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SEMG investigation of lower limb and abdominal muscles during progressions of a core stability exercise

Jones, Karen, Adcock, Sophie and McCarthy, Holly 2007. SEMG investigation of lower limb and abdominal muscles during progressions of a core stability exercise. Presented at: Physiotherapy Research Society Spring Meeting, Cardiff, Wales, UK, 28 March 2007.

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Background: The loss of selective muscle activity in the trunk is a fundamental problem experienced by patients after a Cerebral Vascular Accident (CVA) (Davies, 1990). The return of trunk control is vital for the performance of activities of daily living and hence is a key focus in the rehabilitation of CVA patients (De Seze et al, 2001). The posterior pelvic tilt exercise (PPTE) is commonly used during neurological rehabilitation to retrain the trunk muscles and improve core stability. Progressions of this exercise are commonly used in order to advance the rehabilitation program and enable the patient to achieve maximal independence (Wade, 1992). Two of the progressions commonly used, involve the performance of the basic exercise together with a unilateral leg drop out or a bilateral arm raise. Despite their frequent use, there is no evidence to either support or refute their effectiveness from a neurological perspective. Furthermore, in patients with poor core stability it is often necessary for them to use limb compensation/fixation in order to function. However, this has also not been evaluated in the evidence. Considering the gaps in research, this study will investigate the difference in average surface electromyography (SEMG) muscle activity of internal oblique (IO) and external oblique (EO) when performing a baseline PPTE compared with i) a PPTE with a bilateral arm raise and ii) a PPTE with a unilateral leg drop out. SEMG will also simultaneously record activity in Quadriceps and hamstrings during the three conditions. Objectives: The aims of the study are to 1)examine whether the progression exercises increase mean abdominal muscle activity compared with the basic PPTE and therefore justify its use as a progression in the clinical setting. 2) evaluate the compensatory/ fixation activity of Quadriceps and hamstrings during all three conditions. Methodology: A healthy subject group consisting of 19 females and 3males ranging from 20 to 26 years (mean 21.5 years ±1.57), from Cardiff University, volunteered to take part in this study. They signed a consent form after reading an information sheet and following a 24hour contemplation time. A health questionnaire was completed and this acted as an exclusion criteria (eg. Present back pain, pregnancy, recent surgery). The research protocol was standardised and SEMG was used to measure the muscle activity of IO and EO whilst each subject performed all three conditions i) baseline PPTE ii) PPTE plus unilateral leg drop out iii) PPTE plus bilateral arm raise These were repeated three times with 30 seconds between recordings to reduce the effects of fatigue. To minimise the order effect, 11 subjects performed the PPTE followed by the PPTE with the progressions and visa versa for the other 11 subjects. The SEMG procedure was standardised for electrode placement, skin preparation and instructions. The SEMG recording was normalised against a maximal voluntary contraction for each muscle and then averaged for all three conditions over a duration of 10 seconds. Statistical analysis used a one way ANOVA with a post hoc t test. Significance set at p=<0.05. Results: 1) abdo data – REO – (p=0.034), LIO (0.051/0.071). RIO / LEO none statistically sig 2) leg data – R hamstring ONLY - (p=0.000) between unilateral leg drop out and bilateral arm raise. Due to performance of Right leg drop – therefore right hamstring switches off during drop making statistical sig when it is recruited for arm raise.L hamstrings / R Quad/ L Quad – not significant – could imply that legs not used to fix in this population. However graph implies that with harder stability ex (arm raise) hamstring activity is increased. Conclusion: The average bilateral SEMG muscle activity of IO and EO was found to be significantly higher when performing the progression compared with the basic PPTE. Therefore, the study indicates that the PPTE is more effective when performed with a bilateral arm raise and could be used to retrain IO and EO in healthy subjects. Consequently, the use of these exercises during the re-training of core stability is justified. It is essential however, that further research is carried out in order to support these findings. It is necessary that this future research be conducted on a sample of neurologically impaired patients, with the purpose of fully understanding the effects of the progression of the PPTE in the neurological setting.

Item Type: Conference or Workshop Item (Lecture)
Date Type: Completion
Status: Unpublished
Schools: Healthcare Sciences
Subjects: R Medicine > RM Therapeutics. Pharmacology
Last Modified: 05 Jan 2018 20:55

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