Comparison of Lower Limb Mass, Thigh Circumference, and Balance Ability after Anterior Cruciate Ligament Reconstruction and in Control Participants.

Injury of the anterior cruciate ligament (ACL) in the knee is common, with up to 250,000 cases annually in the United States. Such injuries can lead to muscle atrophy, impaired balance, and limited movement. This study aimed to compare the lower limbs of individuals with ACL reconstruction to a Control group. We hypothesized that ACL participants would exhibit greater asymmetry between lower limbs as compared to Controls. Data were collected from 12 ACL participants and 30 Control participants. Measurements included lower limb muscle mass assessed using bioelectrical impedance, thigh circumference at 10 cm and 15 cm superior to the patella, and postural sway during single-leg stance. The results showed no significant difference in mass between the surgical and non-surgical lower limbs of ACL participants. Additionally, no significant differences were found in thigh circumference, or postural sway for ACL participants between the two limbs. In contrast, the Control group demonstrated significantly greater muscle mass ( = 0.005) in the dominant lower limbs compared to the non-dominant limbs. Thigh circumference at the 10 cm mark was also significantly greater on the dominant lower limbs than non-dominant lower limbs ( = 0.040). Our hypotheses were not supported, as asymmetry in mass and thigh circumference was demonstrated in Control but not ACL participants. No differences in postural sway were found between lower limbs in either ACL or Control participants. Loss of the ability to rely on the strength of a dominant lower limb may lead to functional deficits when participants undergo dominant limb ACL reconstruction.