categories. The highest percentage of cocontraction levels were presented when the foot was resting on the pedal.

People with chronic low back pain display spatial alterations in high-density surface EMG-torque oscillations

We quantified the relationship between spatial oscillations in surface electromyographic (sEMG) activity and trunk-extension torque in individuals with and without chronic low back pain (CLBP), during two submaximal isometric lumbar extension tasks at 20% and 50% of their maximal voluntary torque. High-density sEMG (HDsEMG) signals were recorded from the lumbar erector spinae (ES) with a 64-electrode grid, and torque signals were recorded with an isokinetic dynamometer. Coherence and cross-correlation analyses were applied between the filtered interference HDsEMG and torque signals for each submaximal contraction. Principal component analysis was used to reduce dimensionality of HDsEMG data and improve the HDsEMG-based torque estimation. sEMG-torque coherence was quantified in the δ(0–5 Hz) frequency bandwidth. Regional differences in sEMG-torque coherence were also evaluated by creating topographical coherence maps. sEMG-torque coherence in the δ band and sEMG-torque cross-correlation increased with the increase in torque in the controls but not in the CLBP group (p = 0.018, p = 0.030 respectively). As torque increased, the CLBP group increased sEMG-torque coherence in more cranial ES regions, while the opposite was observed for the controls (p = 0.043). Individuals with CLBP show reductions in sEMG-torque relationships possibly due to the use of compensatory strategies and regional adjustments of ES-sEMG oscillatory activity.

Co-contraction of the core muscles during Pilates exercise on the Wunda Chair

BACKGROUND

The co-contraction of the core muscles has been reported as the key mechanism towards spinal stability. Classic Pilates exercises aimed at these muscles are known to improve the stability and strength of the trunk without damaging the deep structures of the spine.

OBJECTIVE

To evaluate the co-contraction of the mobilizing (rectus abdominis; longissimus) and stabilizing (multifidus; internal oblique) trunk muscles during Pilates exercises - going up front, mountain climber, and swan.

METHODS

Sixteen women, all Pilates practitioners, participated in the study. The stabilizing and mobilizing muscles of the trunk (right side) were submitted to electromyography to calculate the percentage of co-contraction during the exercises. One-way repeated measures analysis of variance (ANOVA) was used to verify the difference in %COCON between stabilizers and mobilizers among the three exercises. The post-hoc Bonferroni test (P< 0.01) was applied when necessary. The paired t-test (P< 0.01) was used to verify the difference in %COCON between stabilizers and mobilizers separately for each exercise.

RESULTS

The co-contraction values of the stabilizers were higher than those of the mobilizers for all exercises. The going up front (stabilizers) and the swan (mobilizers) exercises showed the highest %COCON values.

CONCLUSIONS

The Pilates method is effective for either rehabilitating pathologies or training the trunk muscles in healthy individuals and athletes.

Spatial distribution of lumbar erector spinae muscle activity in individuals with and without chronic low back pain during a dynamic isokinetic fatiguing task

BACKGROUND

Individuals with chronic low back pain (CLBP) commonly present with increased trunk muscle fatigability; typically assessed as reduced time to task failure during non-functional isometric contractions. Less is known about the specific neuromuscular responses of individuals with CLBP during dynamic fatiguing tasks. We investigate the regional alteration in muscle activation and peak torque exertion during a dynamic isokinetic fatiguing task in individuals with and without CLBP.

METHODS

Electromyography (EMG) was acquired from the lumbar erector spinae unilaterally of 11 asymptomatic controls and 12 individuals with CLBP, using high-density EMG (13 × 5 grid of electrodes). Seated in an isokinetic dynamometer, participants performed continuous cyclic trunk flexion-extension at 60^o/s until volitional exhaustion.

FINDINGS

Similar levels of muscle activation and number of repetitions were observed for both groups (p > 0.05). However, the CLBP group exerted lower levels of peak torque for both flexion and extension moments (p < 0.05). The centre of lumbar erector spinae activity was shifted cranially in the CLBP group throughout the task (p < 0.05), while the control participants showed a more homogenous distribution of muscle activity.

INTERPRETATION

People with CLBP displayed altered and potentially less efficient activation of their lumbar erector spinae during a dynamic fatiguing task. Future studies should consider using high-density EMG biofeedback to optimise the spatial activation of the paraspinal musculature in people with low back pain (LBP).

Core muscle activation during Pilates exercises on the Wunda chair

OBJETIVES

The Pilates method, developed by Joseph Pilates (1886-1967), has been widely used to improve trunk stability, muscle flexibility and strength, physical fitness, and body awareness. To measure the electromyography of four trunk muscles during three Pilates exercises carried out of the wunda chair. DESING: cross-section study.

