Elsevier

Gait & Posture

Volume 36, Issue 3, July 2012, Pages 609-613
Gait & Posture

Principal component analysis of knee kinematics and kinetics after anterior cruciate ligament reconstruction

https://doi.org/10.1016/j.gaitpost.2012.06.003Get rights and content

Abstract

This study compared the gait of 10 subjects with unilateral anterior cruciate ligament (ACL) reconstruction to a group of 12 height- and weight-matched control subjects. The analysis was based on knee flexion, adduction, and internal rotation angles and moments. The objective was to use principal component analysis (PCA) to identify knees of the ACL reconstructed subjects that fell outside normal ranges as determined by control subjects. Gait data were collected on all subjects in a motion analysis laboratory. Principal component (PC) models were developed for each gait measure based on the control subjects’ data and used to assess gait waveforms of ACL reconstructed subjects. PCA allows analysis of entire gait waveforms for comparisons. In a sample of 10 ACL reconstructed subjects (7 years after surgery, on average), six of the ACL reconstructed knees had not returned to normal following surgery and eight of the contralateral knees functioned differently from controls. A majority of the differences were noted to occur in the abduction–adduction knee moment with corresponding infrequency in the differences seen in abduction–adduction rotation. PCA enabled us to identify subjects with abnormal gait waveforms as outliers relative to the normal control group.

Highlights

► We identify knees of ACL reconstructed subjects that fall outside normal ranges. ► Principal component models were developed for dynamic gait measures. ► These models were used to assess gait waveforms of ACL reconstructed subjects. ► The majority of differences occurred in the abduction–adduction knee moment.

Section snippets

Background

More than 250,000 people tear their anterior cruciate ligament (ACL) in the United States each year. ACL injury often leads to kinematic changes in the knee, resulting in instability, and osteoarthritic changes over time [1], [2]. In vivo studies of squatting and walking have shown increased anterior–posterior translation and altered internal–external (IE) rotation of the tibia with respect to the femur in ACL deficient knees using a variety of methods, including MRI [3], fluoroscopy [2], and

Subjects

Twenty-two subjects participated in this investigation. Ten (four male and six female) ACL reconstructed individuals were compared with 12 (six male and six female) healthy uninjured height- and weight-matched control subjects. The mean body weight and height of the ACL reconstructed subjects were 77.6 kg (SD 19.5 kg) and 1.73 m (SD 0.10 m). The ACL reconstructed subjects had sustained an isolated unilateral ACL tear during sports activity and were surgically reconstructed with bone-patellar

Results

PC models were developed for each of the knee angles and moments (Table 1). The number of PCs retained in each model (k) was chosen through an 85% trace criterion [8], [9]. Table 2 provides a gait assessment of the ACL subjects using the PC models. A significant difference from normal implies that either or both the T2 and the Q values are above the upper limits defined by control subjects. Of the 10 ACL subjects, nine showed deviation from normal gait in either or both knees in at least one of

Discussion

We hypothesized that alterations in 3-dimensional knee rotations and moments during the stance phase of gait could be detected as outliers following ACL reconstruction using principal component analysis. The work presented here shows that abnormalities in gait waveforms can be detected in subjects who have undergone ACL reconstruction surgery. Of the 20 knees analyzed, 45% displayed abnormal adduction moment waveforms during the stance phase of gait. These included both ACL reconstructed and

Conclusions

Principal component analysis enabled us to identify gait waveforms which deviate from normal as assessed using a control population. We determined in a sample of 10 ACL reconstructed subjects that six of the ACL reconstructed knees had not returned to normal following surgery and that eight of the contralateral knees functioned differently, presumably as a result of alterations in the reconstructed knee. We believe that each subject has a unique response to their injury and reconstructive

Conflict of interest statement

The authors declare that they have no competing interests.

References (26)

Cited by (23)

  • Gait analysis of young male patients diagnosed with primary bladder neck obstruction

    2017, Journal of Electromyography and Kinesiology
    Citation Excerpt :

    In particular, we relied on a principal component analysis (PCA) approach: PCA is a multivariate statistical technique that allows to find the main features of a large-dimensional dataset. In the context of gait analysis, PCA allows to extract fundamental information from entire gait waveforms, as opposed to arbitrarily-selected parameters and was already adopted to investigate different features of gait in normal and pathological populations (Deluzio et al., 1997; Astephen and Deluzio, 2005; Deluzio and Astephen, 2007; Sanford et al., 2012). In sum, the aim of this study was to identify and unveil kinematic imbalances which are usually ignored and uninvestigated in PBNO patients, and which could eventually be involved in the etiopathogenesis of the disease.

  • Contralateral limb deficit seven months after ACL-reconstruction: An analysis of single-leg hop tests

    2015, Knee
    Citation Excerpt :

    However, some authors have highlighted deficits on the reference leg, the NIL, after ACL injury and/or ACL-R [14–21]. Proprioception and force deficits [21], muscular activation reduction [16], postural control modification [17,18], and gait [15] and jump landing deficits [22] have been demonstrated in the NIL after ACL injury and/or ACL-R. Certain authors have suggested a central adaptation after ACL injury and/or ACL-R that could reduce the NIL's capacity to help preserve symmetry between the IL and NIL [16,18]. Another factor could be related to detraining effects, due to the long period of physical inactivity after ACL injury.

  • Frontal plane knee mechanics and medial cartilage MR relaxation times in individuals with ACL reconstruction: A pilot study

    2014, Knee
    Citation Excerpt :

    Multiple studies have shown that individuals with ACL-reconstruction (ACL-R) continue to demonstrate abnormal walking mechanics of the reconstructed knee when compared to the contralateral knee and compared to control subjects [4–6]. Higher KAM in the ACL-R knees compared to control knees has been reported [6,35]. However, other studies have reported no difference in KAM [7] or even lower KAM in the ACL-R knees [5].

  • A Systematic Method for Outlier Detection in Human Gait Data

    2022, IEEE International Conference on Rehabilitation Robotics
View all citing articles on Scopus

Supported in part by a grant from FedEx Institute of Technology.

1

These authors contributed equally to this work.

View full text