Electromyographic Muscle Activity in Curl-Up Exercises With Different Positions of Upper and Lower Extremities

Abstract

The purpose of the study was to evaluate the electromyographic (EMG) activity of muscles in curl-up exercises depending on the position of the upper and lower extremities. From the perspective of biomechanics, different positions of the extremities result in shifting the center of gravity and changing muscular loads in abdominal strength exercises. The subjects of the research were 3 healthy students (body mass 53-56 kg and height 163-165 cm) with no history of low back pain or abdominal surgery. Subjects completed 18 trials for each of the 9 exercises (static curl-up with 3 positions of the upper and 3 position of the lower extremities). The same experiment with the same subjects was conducted on the next day. The EMG activity of rectus abdominis (RA), erector spinae (ES), and quadriceps femoris-long head (rectus femoris [RF]) was examined during the exercises. The surface electrical activity was recorded for the right and left sides of each muscle. The raw data for each muscle were rectified and integrated. The statistical analysis showed that changing the position of upper extremities in the examined exercises affects the EMG activity of RA and ES but does not significantly affect the EMG activity of RF. Additionally, it was found that curl-up exercises with the upper extremities extended behind the head and the lower extremities flexed at 90° in the hip and knee joints involve RA with the greatest intensity, whereas curl-up exercises with the upper extremities extended along the trunk and the lower extremities flexed at 90° in the hip and knee joints involve RA with the lowest intensity.

External torque as a factor to modify load in abdominal curl-up exercises

“…The idea adopted in the study consists of increasing the load to the muscles through changing the external torque. It was supported by previous results where contribution of body trunk flexors and hip extensors in abdominal exercises performed in different angular positions of the lower and upper limbs was examined [16,17]. These studies have found that the change in position of the upper and lower limbs (change in length of the lever arm) and the change in the muscle torque (through changing the angle of the joint) cause a change in abdominal muscle activity.…”

Effects of non-paretic arm exercises using a tubing band on abdominal muscle activity in stroke patients

“…In early studies, Arokoski, Valta, Airaksinen, and Kankaanpää (2001) reported the effects on abdominal muscle activity during the performance of upper-limb exercises; the activation patterns of the abdominal muscles were affected by the direction of restricted upper-limb movements. Other researchers have also reported that changes in position of the upper extremities enriched curl-up exercises due to change in abdominal load (Rutkowska-Kucharska, & Szpala, 2010). However, these exercises are difficult to use to strengthen abdominal muscles in stroke patients because many stroke patients cannot readily use the paretic upper limb.…”

Análise eletromiográfica de músculos do abdome e reto femoral em exercícios abdominais com e sem superfície instável

“…Em função disso, investigações têm sido conduzidas a fim de determinar a maneira mais eficiente e correta de se realizar exercícios abdominais, principalmente por meio da eletromiografia de superfície [6][7][8][9][10] . Esta, segundo Basmajian e De Luca 11 , é o estudo da função muscular a partir da averiguação do sinal elétrico que emana do músculo.…”