METHODS

Sixteen women participated in this study with a height and body weight of 1.64 ± 0.04 m and 58.7 ± 7.4 kg, respectively, and a mean age of 27.6 ± 3.7 years. Rectus abdominis (RA), internal oblique (IO), longissimus (LO), and multifidus (MU) muscles was evaluated by electromyographic (EMG) tests activity during three Pilates exercises: going up front (GF), mountain climb (MC), and swan (SW). EMG was normalized and expressed in the time domain, by the RMS.

RESULTS

The highest EMG values concerning the four muscles were observed for the MC exercise, followed by GF and SW (ANOVA: p = 0.0001, p = 0.04, p = 0.0002, and p = 0.0013, respectively). Our results show that the three Pilates exercises could recruit all the muscles, with a moderate activity intensity. The ANOVA; p < 0.05 showed significant difference between the muscles, concerning SW (p = 0.0002).

CONCLUSION

Our results show that the three Pilates exercises could recruit all the muscles, with a moderate activity intensity.

Análise eletromiográfica de músculos do tronco e pelve durante o leg circle no solo e com molas no Cadillac

RESUMO O objetivo do estudo é investigar, através da EMG, se é possível alterar a exigência dos músculos estabilizadores do tronco e da pelve, executando o exercício Leg Circle no solo e com diferentes posicionamentos das molas no Cadillac. Treze instrutoras praticantes de Pilates por no mínimo seis meses e sem dor realizaram 10 repetições do exercício Leg Circle em três situações: (1) Solo; (2) Molas altas (MA); (3) Molas médias (MM). Foram obtidos dados de EMG dos músculos oblíquo interno do abdômen/transverso do abdômen (OI/TS), oblíquo externo do abdômen (OE), reto abdominal (RA) e multífidos (MU) apresentados em percentual da CIVM. As comparações foram realizadas através da ANOVA de medidas repetidas (α=0,05). Todos os músculos sofreram influência do posicionamento da mola. No solo, as maiores ativações ocorreram nos músculos RA e OE, enquanto nas execuções realizadas com molas, os músculos mais recrutados foram OI/TS (MM) e MU (MA). Os músculos RA e OE não obtiveram diferenças entre as situações MA e MM. A execução do exercício Leg Circle no solo e com molas gera alterações no recrutamento dos músculos avaliados. Observa-se também que, ao analisar o exercício realizado no Cadillac entre molas altas e molas médias, houve diferença apenas para os músculos OI/TS e MU.

Electromyographic evaluation of trunk core muscles during Pilates exercise on different supporting bases

OBJECTIVE

To evaluate the electromyographic (EMG) activity of the rectus abdominis (RA) and internal oblique (IO) muscles during Pilates exercise on different trunk supporting bases.

METHODS

Sixteen female Pilates practitioners participated in the study. EMG of the RA and OI muscles was evaluated during the double leg stretch (DLS) exercise on three different supporting bases - mat, long box, and short box. Trunk stability varies according to the size and type of the base. To normalize the data, the RMS value (EMG) obtained during the DLS exercise was divided by the RMS value from the torque test - the maximal voluntary isometric contraction (MVIC) - and multiplied by 100 (%MVIC). One-way repeated-measured analysis of variance (ANOVA) and Bonferroni tests were used to compare data concerning the supporting bases and Student t-test regarding the muscles (p < 0.05).

RESULTS

The comparison among the bases involving each muscle - RA or IO (p < 0.05) - showed significant difference (%MVIC) between the mat and the short box. No significant difference was observed between the muscles concerning the exercise on the mat (p = 0.9266), on the long box (p = 0.5113) and on the short box (p = 0.2972).

CONCLUSION

The short box increased the activity of the rectus abdominis and internal oblique muscles during exercise. The DLS exercise was able to challenge the stability of the trunk and thus recruit its stabilizer and mobilizer muscles at the same intensity.

Neuromuscular efficiency of the multifidus muscle in pilates practitioners and non-practitioners

BACKGROUND

Pilates exercises help stabilize the vertebral segments by recruiting the abdominal and spinal muscles. Pilates training may increase joint stability and improve neuromuscular efficiency (NME).

OBJECTIVE

This study aimed to evaluate NME of the multifidus (MU) muscle through electromyography (EMG) analysis and torque test, applied to practitioners and non-practitioners of Pilates.

METHODS

Participants included thirty women: Pilates practitioners (n = 15) and non-practitioners (n = 15). They were tested for trunk extension. Their right and left MU muscles were submitted to EMG to estimate NME. Results concerning torque, EMG, and NME from all participants were compared.

RESULTS

Statistical analysis concerning isometric torque peak (p = 0.0275) and NME (p = 0.0062) showed significant difference (Student t test; p < 0.05) between practitioners and control. No significant difference (p = 0.3387) in EMG was observed.

CONCLUSION

Our results suggest Pilates exercises is effective in training spinal muscles to improve NME in women.