Adaptations of gait and muscle activation in chronic ACL deficiency

Abstract

The purpose was to investigate whether deviations in gait parameters or muscular activity patterns can be detected in the injured and healthy leg of chronic ACL-deficient subjects. Sixteen medium-level active chronic ACL-deficient patients classified as "copers" (injury duration: 12-240 months, age 17-52 years) and 15 healthy subjects (age 20-33 years) walked at self-selected speed along a 10-m runway with a level force-plate. Gait specific data, ground reaction forces, knee and ankle angles, and EMG were documented. Knee laxity was increased and the functional scores (Lysholm, KOOS) decreased in the ACL- deficient subjects, whereas the Tegner activity level score was normal. Gait speed, stride length and stance time did not differ between ACL-deficient subjects and controls. Ground reaction forces (magnitude and times), as well as knee and ankle angles at selected points during stance and swing phases were normal in the ACL-deficient subjects compared to controls. The total duration of m. tibialis anterior (TA) activity was longer in ACL-deficient subjects than in controls (ACL-deficient injured leg vs. controls, P < 0.05). In addition, the onset of lateral gastrocnemius (LG) muscle activity occurred earlier in ACL-deficient patients (P < 0.03), resulting in a TA-LG cocontraction in the ACL-deficient but not in the control group. In conclusion, chronic, medium-level active ACL-deficient patients showed abnormalities in muscular activity patterns during gait compared to control subjects, whereas there were no detectable changes in ground reaction forces and 3D kinematic data. As the aberrant muscular activity pattern may be of importance for an even gait, it is proposed that EMG recordings may give additional information in the evaluation and rehabilitation of gait when the ACL is absent.

Lower extremity muscle activation onset times during the transition from double-leg stance to single-leg stance in anterior cruciate ligament injured subjects

“…Nevertheless, the delayed muscle activation onset times of the knee muscles in the acute phase after ACL injury are in line with the findings of Wojtys and Huston (1994). Other studies measuring muscle activation onset times after ACL injury mainly included chronic ACLI subjects (>6 months after injury) and reported mixed results (Beard et al, 1993;Bryant et al, 2009;Kalund et al, 1990;Lindstrom et al, 2009;Sinkjaer & Arendt-Nielsen, 1991). A previous study using the same experimental task in subjects with chronic ankle instability also reported delayed muscle activation onset times not only around the injured joint, but the absolute values of the delays cannot be compared, as the speed of movement was not standardized and the Mx onset was defined differently in their study (Van Deun et al, 2007).…”

“…The majority of previous studies assessing muscle activation patterns after ACL injury mainly focused on muscles surrounding the injured knee joint (Aalbersberg et al, 2009;Beard et al, 1993;Boerboom et al, 2001;Branch et al, 1989;Bryant et al, 2009;Ciccotti et al, 1994;Gauffin & Tropp, 1992;Houck et al, 2007;Kalund et al, 1990;Klyne et al, 2012;Lindstrom et al, 2009;Sinkjaer & Arendt-Nielsen, 1991;Swanik et al, 1999Swanik et al, , 2004Wojtys & Huston, 1994). The current study is the first to evaluate muscle activation onset times of the knee, hip and ankle after ACL injury during a standardized functional task, the transition from DLS to SLS.…”

The effect of anterior cruciate ligament rupture on the timing and amplitude of gastrocnemius muscle activation: A study of alterations in EMG measures and their relationship to knee joint stability

“…Certainly, Kvist and Gillquist (2001) documented gastrocnemius and quadriceps co-contraction during various weight bearing tasks and concluded that such strategies could assist knee stability by virtue of joint compression. More recently, similar co-contraction strategies have also been observed in the lateral gastrocnemius and tibialis anterior muscles in ACLD individuals during level walking (Lindstrom et al, 2010).…”

“…In a similar task however, ACLD subjects elicited earlier activation of gastrocnemius to coincide with heel strike without concurrent increases in total muscle activity (Kuster et al, 1995). Comparable findings have recently been observed during level walking (Lindstrom et al, 2010). Finally, increased levels of medial gastrocnemius (MG) preparatory activity have been recorded in healthy subjects with ACL ligaments of above average laxity (>7 mm) prior to perturbation (Shultz et al, 2004).…”

“…Because isolated gastrocnemius contraction has been shown to strain the ACL in non-weight bearing (Fleming et al, 2001), these changes are considered by some to be a protective mechanism against excessive ATT (Papadonikolakis et al, 2003). However, many argue that gastrocnemius can aid knee stability by increasing joint stiffness (Chmielewski et al, 2002;Kvist and Gillquist, 2001) and restricting anterior tibial shear in weight bearing (Lindstrom et al, 2010;Sherbondy et al, 2003). In support of this notion, Reed-Jones and Vallis (2008) observed greater gastrocnemius muscle activity during downhill walking in ACLD individuals, which they attributed to an attempt to compensate for increased joint laxity and to enhance knee stability.…”