Herrera E1, Bacca O1, Reina DC1, Delgado-Díaz DC1, Rosa DP1
1Universidad Industrial de Santander, Physical Therapy, Bucaramanga, Colombia
Background: Cryotherapy is applied during the rehabilitation of sports injuries for decreasing the inflammatory response, edema, pain and muscle spasm. However, there is still controversy about using cryotherapy before and during sports practice sessions, because some studies have shown immediate alterations in the muscle physiological properties, affecting muscle activation and performance.
Purpose: To evaluate the immediate and 30min after effect of two cryotherapy modalities on EMG activity of plantar-flexors and dorsiflexors during unipodal balance tests (firm and foam surfaces) with closed eyes, in young and healthy men.
Methods: Randomized single-blinded experimental study. 75 healthy, physically active males (age: 20.1±1.9 y/o; BMI: 22.5±2.7kg/cm2) volunteered to participate being distributed into three groups: Control (CG), Ice Pack (IPG) and Ice-massage (IMG). The cooling was applied for twenty minutes in the calf (15x25cm) of the dominant limb. The CG participants remained in the same position (prone) in a room with controlled temperature (23°C). Three EMG measurements (baseline, immediately and 30min after cryotherapy) on the Tibialis Anterior (TA), Soleus (SO), Medial Gastrocnemius (MG) and Lateral Gastrocnemius (LG) muscles were performed (BTS FREEMG 100), according to SENIAM, in the single leg stance test with closed eyes on firm and foam surfaces (HUMAC® Balance System). Output variables: Root Mean Square (RMS) amplitude (% maximal isometric voluntary contraction/MIVC) and Median Frequency. Explanatory variables: group, time measurement and balance test surface (firm and foam). Shapiro Wilk test to determine normality of the variables and ANCOVA to establish differences between groups were used. All analyses were conducted in Stata 13.0, with alpha set at 0.05.
Results: Immediately after cooling, IPG and IMG decreased the median frequency of plantar-flexors on firm surface with following regression coefficients, respectively: MG: -19.8 and -39.3; LG: -12.6 and -24.3 (p 0.001). These data on foam surface were: MG: -20.4 and -39.9; LG: -11.4 and -22,4, respectively (p 0.001). The IMG increased log RMS amplitude of all muscles in firm surface: TA: 0,3; MG: 0,7; LG: 0,4; SO: 0,4 and LG in foam surface (0.4); p 0.02. The IPG increased RMS amplitude of LG, in both firm (0.4) and foam (0.2) surfaces; p 0.03. Thirty minutes after cryotherapy, differences were found in IMG for LG median frequency (-12.4, p=0.000) on firm surface and MG (-9.7, p=0.02) and LG median frequency (-11.3, p=0.001) on foam surface. The only difference found for IPG was TA median frequency (-12.1, p=0.04) and MG log RMS (-0.2, p=0.03).
Conclusion(s): Cryotherapy reduced the median frequency and increased the RMS amplitude of the plantar-flexors during the balance tests. These effects were more evident for ice-massage, suggesting unlike effects on the muscle recruitment pattern by different cooling modalities. Most changes on the muscle recruitment by cooling are short-lived and return to baseline after thirty minutes' post-cryotherapy.
Implications: The application of cryotherapy within the competition could alter muscle performance and predispose to further injury. It would be advisable to apply cryotherapy at least thirty minutes before the competition. Ice pack, compared to ice-massage, would cause minor deleterious effects on muscle performance.
Keywords: Cryotherapy, electromyography activity, recruitment muscle
Funding acknowledgements: Universidad Industrial de Santander, Colombia.
Purpose: To evaluate the immediate and 30min after effect of two cryotherapy modalities on EMG activity of plantar-flexors and dorsiflexors during unipodal balance tests (firm and foam surfaces) with closed eyes, in young and healthy men.
Methods: Randomized single-blinded experimental study. 75 healthy, physically active males (age: 20.1±1.9 y/o; BMI: 22.5±2.7kg/cm2) volunteered to participate being distributed into three groups: Control (CG), Ice Pack (IPG) and Ice-massage (IMG). The cooling was applied for twenty minutes in the calf (15x25cm) of the dominant limb. The CG participants remained in the same position (prone) in a room with controlled temperature (23°C). Three EMG measurements (baseline, immediately and 30min after cryotherapy) on the Tibialis Anterior (TA), Soleus (SO), Medial Gastrocnemius (MG) and Lateral Gastrocnemius (LG) muscles were performed (BTS FREEMG 100), according to SENIAM, in the single leg stance test with closed eyes on firm and foam surfaces (HUMAC® Balance System). Output variables: Root Mean Square (RMS) amplitude (% maximal isometric voluntary contraction/MIVC) and Median Frequency. Explanatory variables: group, time measurement and balance test surface (firm and foam). Shapiro Wilk test to determine normality of the variables and ANCOVA to establish differences between groups were used. All analyses were conducted in Stata 13.0, with alpha set at 0.05.
Results: Immediately after cooling, IPG and IMG decreased the median frequency of plantar-flexors on firm surface with following regression coefficients, respectively: MG: -19.8 and -39.3; LG: -12.6 and -24.3 (p 0.001). These data on foam surface were: MG: -20.4 and -39.9; LG: -11.4 and -22,4, respectively (p 0.001). The IMG increased log RMS amplitude of all muscles in firm surface: TA: 0,3; MG: 0,7; LG: 0,4; SO: 0,4 and LG in foam surface (0.4); p 0.02. The IPG increased RMS amplitude of LG, in both firm (0.4) and foam (0.2) surfaces; p 0.03. Thirty minutes after cryotherapy, differences were found in IMG for LG median frequency (-12.4, p=0.000) on firm surface and MG (-9.7, p=0.02) and LG median frequency (-11.3, p=0.001) on foam surface. The only difference found for IPG was TA median frequency (-12.1, p=0.04) and MG log RMS (-0.2, p=0.03).
Conclusion(s): Cryotherapy reduced the median frequency and increased the RMS amplitude of the plantar-flexors during the balance tests. These effects were more evident for ice-massage, suggesting unlike effects on the muscle recruitment pattern by different cooling modalities. Most changes on the muscle recruitment by cooling are short-lived and return to baseline after thirty minutes' post-cryotherapy.
Implications: The application of cryotherapy within the competition could alter muscle performance and predispose to further injury. It would be advisable to apply cryotherapy at least thirty minutes before the competition. Ice pack, compared to ice-massage, would cause minor deleterious effects on muscle performance.
Keywords: Cryotherapy, electromyography activity, recruitment muscle
Funding acknowledgements: Universidad Industrial de Santander, Colombia.
Topic: Electrophysical & isothermal agents; Sport & sports injuries
Ethics approval required: Yes
Institution: Universidad Industrial de Santander
Ethics committee: CEINCI-UIS
Ethics number: Act number 21; september 22, 2017
All authors, affiliations and abstracts have been published as submitted.
