Individuals following anterior cruciate ligament reconstruction practice underloading strategies during daily activity

Abstract

Underloading the surgical limb has been described in biomechanical studies across recovery time points following anterior cruciate ligament reconstruction (ACLr). This study aimed to examine the extent to which laboratory findings translate to daily activities.Limb loading was quantified during a sit-to-stand task in laboratory testing and throughout 2 days of daily activity in 15 individuals 114.8 (17.2) days post-ACLr and 15 controls. Vertical force impulse calculated from force platform (laboratory) and pressure insoles (daily) was used to quantify limb loading. Between-limb symmetry was calculated for limb loading and knee strength measures, 2 × 2 GLM repeated measures determined a significant group-by-limb interaction on daily limb loading. Surgical limb daily loading was lower compared to nonsurgical (p < .001; effect sizes [ES] = 0.63), and control matched limbs (surgical: p = .037, ES = 0.80 and nonsurgical: p = .02, ES = 0.89). No group differences were found in total daily loading (summed loading between limbs; p = .18; ES = 0.50) and time performing weight-bearing activities (p = .32; ES = 0.36).Pearson's correlation determined that between-limb symmetry in daily loading was related to sit-to-stand loading (r = .62; p = .01) and knee extensor strength symmetry (r = .6; p = .02) in the ACLr group. These data support the presence of underloading behaviors in individuals 10-14 weeks following ACLr that are consistent with previous biomechanical studies and current biomechanical data. Knee extensor weakness was related to greater underloading. Asymmetrical loading quantified in the laboratory is practiced throughout the day in individuals post-ACLr. Practice afforded by daily activities represents powerful contributors to learning of a pattern that contrasts the goal of rehabilitation exercises.

Towards Out-of-Lab Anterior Cruciate Ligament Injury Prevention and Rehabilitation Assessment: A Review of Portable Sensing Approaches

“…Twenty-one studies (43%) recruited patients following ACLR. The time from ACLR to experimental testing were within 3 months [33, 34, 40, 60, 61, 65], 3-12 months [28, 29, 32, 34, 39, 40, 46, 48, 62, 64, 65, 67-69, 72], or more than 12 months [35, 38, 48, 72] for the recruited patients. Eight studies (16%) recruited athletes at high risk of ACL injury, including basketball players [73, 74], soccer players [42, 59], and gymnasts [53].…”

“…Eight studies (16%) recruited athletes at high risk of ACL injury, including basketball players [73, 74], soccer players [42, 59], and gymnasts [53]. Eight studies (16%) explicitly reported that their experiments were performed out of lab, including clinics [34, 46, 64], hospitals [33], soccer fields [42], and unconstrained daily life [35, 62, 65].…”

“…24% of the included studies are in stage II, preliminary clinical validation, as they demonstrated their clinical utility. These studies successfully used portable sensors to detect deficits in patients following ACLR [62, 64, 65, 70, 72], identify subjects with high-risk movement patterns [37, 42, 47, 52, 73], and enable injury prevention training that led to significant reductions in ACL injury risk factors [44, 53, 56]. However, before the deployment of these studies, further clinical validation is needed to validate their test-retest reliability as well as effectiveness in accelerating the post-ACLR recovery, or predicting and reducing real-world injury incidence rate.…”

“…A few studies directly used raw sensor measurements for assessment [30,31,33,34,39,40,43,48,[61][62][63][64][70][71][72], for example, extracting peak acceleration and angular velocity from the thigh or shank IMU data for assessment [30,31,39,40,43,48,64]. Characteristics of the IMU data (e.g., local peaks) can also be used to segment gait cycles and derive step time asymmetry [33,34].…”

“…Sensing approaches are IMU [26,[29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48], depth camera [27,[49][50][51][52][53][54][55], RGB camera [56][57][58][59], EMG [60,61], pressure insole [62], soft fabric sensor [63], and multiple sensors [28,[64][65][66][67][68][69][70][71][72][73][74].…”