The Acute Effects of Unilateral Ankle Plantar Flexors Static- Stretching on Postural Sway and Gastrocnemius Muscle Activity During Single-Leg Balance Tasks
Bráulio N. Lima1, Paulo R.G. Lucareli2, Willy A. Gomes1, Josinaldo J. Silva1, Andre S. Bley2, Erin H. Hartigan3, Paulo H. Marchetti1,4,
1Department of Human Movement Sciences, Methodist University of Piracicaba, Piracicaba, São Paulo, Brazil 2Department of Rehabilitation Science, Human Motion Analysis Laboratory, Universidade Nove de Julho, São Paulo, Brazil 3Department of Physical Therapy, University of New England, Portland, Maine, USA 4Faculty of Physical Education (YMCA), Sorocaba, São Paulo, Brazil
Paulo H. Marchetti ✉ Methodist University of Piracicaba (UNIMEP), School of Health Sciences, Human Movement Sciences Graduate Program. Rodovia do Açúcar Km 156, Bloco 7, Sala 39, Taquaral. 13423-070 - Piracicaba, SP - Brazil Email: dr.pmarchetti@gmail.com
Received: 24-02-2014 -- Accepted: 25-04-2014 Published (online): 01-09-2014
ABSTRACT
The aim of this study was to investigate the acute effects of unilateral ankle plantar flexors static- stretching on surface electromyography (sEMG) and the center of pressure (COP) during a single-leg balance task in both lower limbs. Fourteen young healthy, non-athletic individuals performed unipodal quiet standing for 30s before and after (stretched limb: immediately post-stretch, 10 and 20 minutes and non-stretched limb: immediately post-stretch) a unilateral ankle plantar flexor static- stretching protocol [6 sets of 45s/15s, 70-90% point of discomfort (POD)]. Postural sway was described using the COP area, COP speed (antero-posterior and medio-lateral directions) and COP frequency (antero-posterior and medio-lateral directions). Surface EMG (EMG integral [IEMG] and Median frequency[FM]) was used to describe the muscular activity of gastrocnemius lateralis. Ankle dorsiflexion passive range of motion increased in the stretched limb before and after the static-stretching protocol (mean ± SD: 15.0° ± 6.0 and 21.5° ± 7.0 [p < 0.001]). COP area and IEMG increased in the stretch limb between pre-stretching and immediately post-stretching (p = 0.015 and p = 0.036, respectively). In conclusion, our static- stretching protocol effectively increased passive ankle ROM. The increased ROM appears to increase postural sway and muscle activity; however these finding were only a temporary or transient effect.
Key words:
Balance, postural stability, stabilometry, motor control
Key Points
The postural control can be affected by static- stretching protocol.
The lateral gastrocnemius muscle action was increased after the static- stretching protocol.
The static- stretching effects remain for less than 10 minutes.
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The Acute Effects of Unilateral Ankle Plantar Flexors Static- Stretching on Postural Sway and Gastrocnemius Muscle Activity During Single-Leg Balance Tasks
Bráulio N. Lima, Paulo R.G. Lucareli, Willy A. Gomes, Josinaldo J. Silva, Andre S. Bley, Erin H. Hartigan, Paulo H. Marchetti
