Altered movement patterns and muscular activity during single and double leg squats in individuals with anterior cruciate ligament injury

Table 3 SEMG _ratios for the Single Leg Squat (SLS) and the Double Leg Squat (DLS)

SLS
Muscle	Time bin 1	p	Time bin 6/7	p	Time bin 11	p
Muscle	Median (Q₁, Q₃)	p	Median (Q₁, Q₃)	p	Median (Q₁, Q₃)	p
Quadriceps vastus lateralis	0.78 (0.54, 1.18)	ns (0.12)	0.69 (0.62, 0.97)	0.05	0.73 (0.39, 1.05)	0.05
Peroneus longus	0.55 (0.33, 0.88)	0.03	0.72 (0.44, 1.36)	ns (0.16)	0.80 (0.49, 1.25)	ns (0.16)
DLS
Muscle	Time bin 1	p	Time bin 6/7	p	Time bin 11	p
Muscle	Median (Q₁, Q₃)	p	Median (Q₁, Q₃)	p	Median (Q₁, Q₃)	p
Biceps femoris	1.46 (1.00, 3.00)	0.04	0.66 (0.48, 0.80)	0.02	1.78 (1.02, 3.96)	ns (0.11)
Quadriceps vastus lateralis	0.64 (0.50, 1.00)	0.04	0.56 (0.38, 0.71)	0.003	0.66 (0.44, 0.99)	0.01
Tibialis Anterior	0.61 (0.17, 0.92)	0.02	0.82 (0.76, 0.99)	ns (0.15)	0.46 (0.13, 1.00)	0.02
Peroneus longus	0.53 (0.38, 0.98)	0.02	0.70 (0.35, 1.45)	ns (0.13)	0.61 (0.28, 1.19)	0.04

Median SEMG_ratios, quartiles and p-value for the Single Leg Squat (SLS), and the Double Leg Squat (DLS), for the muscles with statistically significant differences between sides in one or more of the time bins 1, 6/7 and 11, for the 16 participants with ACL rupture.
SEMG_ratio was calculated as the ratio of the average amplitude between injured and non-injured sides for each of the time bins 1, 6/7 and 11, so that an equal activation in injured and non-injured sides would correspond to 1.0. The calculations were made for all six muscles recorded.
SLS and DLS are included in the Test for Substitution Patterns where altered movements (substitution patterns) were scored as observable, predefined deviations of postural orientation; for details see Subjects and methods section.
Time bin = a time epoch. Time bin 1 corresponds to the instance prior to the beginning of the movement, time bin 6/7 to the transition from flexion to extension and time bin 11 to the end of the movement.
Q₁, Q₃ = quartiles 1 and 3.
p = p-value.
ns = non-significant.

ISSN: 1471-2474