Neuromuscular electrical stimulation (NMES) reduces structural and functional losses of quadriceps muscle and improves health status in patients with knee osteoarthritis

Developing a device for simultaneously investigating pivoting neuromuscular control and muscle properties toward a multi-axis rehabilitation

Understanding the pivoting neuromuscular control of the lower limb and its associated muscle properties is critical for developing diagnostic and rehabilitation tools. However, to the best of our knowledge, a device that can evaluate these factors simultaneously remains lacking. To address this gap, a device that can investigate pivoting neuromuscular control and associated muscle properties was developed in this study. The proposed device consisted of a pivoting mechanism and height-adjustable chair with a brace interface. The device can control a footplate at various speeds to facilitate pivoting stretching and quantify neuromuscular control. Time-synchronized ultrasonographic images can be acquired simultaneously to quantify muscle properties during both active and passive pivoting movements. The muscle displacement, fascicle length/displacement, pennation angle, pivoting stiffness, and pivoting instability were investigated using the proposed device. Further, the feasibility of the device was demonstrated through a cross-sectional study with healthy subjects. The proposed device successfully quantified changes in muscle displacement during passive and active pivoting movements, pivoting stiffness during passive movements, and neuromuscular control during active movements. Therefore, the proposed device is expected to be used as a research and therapeutic tool for improving pivoting neuromuscular control and muscle functions and investigating the underlying mechanisms associated between muscle properties and joint movement in the transverse plane.

Effect of muscle length on maximum evoked torque, discomfort, contraction fatigue, and strength adaptations during electrical stimulation in adult populations: A systematic review

Neuromuscular electrical stimulation (NMES) can improve physical function in different populations. NMES-related outcomes may be influenced by muscle length (i.e., joint angle), a modulator of the force generation capacity of muscle fibers. Nevertheless, to date, there is no comprehensive synthesis of the available scientific evidence regarding the optimal joint angle for maximizing the effectiveness of NMES. We performed a systematic review to investigate the effect of muscle length on NMES-induced torque, discomfort, contraction fatigue, and strength training adaptations in healthy and clinical adult populations (PROSPERO: CRD42022332965). We conducted searches across seven electronic databases: PUBMED, Web of Science, EMBASE, PEDro, BIREME, SCIELO, and Cochrane, over the period from June 2022 to October 2023, without restricting the publication year. We included cross-sectional and longitudinal studies that used NMES as an intervention or assessment tool for comparing muscle lengths in adult populations. We excluded studies on vocalization, respiratory, or pelvic floor muscles. Data extraction was performed via a standardized form to gather information on participants, interventions, and outcomes. Risk of bias was assessed using the Revised Cochrane risk-of-bias tool for cross-over trials and the Physiotherapy Evidence Database scale. Out of the 1185 articles retrieved through our search strategy, we included 36 studies in our analysis, that included 448 healthy young participants (age: 19-40 years) in order to investigate maximum evoked torque (n = 268), contraction fatigability (n = 87), discomfort (n = 82), and muscle strengthening (n = 22), as well as six participants with spinal cord injuries, and 15 healthy older participants. Meta-analyses were possible for comparing maximal evoked torque according to quadriceps muscle length through knee joint angle. At optimal muscle length 50° - 70° of knee flexion, where 0° is full extension), there was greater evoked torque during nerve stimulation compared to very short (0 - 30°) (p<0.001, CI 95%: -2.03, -1.15 for muscle belly stimulation, and -3.54, -1.16 for femoral nerve stimulation), short (31° - 49°) (p = 0.007, CI 95%: -1.58, -0.25), and long (71° - 90°) (p<0.001, CI 95%: 0.29, 1.02) muscle lengths. At long muscle lengths, NMES evoked greater torque than very short (p<0.001, CI 95%: -2.50, -0.67) and short (p = 0.04, CI 95%: -2.22, -0.06) lengths. The shortest quadriceps length generated the highest perceived discomfort for a given current amplitude. The amount of contraction fatigability was greater when muscle length allowed greater torque generation in the pre-fatigue condition. Strength gains were greater for a protocol at the optimal muscle length than for short muscle length. The quality of evidence was very high for most comparisons for evoked torque. However, further studies are necessary to achieve certainty for the other outcomes. Optimal muscle length should be considered the primary choice during NMES interventions, as it promotes higher levels of force production and may facilitate the preservation/gain in muscle force and mass, with reduced discomfort. However, a longer than optimal muscle length may also be used, due to possible muscle lengthening at high evoked tension. Thorough understanding of these physiological principles is imperative for the appropriate prescription of NMES for healthy and clinical populations.

