Attentional Focus in Exercise, Chronic Ankle Instability, Muscle Activation, Neuromuscular Function, Postural Control, Unilateral Ankle Sprain
Conditions
Brief summary
This study investigates the acute effects of single-leg squat exercises conducted under different attentional focus strategies (internal, external, and no focus) on plantar pressure distribution and posterior chain muscle activation in individuals with a history of unilateral ankle sprain. The study aims to determine whether external focus improves neuromuscular efficiency and postural control compared to internal or no attentional focus.
Detailed description
Unilateral ankle sprain is a common condition that compromises proprioception and neuromuscular control, often leading to chronic ankle instability. This randomized crossover trial examines the impact of attentional focus strategies during single-leg squats on surface electromyography (sEMG) activity of posterior chain muscles (gluteus medius, biceps femoris, lateral gastrocnemius, and peroneus) and plantar pressure parameters (COP path length and ellipse area) using pedobarographic analysis. Results may guide rehabilitation protocols by integrating cognitive-motor strategies for improved stability and performance.
Interventions
OTHERSingle-Leg Squat with Internal Focus Intervention
Administration: Participants were instructed to focus on specific muscular or joint movements during single-leg squats (3 sets of 8 repetitions on the affected side, 1-minute rest between sets). Verbal cues included contract your glutes or keep your knee aligned. Data Collected: Surface EMG (Gluteus Medius, Biceps Femoris, Lateral Gastrocnemius, Peroneus) and pedobarographic parameters.
OTHERExternal Focus Intervention
Administration: Participants were instructed to focus on the environmental effects of single-leg squats (3 sets of 8 repetitions on the affected side, 1-minute rest between sets). Verbal cues included push against the floor or drive your foot downward. Data Collected: Surface EMG (Gluteus Medius, Biceps Femoris, Lateral Gastrocnemius, Peroneus) and pedobarographic parameters.
OTHERNo Focus Intervention
Administration: Participants performed single-leg squats naturally without specific attentional instructions (3 sets of 8 repetitions on the affected side, 1-minute rest between sets). Data Collected: Surface EMG (Gluteus Medius, Biceps Femoris, Lateral Gastrocnemius, Peroneus) and pedobarographic parameters.
Sponsors
Ankara Yildirim Beyazıt University
Study design
Allocation
NON_RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
SINGLE (Outcomes Assessor)
Masking description
Although participants and intervention providers were not masked due to the nature of attentional focus instructions, the outcomes assessor was blinded to the type of attentional focus condition applied during each trial. The assessor responsible for analyzing the sEMG and pedobarographic data was not present during exercise implementation and was unaware of the group assignments. Data files were coded and randomized before analysis to minimize detection bias and ensure objective evaluation.
Intervention model description
This study uses a randomized crossover design in which all participants undergo each of the three intervention conditions-internal focus, external focus, and no attentional focus-during the single-leg squat exercise. The order of the conditions is randomized for each participant to reduce sequence and carryover effects. A washout period of 48 hours is maintained between each condition to minimize residual neuromuscular effects. This within-subject design allows for direct comparison of attentional focus strategies on posterior chain muscle activation and plantar pressure parameters.
Eligibility
Sex/Gender
ALL
Age
18 Years to 25 Years
Healthy volunteers
No
Inclusion criteria
* Healthy individuals aged approximately 18-25 years * History of unilateral ankle sprain * Ability to perform single-leg squat exercises * Willingness to provide written informed consent
Exclusion criteria
* Acute musculoskeletal injuries preventing participation * Neurological or neuromuscular impairments * Uncorrected visual impairments * Recent surgery or conditions precluding safe exercise
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Muscle Activation (%MVIC) | Immediately post-intervention in a single session. | Measured via sEMG for Gluteus Medius, Biceps Femoris, Lateral Gastrocnemius, and Peroneus muscles during single-leg squats under each attentional focus condition. |
| Center of Pressure (COP) Path Length | Immediately post-intervention in a single session. | Postural control was assessed immediately after each intervention using a pedobarographic platform. Participants stood barefoot on the affected leg for 30 seconds in a standardized posture (hands on hips, eyes open). The primary outcome in this measure is the COP path length, which represents the total displacement of the pressure center during the trial. Longer COP path lengths indicate greater postural instability. Data were sampled at 100 Hz and analyzed using standardized software to evaluate the immediate effects of attentional focus strategies on postural stability. |
| COP Ellipse Area | Immediately post-intervention, in a single session. | In the same testing conditions as described above, the COP ellipse area was measured. This reflects the 95% confidence area of sway, providing a spatial measure of postural control. Larger ellipse areas denote impaired balance and increased sway. This variable was computed using pedobarographic data sampled at 100 Hz and processed with standardized software. |
Countries
Turkey (Türkiye)
Outcome results
None listed