Feasibility of Muscle Synergy Outcomes in Clinics, Robotics, and Sports: A Systematic Review

Table 4

Selected locomotion and balance studies using muscle synergies.

Reference	Pathology	Aim	Subjects	Tasks	Muscles (segments)	Outcomes
[17] Clark et al. 2010	Stroke	Evaluate change in motor control	55 patients; 20 healthy subjects	Overground walking and treadmill	16 (lower limbs)	(i) Reduced synergies in patients; (ii) Number of synergies related to walking performance
[18] Ferrante et al. 2016	Stroke	Design a multichannel functional electrical stimulation controller	2 patients; 13 healthy subjects	Overground walking and treadmill	7 (lower limb)	(i) Four synergies in healthy subjects; (ii) Three synergies in patients; (iii) Four synergies after FES
[19] Kautz et al. 2017	Stroke	Evaluate change in motor control	56 patients; 17 healthy subjects	Overground walking and treadmill	16 (lower limbs)	(i) Similar muscle synergies in the two walking conditions
[20] Gizzi et al. 2011	Stroke	Evaluate change in motor control	10 patients; 10 healthy subjects	6 m long walking	32 (full-body)	(i) Different muscle synergy vectors; (ii) Similar activation profiles and number of synergies
[22] Hashiguchi et al. 2016	Stroke	Evaluate change in muscle synergies due to rehabilitation	13 patients	Overground walking	8 (lower limb)	(i) Same number of muscle synergies; (ii) Merging synergies as an index for motor coordination
[23] Coscia et al. 2015	Stroke	Assess the relationship between gait asymmetry and muscle synergies	12 patients; 10 healthy subjects	Walking on a treadmill	24 (lower limbs)	(i) Similar muscle synergies in less affected limb; (ii) Altered muscle synergy organization in the affected limb
[24] Barroso et al. 2017	Stroke	Assess the walking performance	9 patients	Overground walking	22 (trunk and lower limb)	(i) Fewer synergies in the paretic side; (ii) Muscle synergies useful for walking performance assessment
[25] Steele et al. 2015	Cerebral palsy	Examine motor modification	549 patients; 84 healthy children	Overground walking	5 (lower limb)	(i) Reduced synergies in patients; (ii) Number of synergies as index for CP assessment
[27] Shuman et al. 2017	Cerebral palsy	Evaluate the repeatability of muscle synergies across days	5 patients; 6 healthy children	Overground walking	16 (lower limbs)	(i) Reduced synergies in patients; (ii) Muscle synergies repeatable between days in both groups
[28] Fox et al. 2013	Spinal cord injury	Evaluate change in motor control	5 patients; 5 healthy children	Locomotion tasks	12 (lower limb)	(i) Reduced synergies in patients; (ii) Similar modular organization for all tested tasks
[29] Hayes et al. 2014	Spinal cord injury	Quantify neuromuscular deficits in muscle coordination	8 patients; 8 healthy subjects	Overground walking	14 (lower limb)	(i) Different synergy organization; (ii) Similar synergy during walking with metronome
[30] Allen et al. 2017	Parkinson’s disease	Assess changes in control of gait and balance after dance-based rehabilitation	9 patients	Dance (tango)	13 (lower back and limb)	(i) No modifications in muscle synergies; (ii) Decrease in muscle synergy variability
[31] Rodriguez et al. 2013	Parkinson’s disease	Evaluate change in motor control	15 patients; 14 healthy older	Walking on a treadmill	16 (lower limbs)	(i) Reduced synergies in patients; (ii) Similar muscle synergies; (iii) Different activation profiles
[32] Lencioni 2016	Multiple sclerosis	Evaluate change in motor control	17 patients; 12 healthy subjects	Overground walking	8 (lower limb)	(i) Similar muscle synergy organization; (ii) Different activation profiles
[33] Serrancolì et al. 2016	Anterior cruciate ligament	Evaluate change in motor control	18 patients; 10 healthy subjects	Overground walking	16 (lower limbs)	(i) Higher cocontraction in patients; (ii) Different activation profiles
[34] Monaco et al. 2010	Aging	Evaluate change in motor control	7 younger subjects; 7 older subjects	Overground walking	12 (lower limb)	(i) Similar muscle synergy organization
[51] Tang et al. 2015	Cerebral palsy	Assess lower extremity dysfunction	12 patients; 8 healthy children; 10 healthy adults	Overground walking	16 (lower limbs)	(i) Greater variability in muscle synergy organization in patients; (ii) Relationship between muscle synergies and motor dysfunctions