Differences in ankle and knee muscle architecture and plantar pressure distribution among women with knee osteoarthritis

BACKGROUND

The aim of this study was to compare the plantar pressure distribution and knee and ankle muscle architecture in women with and without knee osteoarthritis (OA).

METHODS

Fifty women with knee OA (mean age = 52.11 ± 4.96 years, mean Body mass index (BMI) = 30.94 ± 4.23 kg/m2) and 50 healthy women as a control group (mean age = 50.93 ± 3.78 years, mean BMI = 29.06 ± 4.82 kg/m2) were included in the study. Ultrasonography was used to evaluate knee and ankle muscles architecture and femoral cartilage thickness. The plantar pressure distribution was evaluated using the Digital Biometry Scanning System and Milleri software (DIASU, Italy). Static foot posture was evaluated using the Foot Posture Index (FPI), and pain severity was assessed using the Visual Analog Scale.

RESULTS

The OA group exhibited lower muscle thickness in Rectus Femoris (RF) (p = 0.003), Vastus Medialis (VM) (p = 0.004), Vastus Lateralis (p = 0.023), and Peroneus Longus (p = 0.002), as well as lower Medial Gastrocnemius pennation angle (p = 0.049) and higher Fat thickness (FT) in RF (p = 0.033) and VM (p = 0.037) compared to the control group. The OA group showed thinner femoral cartilage thickness (p = 0.001) and higher pain severity (p = 0.001) than the control groups. FPI scores were higher (p = 0.001) in OA group compared to the control group. The plantar pressure distribution results indicated an increase in total surface (p = 0.027), total load (p = 0.002), medial load (p = 0.005), and lateral load (p = 0.002) on dominant side in OA group compared to the control group.

CONCLUSIONS

Knee and ankle muscle architecture, knee extensor muscle FT, and plantar pressure distribution in the dominant foot differed in individuals with knee OA compared to the control group.

Efficacy and safety of sodium hyaluronate combined with celecoxib for knee osteoarthritis: A systematic review and meta-analysis

Due to the large cost of joint replacement for surgical treatment of knee osteoarthritis, there are many complications in elderly patients, and there are many contraindications to surgery, and conservative treatment is still based on drugs. To further evaluate the efficacy and safety of sodium hyaluronate combined with celecoxib for the treatment of osteoarthritis of the knee. In total, 202 studies were screened, with a final selection of 9 RCTs involving 2339 participants; of these, 9 RCTs were included in the final meta-analysis. Treatment group reduces VAS (SMD = -1.61; 95 % CI [-2.25, -0.98]; I2 = 95 %; P < 0.00001) and adverse reactions (OR = 0.45; 95 % CI [0.22,0.94]; I2 = 0 %; P < 0.33); Meanwhile, improving Lysholm knee scores (SMD = 0.19; 95 % CI [-0.06, -0.44]; I2 = 76 %; P = 0.0004) and Clinical efficiency (OR = 0.31; 95 % CI [0.19,0.50]; I2 = 0 %; P < 0.00001). All indicators were superior to the control group. Our primary findings suggest that KOA treatment with celecoxib combined with sodium hyaluronate reduces VAS, while improving Lysholm scores and Clinical efficiency. In addition, we found that celecoxib combined with sodium hyaluronate treatment had fewer adverse effects than the control group, indicating that the combination is safe and effective in the treatment of KOA.

A controlled randomized trial with a 12-week follow-up investigating the effects of medium-frequency neuromuscular electrical stimulation on pain, VMO thickness, and functionality in patients with knee osteoarthritis

BACKGROUND

One of the major contributors to disability in Knee osteoarthritis (KOA) patients is weakness in the Quadriceps Femoris muscle. Neuromuscular electrical stimulation (NMES) has been used in rehabilitation for patients suffering from muscle weakness. Thus, the purpose of the study was to assess the effectiveness of NMES and exercise therapy, for improving pain, muscle weakness and function among patients with KOA.

