The effects of cryotherapy on quadriceps electromyographic activity and isometric strength in patient in the early phases following knee surgery

Quadriceps Activation After Anterior Cruciate Ligament Reconstruction: The Early Bird Gets the Worm!

Arthrogenic Muscle Inhibition (AMI) is a phenomenon observed in individuals with joint injury or pathology, characterized by a reflexive inhibition of surrounding musculature, altered neuromuscular control, and compromised functional performance. After anterior cruciate ligament reconstruction (ACLR) one of the most obvious consequences of AMI is the lack of quadriceps activation and strength. Understanding the underlying mechanisms of AMI is crucial for developing effective therapeutic interventions. The surgical procedure needed to reconstruct the ACL has biochemical et physiological consequences such as inflammation, pain, and altered proprioception. These alterations contribute to the development of AMI. Therapeutic interventions aimed at addressing AMI encompass a multidimensional approach targeting pain reduction, inflammation management, proprioceptive training, and quadriceps activation. Early management focusing on pain modulation through modalities like ice, compression, and pharmacological agents help mitigate the inflammatory response and alleviate pain, thereby reducing the reflexive inhibition of quadriceps. Quadriceps activation techniques such as neuromuscular electrical stimulation (NMES) and biofeedback training aid in overcoming muscle inhibition and restoring muscle strength. NMES elicits muscle contractions through electrical stimulation, bypassing the inhibitory mechanisms associated with AMI, thus facilitating muscle activation and strength gains. Comprehensive rehabilitation programs tailored to individual needs and stage of recovery are essential for optimizing outcomes in AMI. The objective of this clinical viewpoint is to delineate the significance of adopting a multimodal approach for the effective management of AMI, emphasizing the integration of pain modulation, proprioceptive training, muscle activation techniques, and manual therapy interventions. Highlighting the critical role of early intervention and targeted rehabilitation programs, this article aims to underscore their importance in restoring optimal function and mitigating long-term complications associated with AMI.

Neuromotor Treatment of Arthrogenic Muscle Inhibition After Knee Injury or Surgery

BACKGROUND

Persistent weakness of the quadriceps muscles and extension deficit after knee injuries are due to specific alterations in neural excitability - a process known as arthrogenic muscle inhibition (AMI). The effects of a novel neuromotor reprogramming (NR) treatment based on the use of proprioceptive sensations associated with motor imagery and low frequency sounds have not been studied in AMI after knee injuries.

HYPOTHESIS

This study aimed to assess quadriceps electromyographic (EMG) activity and the effects on extension deficits in persons with AMI who completed 1 session of NR treatment. We hypothesized that the NR session would activate the quadriceps and improve extension deficits.

STUDY DESIGN

Case series.

LEVEL OF EVIDENCE

Level 4.

METHODS

Between May 1, 2021 and February 28, 2022, patients who underwent knee ligament surgery or sustained a knee sprain with a deficit of >30% of the vastus medialis oblique (VMO) on EMG testing in comparison with the contralateral limb after their initial rehabilitation were included in the study. The maximal voluntary isometric contraction of the VMO measured on EMG, the knee extension deficit (distance between the heel and the table during contraction), and the simple knee value (SKV) were assessed before and immediately after completion of 1 session of NR treatment.

RESULTS

A total of 30 patients with a mean age of 34.6 ± 10.1 years (range, 14-50 years) were included in the study. After the NR session, VMO activation increased significantly, with a mean increase of 45% (P < 0.01). Similarly, the knee extension deficit significantly improved from 4.03 ± 0.69 cm before the treatment to 1.93 ± 0.68 after the treatment (P < 0.01). The SKV was 50 ± 5.43% before the treatment, and this increased to 67.5 ± 4.09% after the treatment (P < 0.01).

CONCLUSION

Our study indicates that this innovative NR method can improve VMO activation and extension deficits in patients with AMI. Therefore, this method could be considered a safe and reliable treatment modality in patients with AMI after knee injury or surgery.

CLINICAL RELEVANCE

This multidisciplinary treatment modality for AMI can enhance outcomes through the restoration of quadriceps neuromuscular function and subsequent reduction of extension deficits after knee trauma.

The Influence of Cold Therapy on the Physical Working Capacity at the Electromyographic Threshold for Consecutive Exercise Sessions

BACKGROUND

The purpose of this study was to determine whether cold therapy after the first exercise test influences the physical working capacity at the fatigue threshold (PWCFT) during the second exercise test. We hypothesized that cold therapy would delay the onset of PWCFT for the second exercise test relative to the control visit (i.e., no cold therapy).

