Fig 1.
The 2009 PRISMA flowchart for the systematic review.
Table 1.
Summary of the characteristics of the systematic review studies that address passive knee flexion.
Table 2.
Summary of the characteristics of the systematic review studies that address passive flexion with 100 or 134 N posterior tibial load.
Table 3.
Summary of the characteristics of the reviewed studies that address forward lunge or body-weight squat.
Table 4.
Summary of the characteristics of the reviewed studies that address walking, stair ascent or stair descent.
Fig 2.
Binned scatter plot and weighted polynomial regression lines of all reported strain data for the AL, PM and mid-PCL bundles during passive knee flexion (R2 of 0.68, 0.04 and 0.46 respectively).
Each circle shows the mean of the data extracted from the individual studies, where the size of the circle represents the number of knees tested and the numerical labels detail the reference numbers from which data were extracted. Data points with strains of less than -25% or greater than +45% are not shown (resolution of bins: ±2%).
Fig 3.
Strain of the virtual mid-PCL bundle during passive knee flexion, separated according to the assessment categories used.
Articles in this graph included all data available for the mid-PCL: in vivo studies [31, 32], in vitro studies [19, 32, 51, 61, 82, 90], and modelling studies [35, 84, 92]. Experimental data were weighted based on the number of knees tested. Error bars show the Standard Error of Mean.
Fig 4.
Strain of the real and virtual bundles of the PCL during passive knee flexion.
Data were weighted based on the number of knees tested. Articles included in this graph: Studies on real bundles [26, 49] and studies on virtual bundles [19, 22, 24, 25, 27, 29, 51, 60, 61, 73, 82].
Fig 5.
Average force patterns of the PCL during knee flexion with and without Posterior Tibial Load (PTL).
Included articles in this graph: in vitro force in passive flexion [12, 13, 20, 62, 63, 86–89, 91], in situ force in passive flexion [9], modelling force in passive flexion [36, 75, 84], in vitro force with 100 N PTL [12, 13, 20, 86–88, 96, 97], in situ force with 100 N PTL [17] and in situ force with 134 N PTL [8, 15, 16, 18, 93–95, 98, 105].
Fig 6.
Average experimental strain patterns of the virtual PCL bundles during passive and active knee flexion.
Included articles in this graph: Studies on passive flexion [19, 22, 24, 25, 27, 29, 51, 60, 61, 73, 82] and studies on forward lunge [14, 30, 33, 57].