METHODS

A randomized controlled trial was conducted with 75 female patients diagnosed with KOA. Participants were divided into three intervention groups: NMES-only, exercise therapy (Exs) alone, and a combination of NMES and exercise (NMES + Exs). All patients underwent 12 supervised treatment sessions, three times a week. Outcome measures included pain intensity measured by visual analog scale (VAS), knee flexion range of motion (FROM), thigh muscle girth (TG), thickness of the Vastus Medialis Oblique (VMO), timed up and go test (TUG), six-minute walk test (6MWT), and WOMAC scores. Statistical analyses (ANOVA and Kruskal-Wallis) methods were done to compare the amounts at the baseline, immediately after treatment and after 12 weeks.

RESULTS

The NMES group exhibited a significant reduction in pain at the 12-week follow-up compared to the other groups(p = 0.022). The NMES + Exs group showed better outcomes in terms of FROM, TG, and VMO thickness post-intervention (p < 0.0001, p < 0.004, p = 0.003, respectively) and at the 12-week follow-up (p < 0.0001, p < 0.0001, p < 0.0001, respectively). Additionally, NMES was superior in improving TUG and 6MWT post-intervention (p < 0.0001, p = 0.038, respectively) and during the follow-up assessments (p < 0.0001, p = 0.029, respectively). The NMES + Exs group achieved better WOMAC stiffness scores at both post-intervention and follow-up evaluations (p < 0.0001, p < 0.0001, respectively). Furthermore, at the 12-week follow-up, NMES + Exs group outperformed the others in WOMAC pain and function subscales (p = 0.003, p = 0.017, respectively), while the NMES group demonstrated better WOMAC total scores compared to the other groups (p = 0.007).

CONCLUSION

The combination of NMES and exercise seems to be an efficient approach for managing KOA, as it enhances knee flexion range and TG, increases VMO thickness, and improves WOMAC scores. On the other hand, NMES alone was found to be effective in improving the physical function of KOA patients.

TRIAL REGISTRATION

IRCT20101228005486N7 (06-02-2020).

The effect of neuromuscular electrical stimulation applied at different muscle lengths on muscle architecture and sarcomere morphology in rats

Neuromuscular electrical stimulation (NMES) is often used to increase muscle strength and functionality. Muscle architecture is important for the skeletal muscle functionality. The aim of this study was to investigate the effects of NMES applied at different muscle lengths on skeletal muscle architecture. Twenty-four rats were randomly assigned to four groups (two NMES groups and two control groups). NMES was applied on the extensor digitorum longus muscle at long muscle length, which is the longest and stretched position of the muscle at 170° plantar flexion, and at medium muscle length, which is the length of the muscle at 90° plantar flexion. A control group was created for each NMES group. NMES was applied for 8 weeks, 10 min/day, 3 days/week. After 8 weeks, muscle samples were removed at the NMES intervention lengths and examined macroscopically, and microscopically using a transmission electron microscope and streo-microscope. Muscle damage, and architectural properties of the muscle including pennation angle, fibre length, muscle length, muscle mass, physiological cross-sectional area, fibre length/muscle length, sarcomere length, sarcomere number were then evaluated. There was an increase in fibre length and sarcomere number, and a decrease in pennation angle at both lengths. In the long muscle length group, muscle length was increased, but widespread muscle damage was observed. These results suggest that the intervention of NMES at long muscle length can increase the muscle length but also causes muscle damage. In addition, the greater longitudinal increase in muscle length may be a result of the continuous degeneration-regeneration cycle.

Spatiotemporal and kinematic gait analysis in patients with knee osteoarthritis and femoral varus deformity

BACKGROUND

Knee osteoarthritis (OA) is commonly combined with the presentation of a coronal deformity of the knee. The bony origin of the knee varus deformity can be classified as tibial origin, femoral origin, or a combination of tibial and femoral causes. Deformities of tibial origin are mostly common clinically, while patients with knee OA with femoral varus deformity are less common.

RESEARCH QUESTION

Do hip, knee and ankle kinematics and spatiotemporal parameters differ between patients with knee OA with femoral varus deformity and healthy subjects?

METHODS

Twenty-five patients (14 females and 11 males) with knee OA and femoral varus deformity and 20 healthy subjects (12 males and 8 females) as control group were included in this study. The kinematic parameters of the hip-knee-ankle joint and spatiotemporal gait parameters were included in the study.

RESULTS

This study found that the step speed and step length of the knee OA with femoral varus (KOAF) group were smaller than those of the control group, while double support period percentage was greater in the KOAF group. Significant differences were found in the maximum knee extension angle, maximum knee flexion angle, knee flexion range of motion, maximum hip flexion angle, maximum hip extension angle, and hip flexion range of motion between the two groups. After comparing the ankle motion between the two groups, significant differences were found in the maximum eversion angle, inversion range of motion, maximum ankle abduction angle, and abduction range of motion.