METHODS

Eight healthy college-aged men volunteered for the present study. For each of the two visits, subjects performed incremental, single-leg, knee-extensor ergometer, followed by either resting for 30 min (control visit) or having a cold pack applied for 15 min and then resting for 15 min (experimental visit). Then, the same exercise test was performed. The order of visits (control vs. experimental) was randomized for each subject. The exercise indices and PWCFT were determined for each of the two visits and statistically analyzed using two-way repeated measures analysis of variance.

RESULTS

The results indicate no significant (p > 0.05) mean differences for maximal power output, heart rate at end-exercise, and PWCFT between the control and cold therapy visits. Moreover, there were no significant (p > 0.05) mean differences between the first and second exercise workbout within each visit.

CONCLUSIONS

The findings of this study suggest that cold therapy did not influence neuromuscular fatigue.

The past and future of peri-operative interventions to reduce arthrogenic quadriceps muscle inhibition after total knee arthroplasty: A narrative review

Total knee arthroplasty (TKA) improves patient-reported function by alleviating joint pain, however the surgical trauma exacerbates already impaired muscle function, which leads to further muscle weakness and disability after surgery. This early postoperative strength loss indicates a massive neural inhibition and is primarily driven by a deficit in quadriceps muscle activation, a process known as arthrogenic muscle inhibition (AMI). To enhance acute recovery of quadriceps muscle function and long-term rehabilitation of individuals after TKA, AMI must be significantly reduced in the early post-operative period. The aim of this narrative review is to review and discuss previous efforts to mitigate AMI after TKA and to suggest new approaches and interventions for future efficacy evaluation. Several strategies have been explored to reduce the degree of post-operative quadriceps AMI and improve strength recovery after TKA by targeting post-operative swelling and inflammation or changing neural discharge. A challenge of this work is the ability to directly measure AMI and relevant contributing factors. For this review we focused on interventions that aimed to reduce post-operative swelling or improve knee extension strength or quadriceps muscle activation measured by twitch interpolation. For individuals undergoing TKA, the use of anti-inflammatory medications, tranexamic acid, cryotherapy, intra-articular drains, torniquets, and minimally invasive surgical techniques for TKA have limited benefit in attenuating quadriceps AMI early after surgery. However, interventions such as inelastic compression garments, voluntary muscle contractions, and neuro-muscular electrical stimulation show promise in mitigating or circumventing AMI and should continue to be refined and explored.

Bilateral Knee Joint Cooling on Anaerobic Capacity and Wheel Cadence during Sprint Cycling Intervals

We compared the effect of bilateral knee joint cooling with or without a pre-cooling warm-up on sprint cycling performance to a non-cooling control condition. Seventeen healthy young males (25 ± 2 years, 174 ± 6 cm, 70 ± 9 kg) performed three conditions in a counterbalanced order (condition 1: warming + cooling + cycling; condition 2: cooling + cycling; condition 3: cycling). For warming, a single set of cycling intervals (a 10 s sprint with maximal effort followed by a 180 s active recovery; resistive load 4% and 1% body mass for sprint and recovery, respectively) was performed. For cycling, five sets of cycling intervals were performed. For cooling, 20 min of bilateral focal knee joint cooling was applied. Peak and average values of anaerobic capacity and wheel cadence during each set across conditions were statistically compared. There was no condition effect over set (condition × set) in anaerobic capacity (F8,224 < 1.49, p > 0.16) and wheel cadence (F8,224 < 1.48, p > 0.17). Regardless of set (condition effect: F2,224 > 8.64, p < 0.0002), conditions 1 and 2 produced higher values of anaerobic capacity (p ≤ 0.05). Similarly (condition effect: F2,224 > 4.62, p < 0.02), condition 1 showed higher wheel cadence (p < 0.02) than condition 3. A bilateral joint cooling for 20 min with or without pre-cooling warm-up may improve overall sprint cycling capacity during five sets of cycling intervals when compared to the non-cooling condition.

Direct Effect of Local Cryotherapy on Muscle Stimulation, Pain and Strength in Male Office Workers with Lateral Epicondylitis, Non-Randomized Clinical Trial Study

