Table 4. Summary of which muscle investigated, measured biomechanical parameters and normalization method of each study. Various method for EMG data normalization method were adopted, and clearly described the procedures in most of the included studies. Some relevant biomechanical parameters also measured as secondary outcomes, i.e., stroke length (SL) and stroke frequency (SF) and so on.

Author (Year)	Main Purpose	Swim Test	Muscles Investigated	Biomechanical Parameters	Normalization of EMG Data
Rouard et al (1995)	Co-contraction	4 X 100m FC	Unilateral: Side - Not Mentioned Upper Limbs: BB, TB, FCU, BRR, LD, AD	N/A	Dynamic Peak: % of iEMGmax
Caty et al (2007)	Co-contraction	25m semi-tethered swim	Unilateral: Right Side Upper Limbs: FCU, ECU	Power(W)	Dynamic Peak: % of iEMGmax
Lauer et al (2013)	Co-contraction	200m FC	Unilateral: Right Side Upper Limbs: BB, TB	Elbow angular velocity(deg/s)	Dynamic Peak: % of iEMGmax
Matsuda et al (2016)	Co-contraction	Flutter Kick	Unilateral: Side - Not Mention Lower Limbs: RF; BF	Velocity(m/s), Kick time(s), Kick length(m/kick), Max. angular velocity(deg/s)	Dynamic Peak: Peak Value from 10 kick cycles
Yamakawa et al (2017)	Co-contraction**	Dolphin Kick	Unilateral: Right Side Trunk: RA, ES Lower Limbs: TA, GAS, RF, BF	Average SV(m/s), Froude Efficiency, KF(Hz), Kick Amplitude(m), Average & Max. Vertical Toe Velocities(m/s), % of downward & upward kick phases	Not mentioned
Martens et al (2015a)	Intra-variability of muscle activity	25m FC Swim	Bilateral Sides: Upper Limbs: DM Trunk: RA	N/A	MVIC & Dynamic Peak
Martens et al (2016)	Inter-variability of muscle activity	25m FC Swim	Bilateral Sides: Upper Limbs: DM Trunk: RA	N/A	MVIC
Ikuta et al (2012)	Muscle activation pattern**	200m FC	Unilateral: Right Side Upper Limbs: FCU, BB, PM, LD, TB, AD, PD Lower Limbs: TA, GAS, RF, BF	SV(m/s), SL(m) AAV of shoulder flexion	Not mention
Figueiredo et al (2013)	Muscle activation pattern	200m FC swim	Unilateral: Right Side Upper Limbs: FCR, BB, TB, PM, UT Lower Limbs: BF, RF	SV(m/s), SF(Hz), SL(m), KF(Hz), Hand angular velocity(rad/s) Elbow & shoulder angles(deg)	Dynamic Peak: % of iEMGmax
Pereira et al (2015)	Muscle activation pattern	Flip Turn	Side: Not Mention Lower Limbs: GASM, TA, BF, VL	Time of each phase of turn(s), Horizontal velocity of COM(m/s), Initial Rolling Distance(m)	MVIC
Kobayashi et al (2016)	Muscle activation pattern	15m dolphin kick	Unilateral: Side – Not mention Trunk Muscles: RA, ES Lower Limbs: RF, BF, TA, GAS	Average SV(m/s), KF(Hz), Kick amplitude(m), % of downward & upward phases	Dynamic Peak: Peak Value of 3 kick cycles
Stirn et al (2011)	Muscle Fatigue	100m FC	Unilateral: Right Side Upper Limbs: TB, PM & LD	SV(m/s), SL(m), SR(stroke/min)	Not mentioned
Lomax et al (2014)	Muscle Fatigue	20s arms only FC	Unilateral: Right Side Upper Limbs: PM, LD	SR(cycles/min)	Not mentioned
Figueiredo et al (2013)	Muscle Fatigue	200m FC	Unilateral: Side – Not mention Upper Limbs: FCR, BB, PM, UT, TB Lower Limbs: TA, RF, BF	SF(Hz), SL(m), SV(m/s)	Dynamic Peak: % of iEMGmax

Unit: cycle/min: cycle/minute; deg: degree; deg/s: degree/second; Hz: Hertz; m: meter; m/kick: meter/kick; m/s: meter/second; s: second; stroke/min: stroke/minute; rad/s: radian/second; W: Watt. Abbreviations - AAV: Arm angular velocity; AD: Anterior Deltoid; BB: Biceps Brachii; BF: Biceps Femoris; BRR: Brachioradialis; COM: Centre of Mass; DM: Deltoideus Medialis; ECU: Extensor Carpi Ulnaris; EMG: Electromyography; ES: Erector Spinae; FC: Front crawl/ Freestyle; FCR: Flexor Carpi Radialis; FCU: Flexor Carpi Ulnaris; GAS: Gastrocnemius; GASM: Gastrocnemius Medialis; iEMG_max: Maximum value of integrated electromyographic data; KF: Kick frequency; LD: Latissimus Dorsi; MVIC: Maximum Voluntary Isometric Contraction; N/A: Not applicable; PD: Posterior Deltoid; PM: Pectoralis Major; RA: Rectus Abdominis; RF: Rectus Femoris; SL: Stroke Length; SR: Stroke Rate; SV: Swimming Velocity; TA: Tibialis Anterior; TB: Triceps Brachii; UT: Upper Trapezius; VL: Vastus Lateralis.**: Secondary purpose: investigation of the relationships with the kinematics parameters with EMG data.