SIGNIFICANCE

Knee OA with femoral varus deformity causes adaptive changes in the kinematic parameters of hip, knee and ankle joints and spatiotemporal gait parameters to alleviate symptoms and maintain normal activity.

Muscle Architecture and Subcutaneous Fat Measurements of Rectus Femoris and Vastus Lateralis at Optimal Length Aided by a Novel Ultrasound Transducer Attachment

Purpose: This cross-sectional study determines the sensitivity of muscle architecture and fat measurements of the rectus femoris (RF) and vastus lateralis (VL) muscles from ultrasound images acquired with varying transducer tilt, using a novel transducer attachment, in healthy adults. Secondary objectives were to estimate intrarater and interrater reliability of image measurement and acquisition, respectively. Methods: Thirty healthy adults participated (15 women and 15 men; 25 [SD 2.5] y). Ultrasound image acquisition was conducted by two raters at different transducer tilts relative to the skin: estimated perpendicular, and five measured angles (80°, 85°, 90°, 95°, 100°) using the transducer attachment. Muscle thickness (MT), subcutaneous fat thickness (FT), pennation angle (PA), and fascicle length (FL) were measured. Sensitivity and reliability were assessed using intra-class correlation coefficients (ICCs) and standard error of measurements (SEMs). Results: MT and FT for RF and VL were not sensitive to transducer tilt. However, PA and FL were sensitive to transducer tilt. MT and FT for both muscles showed high ICCs and low SEMs for intrarater and interrater reliability. For PA of both muscles, standardizing transducer tilt improved interrater ICCs and lowered SEMs. Conclusion: MT and FT measurements of RF and VL acquired at 60° knee flexion are robust to varying transducer tilt angles. PA measurements benefit from standardizing transducer tilt.

Physiotherapeutic Strategies and Their Current Evidence for Canine Osteoarthritis

Osteoarthritis (OA) is a common and debilitating condition in domestic dogs. Alongside pharmaceutical interventions and weight loss, exercise and physiotherapy (PT) are important measures in maintaining patient mobility and quality of life. Physiotherapy for OA aims to reduce pain, optimize muscular function and maintain joint function. Physiotherapeutic plans typically include PT exercises combined with therapeutic modalities, lifestyle and environmental modifications to improve the patient's overall quality of life and function. Information on therapeutic clinical efficacy of physiotherapeutic measures for canine OA is still very limited. Thus, physiotherapeutic strategies are still primarily based on evidence extrapolated from human protocols tailored to people with OA. The authors propose a simple systematic PT approach for canine OA, prioritizing measures according to simplicity, cost effectiveness and practicality. This guide (the "Physiotherapy Pyramid") aims to provide a clear stratified approach to simplify decision making and planning for owners, veterinarians and veterinary physiotherapists, leading to more straightforward design and implementation of treatment plans. Measures are implemented starting at the base of the pyramid, subsequently progressing to the top, allowing effective and practical interventions to be prioritized. The levels of the pyramid are in ascending order: environmental modification, exercise plan, OA-specific home exercises and treatment by a veterinary physiotherapist.

Systematic Review and Network Meta-analysis of Acupuncture Combined with Massage in Treating Knee Osteoarthritis

Background

Knee osteoarthritis is a common clinical disease with frequent occurrence. More and more studies have shown that external therapies such as acupuncture and massage are beneficial to the treatment of knee osteoarthritis.

Objective

The purpose of this systematic review and meta-analysis of randomized controlled trials (RCTS) was to evaluate the efficacy and safety of acupuncture and massage combined with treatment of KOA and to provide some reference for clinical treatment of KOA.

Methods

Network meta-analysis was used to evaluate the efficacy of acupuncture combined with massage in the treatment of knee osteoarthritis. PubMed, Cochrane Library, Web of Science, Embase, Chinese Knowledge Infrastructure (CNKI), Chinese Biomedical Literature Database (CBM), VIP, and Wanfang were searched by computer for randomized controlled trials on acupuncture combined with massage in the treatment of knee osteoarthritis. All researchers independently screened the literature, extracted data, and evaluated quality, and studies that met the quality criteria were analyzed using Stata16.0 software.