Background: Local cryotherapy (LC) is one of the physiotherapeutic methods used in the conservative treatment of lateral epicondylitis (LE). The aim of the study was to verify the direct effect of a single LC procedure on the clinical symptoms of lateral epicondylitis enthesopathy (pain, pain free grip, PFG) and its effect on the bioelectrical properties of the wrist extensor muscles at rest, on maximal contraction and isometric contraction during fatigue. Methods: The study group was 28 men (35.4 ± 6.13 years) with confirmed unilateral epicondylitis. The performed procedures included the assessment of pain (visual analogue scale, VAS), PFG and ARMS (root-mean-square amplitude) and mean frequencies (MNF) of the sEMG signal before (T0) and after (T1) LC on the side with enthesopathy (ECRE) and without enthesopathy (ECRN/E). Results: There was an increase in the ARMS values of the signals recorded during rest and MVC from the ECR muscles both with and without enthesopathy (p = 0.0001, p = 0.006), an increased PFG after LC only on the side with LE (p < 0.0001) and decreased pain (p < 0.0001). During isometric fatigue contraction, a higher ARMS on both the ECRE side (p < 0.0001) and the ECRN/E side (p < 0.0001) was observed after LC treatment, and a lower MNF was observed on both the ECRN/E side (p < 0.0001) and the ECRE side (p < 0.0001) after LC. Conclusions: LC reduces the pain and increases PFG and muscle excitation expressed by ARMS and seems to delay muscle fatigue.

Arthrogenic Muscle Inhibition Following Anterior Cruciate Ligament Injury

Arthrogenic muscle inhibition (AMI) is a common impairment in individuals who sustain an anterior cruciate ligament (ACL) injury. The AMI causes decreased muscle activation, which impairs muscle strength, leading to aberrant movement biomechanics. The AMI is often resistant to traditional rehabilitation techniques, which leads to persistent neuromuscular deficits following ACL reconstruction. To better treat AMI following ACL injury and ACL reconstruction, it is important to understand the specific neural pathways involved in AMI pathogenesis, as well as the changes in muscle function that may impact movement biomechanics and long-term structural alterations to joint tissue. Overall, AMI is a critical factor that limits optimal rehabilitation outcomes following ACL injury and ACL reconstruction. This review discusses the current understanding of the: (1) neural pathways involved in the AMI pathogenesis following ACL injury; (2) consequence of AMI on muscle function, joint biomechanics, and patient function; and (3) development of posttraumatic osteoarthritis. Finally, the authors review the evidence for interventions specifically used to target AMI following ACL injury.

Effects of Focal Knee Joint Cooling on Static and Dynamic Strength of the Quadriceps: Innovative Approach to Muscle Conditioning

Recent evidence suggests an innovative approach to muscle conditioning: focal knee joint cooling (FKJC) appears to improve quadriceps function, including static (isometric) strength. However, there is limited evidence on the effects of FKJC on dynamic (concentric and eccentric) strength. Thus, the purpose of the study was to examine dynamic quadriceps strength following FKJC as well as static strength. Twenty-one college-aged participants volunteered. They randomly underwent 20 min of FKJC and control condition at least 72 h apart. FKJC involves two ice bags, placed on the anterior and posterior surfaces of the knee, whereas the control condition received a plastic ice bag filled with candy corn. We assessed isometric and isokinetic (concentric and eccentric) quadriceps strength at two different velocities (60°/s and 180°/s). Participants performed three maximal voluntary contractions for each mode of muscle contraction, before and after each treatment (immediately, 20, and 40 min after). The outcome variable was maximum knee extension peak torque. FKJC did not change peak torque during any mode of muscle contraction (p > 0.05). The current findings suggest that 20 min of FKJC does not change static (isometric) or dynamic (isokinetic) strength of the quadriceps. FKJC was neither beneficial nor harmful to static or dynamic muscular strength.

Adaptive changes in muscle activity after cryotherapy treatment: Potential mechanism for improvement the functional state in patients with multiple sclerosis

BACKGROUND

The available literature lacks data about the influence of whole body cryotherapy (WBC) on muscle activity in patients with sclerosis multiplex (MS).

OBJECTIVE

Assessment of the influence of the 20 WBC series on the surface electromyography (sEMG) signal and the relationship between it and the functional state in patients with MS.

METHODS

The study group was 114 of MS patients (aged 45.24±11.88yr.,) which 74 of them received 20 of WBC. An assessment was made of: the hand grip (HGS), Timed 25-Foot Walk, Fatigue Severity Scale, sEMG signal from the dominant limb.

RESULTS

After a series of 20 WBC: in the rest electromyograms, an increase of extensor carpi radialis (ECR) and a decrease of flexor carpi radialis (FCR) amplitude were demonstrated (non-normalized signal ECR p = 0.0001); significant differences in sEMG rest signals between ECR and FCR have decreased; for voluntary contraction in both assessed antagonistic muscle amplitude was significantly decreased (p = 0.0005; p = 0.0316, p = 0.0185); an increase of HGS (p < 0.001); gait improvement (p = 0.001); decrease fatigue (p = 0.024). No significant changes were observed in the control group.

CONCLUSIONS

Series of 20 WBC improves the functional state and reduces fatigue in patients with MS, which may be due to adaptive changes in bioelectrical muscle activity.