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

Table 4 Correlations between TSP points and SEMG _ratios in Single- and Double Leg Squat (SLS, DLS)

SLS
Substitution pattern according to TSP	SEMG_ratio for muscle	Time bin	r_s (95% CI) p-value
“lateral displacement of the hip-pelvis region on the supporting side”	biceps femoris	1	−0.71 (−0.89 to −0.33) 0.002
“lateral displacement of the hip-pelvis region on the supporting side”	quadriceps	6/7	−0.54 (−0.82 to −0.06) 0.03
“knee medial to the supporting foot”	gluteus medius	6/7	−0.73 (−0.90 to −0.36) 0.001
“displacement of the trunk”	gluteus medius	6/7	0.62 (0.18 to 0.85) 0.01
“pronation of the foot”	tibialis anterior	11	−0.60 (−0.84 to −0.14) 0.015
“displacement of the trunk”	tibialis anterior	11	−0.50 (−0.80 to −0.01) 0.047
DLS
“displacement of body weight to either side”	tibialis anterior	11	−0.51 (−0.80 to −0.02) 0.043

Correlations between the points scored for the substitution patterns in injured side and SEMG_ratios for the muscles recorded, in the test-movements Single Leg Squat (SLS) and Double Leg Squat (DLS), for the 16 participants with ACL rupture. Spearman’s correlation coefficients, the 95% confidence interval and p-value are presented for time bins 1, 6/7 and 11 with statistically significant correlations.
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.
r_s = Spearman’s correlation coefficient.
95% CI = 95% confidence interval.

ISSN: 1471-2474