Results

A total of 3076 articles were retrieved, and finally, 49 studies involving 10 acupuncture combined with massage methods were included. The total sample size was 4458, including 2182 in the experimental group and 2276 in the control group. The results of network meta-analysis showed the following: in terms of effective rate, the optimal first three interventions were floating needle+massage, needle knife+massage, and silver needle+massage; in terms of reducing VAS score, the optimal first three interventions were common acupuncture+massage, needle knife+massage, and warm needle+massage; in terms of improving total Lysholm index score, the optimal first three interventions were silver needle+massage, electroacupuncture+massage, and needle knife+massage; in terms of reducing total WOMAC score, the optimal first three interventions were silver needle+massage, electrothermal needle+massage, and common acupuncture+massage; in terms of reducing WOMAC stiffness score, the optimal first three interventions were warm needle+massage, silver needle+massage, and common acupuncture+massage; and in terms of reducing WOMAC joint function score, the optimal first three interventions were silver needle+massage, warm needle+massage, and common acupuncture+massage.

Conclusion

The results showed that acupuncture combined with massage could improve the clinical therapeutic effect of patients with knee osteoarthritis. Limited by the quality of the included studies, the conclusions obtained still need to be further validated.

Modulation in the Stiffness of Specific Muscles of the Quadriceps in Patients With Knee Osteoarthritis and Their Relationship With Functional Ability

Deficits in the flexibility of the quadriceps are one of the risk factors for developing knee joint disorders. No studies have investigated the changes in the stiffness of the quadriceps muscle among patients with knee osteoarthritis (OA). Therefore, the purpose of this study was to investigate changes in the stiffness of specific-muscle of the quadriceps in patients with knee OA and their relationship with functional ability. Twenty-five patients with knee OA and 25 healthy, asymptomatic subjects were recruited in this study. The stiffness of the vastus lateralis (VL), vastus medialis (VM) and rectus femoris (RF) in all participants was evaluated using MyotonPRO at 60° and 90° flexion of the knee joint. The results of this study showed a greater VL stiffness in patients with knee OA than in healthy subjects at both 60° and 90° of knee flexion (p &lt; 0.05). Significant differences in VL, VM and RF stiffness were obtained at different knee joint angles in individuals with and without knee OA (p &lt; 0.05). In addition, there was a positive correlation between VL stiffness and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores in patients with Knee OA (60° of knee flexion: r = 0.508, p = 0.010; 90° of knee flexion: r = 0.456, p = 0.022). These results indicate that there is an increase in VL stiffness in patients with knee OA compared with healthy, asymptomatic subjects, and the quadriceps stiffness was increased with knee flexion in both healthy subjects and patients with knee OA. VL stiffness is associated with WOMAC scores in patients with knee OA.

Attenuation of cartilage pathogenesis in osteoarthritis by blocking the phosphorylation of tyrosine kinase Fyn to β-catenin, AZD0530

OBJECTIVE

To observe the effect of AZD0530 on the progression of knee OA after blocking β-catenin phosphorylation and then dormancy of the Wnt/β pathway by tyrosine kinase Fyn.

METHODS

The levels of Fyn, β-catenin, p-β-catenin (Tyr142), the chondrocyte positive marker Aggrecan, and the chondrocyte negative marker MMP13 were observed in human knee tibial plateau chondrocytes in vivo and in vitro. Different doses of AZD0530 were used to treat chondrocytes of the human OA tibial plateau chondrocytes in vitro, and the degree of chondrocyte degeneration was observed. Different doses of AZD0530 were intraarticularly injected into OA rats to observe the degree of tibial plateau cartilage degeneration.

RESULTS

When OA occurred in human knee, the levels of tyrosine kinase Fyn,β-catenin and p-β-catenin (Tyr142) in chondrocytes increased significantly.The level of Aggrecan decreased and MMP13 increased in chondrocytes. The levels of β-catenin, p-β-catenin (Tyr142) and MMP13 in chondrocytes decreased, while the level of Aggrecan increased after AZD0530 was used to intervene chondrocytes in vitro, which was positively correlated with the dose of AZD0530. Intra-articular injection of AZD0530 obviously attenuated the degeneration of articular cartilage, which was positively correlated with the dose of AZD0530.

CONCLUSION

The level of Fyn in chondrocytes of human knee tibial plateau increased significantly when OA occurred. AZD0530 can inhibit tyrosine kinase Fyn from β-catenin phosphorylation, a key Wnt/β pathway protein, and then inhibit Wnt/β pathway levels in chondrocytes. This finding also suggests that disruption of the Wnt/β pathway with AZD0530 provides chondral protection in rat posttraumatic OA.

