Stabilometric response during single-leg stance after lower limb muscle fatigue

Abstract

| Objective:This study sought to analyze the effect of muscle fatigue induced by active isotonic resistance training at a moderate intensity by measuring the knee extension motion during the stabilometric response in a single-leg stance among healthy university students who perform resistance training on a regular basis. Method: Eleven healthy university students were subjected to a one-repetition maximum (1RM) test. In addition, stabilometric assessment was performed before and after the intervention and consisted of a muscle fatiguing protocol, in which knee extension was selected as the fatiguing task. The Shapiro-Wilk test was used to investigate the normality of the data, and the Wilcoxon test was used to compare the stabilometric parameters before and after induction of muscle fatigue, at a significance level of p≤0.05. Descriptive statistics were used in the analysis of the volunteers' age, height, body mass, and body mass index (BMI). Results: The sample population was 23.1±2.7 years of age, averaged 1.79.2±0.07 m in height and 75.6±8.0 Kg in weight, and had a BMI of 23.27±3.71 Kg.m -2 . The volunteers performed exercises 3.36±1.12 days/week and achieved a load of 124.54±22.07 Kg on 1RM and 74.72±13.24 Kg on 60% 1RM. The center of pressure (CoP) oscillation on the mediolateral plane before and after fatigue induction was 2.89±0.89 mm and 4.09±0.59 mm, respectively, while the corresponding values on the anteroposterior plane were 2.5±2.2 mm and 4.09±2.26 mm, respectively. The CoP oscillation amplitude on the anteroposterior and mediolateral planes exhibited a significant difference before and after fatigue induction (p=0.04 and p=0.05, respectively). Conclusions: The present study showed that muscle fatigue affects postural control, particularly with the mediolateral and anteroposterior CoP excursion.Keywords: rehabilitation; muscle fatigue; exercise; postural balance. HOW TO CITE THIS ARTICLEBruniera CAV, Rogério FRPG, Rodacki ALF. Stabilometric response during single-leg stance after lower limb muscle fatigue. Braz J Phys Ther. 2013 Sept-Oct; 17(5):464-469. http://dx

Fadiga dos músculos extensores do punho diminui a força de preensão palmar

“…The fatigue protocol consisted in the performance of flexion and extension movements of the wrist in the maximum range, with the elbow in extension (Figure 1), with 75% of 1-MR load, preset to every volunteer, associated with the use of a metronome with frequency of 50 bpm, being interrupted when the volunteer was unable to maintain the frequency in two consecutive or three alternate movements or failed to perform the maximum range 29,30 . For the calculation of MR and fatigue, shin guards were used (0.5; 1.0, 2.0 and 5.0 Kg) adapted to a chain and attached to a tether, which was positioned on the back of volunteers' wrist.…”

Displacement of Centre of Pressure during Rehabilitation Exercise in Adolescent Idiopathic Scoliosis Patients

“…Moreover, AIS is included into the category of pathologies that could affect postural control and balance as well and indirectly modifies the center of mass (COM) displacement [6]. In fact, the common spatial position of the body segment, especially the head and trunk, can be modified by scoliosis [7], or by the involuntary arrangement of the subjects [8] who alter posture to counteract scoliosis [9], because of the spontaneous correction of the control system to keep the eyes aligned with the horizontal line. For these reasons, spinal alignment falls further altering scoliotic curves.…”

“…In point of this, the COP displacement is used to estimate the sway of the COM during physical activities such as everyday life gestures or sport-specific performance [11,19]. COP sway, actually, is considered to assess static posture [20], the effects of different dental occlusion conditions [13,21,22], the outcomes after session of physical therapy [6] or in consequence of fatiguing [7]. In particular, in AIS subjects, COP sway assessment could ameliorate the general evaluation of the motor control of the subjects and then improve the personalized exercise routine.…”