Unilateral Quadriceps Strengthening With Disinhibitory Cryotherapy and Quadriceps Symmetry After Anterior Cruciate Ligament Reconstruction

Abstract

Context: The effect of unilateral cryotherapy-facilitated rehabilitation exercise on involved-limb quadriceps function and limb symmetry in individuals with quadriceps dysfunction after anterior cruciate ligament reconstruction (ACLR) remains unclear.Objective: To measure the effect of a 2-week unilateral cryotherapy-facilitated quadriceps-strengthening program on knee-extension strength and quadriceps central activation ratio (CAR) in participants with ACLR.Design: Controlled laboratory study. Setting: Laboratory. Patients or Other Participants: A total of 10 volunteers with unilateral ACLR (1 man, 9 women; age ¼ 21.0 6 2.8 years, height ¼ 164.6 6 5.0 cm, mass ¼ 64.0 6 6.1 kg, body mass index ¼ 23.7 6 2.7 kg/m 2 ) and 10 healthy volunteers serving as control participants (1 man, 9 women; age ¼ 20.8 6 2.5 years, height ¼ 169.1 6 6.2 cm, mass ¼ 61.1 6 6.4 kg, body mass index ¼ 21.4 6 2.3 kg/m 2 ) participated. Intervention(s): Participants with ACLR completed a 2-week unilateral cryotherapy-facilitated quadriceps-strengthening intervention.Main Outcome Measure(s): Bilateral normalized kneeextension maximal voluntary isometric contraction (MVIC) torque (Nm/kg) and quadriceps CAR (%) were assessed preintervention and postintervention. Limb symmetry index (LSI) was calculated at preintervention and postintervention testing. Preintervention between-groups differences in unilateral quadriceps function and LSI were evaluated using independentsamples t tests. Preintervention-to-postintervention differences in quadriceps function were evaluated using paired-samples t tests. Conclusions: Two weeks of cryotherapy-facilitated exercise may improve involved-limb quadriceps function while preserving between-limbs symmetry in patients with a history of ACLR.Key Words: disinhibitory modalities, quadriceps strength, quadriceps central activation ratio, limb symmetry index, crosseducation Key PointsA 2-week cryotherapy-facilitated strengthening program may improve involved-limb quadriceps function and preserve between-limbs symmetry in patients with a history of anterior cruciate ligament reconstruction. Clinicians should consider using this approach when treating patients with persistent quadriceps weakness during recovery from anterior cruciate ligament reconstruction.

Neuromotor Treatment of Arthrogenic Muscle Inhibition After Knee Injury or Surgery

“…Specifically, hamstring fatigue exercises may improve quadriceps activation but do not overcome muscle inhibition. 16 Recently, studies have demonstrated both neural excitability differences and cortical reorganization occurrence in injured persons, in particular patients with ACL injuries when compared with uninjured subjects. 20,27 These studies highlighted both the requirement of special training programs other than regular physical activities and the need to identify interventions aimed to impact the neurological aspect of quadriceps weakness.…”

“…Among them, cryotherapy, transcutaneous electrical nerve stimulation, electromyographic (EMG) biofeedback, transcranial magnetic stimulation, and neuromuscular electrical stimulation may be beneficial to counteract the negative effects of AMI during a short rehabilitation session (30-90 min). 3,16,21,31,32,34 Despite improvements in quadriceps function (knee extension strength, quadriceps activation, and EMG activity), persistent deficits have been found, hence possible failures in current treatment strategies. 3,11,22,36,38 Indeed, recent reviews by Sonnery-Cottet et al 37 and Tayfur et al 38 concluded that there was low-to-moderate quality evidence for the efficacy of therapeutic interventions and a lack of activation deficit resolution in the long term.…”

Arthrogenic Muscle Inhibition Following Anterior Cruciate Ligament Injury

“…139 Another small laboratory study (N = 10) found that 2 weeks of therapeutic exercise combined with cryotherapy resulted in improved voluntary quadriceps activation and muscle strength in ACLR individuals who were an average of 28 ( 17) months post-ACLR. 140 While both TENS and cryotherapy demonstrate promise for directly improving rehabilitation outcomes following ACLR, larger high quality randomized controlled trials are needed to determine the overall effectiveness of these interventions.…”