Development and reliability of a new system for bedside evaluation of non-volitional knee extension force

PURPOSE

Neuromuscular electrical stimulation (NMES) is a widely-used technique for diagnostic and therapeutic purposes. Here we developed and tested the reliability of a new NMES-dynamometer system for bedside evaluation of knee extensor muscle function.

MATERIALS AND METHODS

Thirty-two healthy participants (16 men, 16 women; 27±5 years) completed two testing sessions, 7 days apart. On day 1, a single experienced rater, who repeated the evaluation on day 2 with two other raters, completed a standardized testing procedure. Participants were placed supine, with knees flexed and legs connected to the dynamometer. Maximal voluntary knee extensor isometric force (MVF) and supramaximal twitch force (TwF) were obtained.

RESULTS

High intra-rater intraclass correlation coefficients were observed for both MVF (0.91) and TwF (0.94). MVF and TwF standard error of measurements (8.2%, 5.9%) and minimal detectable changes (16%, 11.6%) were low compared to mean values. High intraclass correlation coefficients were also observed for inter-rater comparisons of MVF (0.89) and TwF (0.86). Standard errors of measurements (MVF: 8.7%, TwF: 5.5%) and minimal detectable changes (MVF: 17.2%, TwF: 10.8%) were similar to intra-rater comparisons.

CONCLUSION

The good reliability of the novel NMES-dynamometer system suggests it as an appropriate tool for the bedside evaluation of knee extensor muscle function.

Recommendations to Increase Neuromuscular Electrical Stimulation Training Intensity During Quadriceps Treatments for Orthopedic Knee Conditions

Neuromuscular electrical stimulation (NMES) is often used by clinicians as a therapeutic adjunct to improve quadriceps strength deficits following orthopedic knee conditions. The efficacy of NMES treatments is primarily dependent on the NMES training intensity, which is a direct result of NMES-induced torque production. The importance of NMES training intensity is well known, yet adequate NMES training intensities are often difficult to achieve due to a variety of limitations associated with NMES (eg, fatigue and patient discomfort). This article provides recommendations that a clinician can use to increase NMES training intensity when strengthening the quadriceps with NMES for orthopedic knee conditions. These recommendations should allow forceful contractions that can be sustained over a treatment with multiple repetitions without the rapid decline in force that is typically seen when NMES is used.

A systematic review of using electrical stimulation to improve clinical outcomes after hip fractures

BACKGROUND

Pain and muscles weakness often delays regaining independent mobility following hip fracture surgery. Electrical stimulation may relieve pain and improve muscle strength and function.

PURPOSE

To systematically review and evaluate available literature examining the effectiveness of using electrical stimulation to promote clinical outcomes after hip fractures.

METHODS

Two researchers independently searched MEDLINE, CINAHL, EMBASE, Web of Science, Cochrane Reviews, Physiotherapy Evidence Database, and PsycInfo from inception to July 1, 2018, with no restrictions. The quality and fidelity of the included interventions were assessed, and expert consultation was conducted to help explain the results.

RESULTS

We identified 432 records through database searching. Initial screening indicated 24 articles were appropriate for full-text review, and four articles met the inclusion criteria. In included studies, electrical stimulation (i.e. TENS) reduced pain (mean difference (MD) = 3.3 points on 10-point Visual Analogue Scale, p < .001), improved range of motion (ROM) (MD: 25.7°, p < .001), and accelerated functional recovery immediately after hip fracture (p < .001). Conflicting evidence existed when using neuromuscular electrical stimulation to improve muscle strength and other functional outcomes (e.g. mobility); however, nine experts advised that longer-term interventions might be necessary to achieve significant improvment in muscle strength.

CONCLUSION

Available evidence, albeit limited, supports the early application of noninvasive electrical stimulation (e.g. TENS) for improving clinical outcomes (i.e. reducing pain, improving ROM, and accelerating functional recovery after hip fractures). We could not find conclusive evidence on the effectiveness of using electrical stimulation to improve muscle strength. This review establishes the need for future additional high-quality trials in this field.

The Effect of Quadriceps Muscle Length on Maximum Neuromuscular Electrical Stimulation Evoked Contraction, Muscle Architecture, and Tendon-Aponeurosis Stiffness

Muscle-tendon unit length plays a crucial role in quadriceps femoris muscle (QF) physiological adaptation, but the influence of hip and knee angles during QF neuromuscular electrical stimulation (NMES) is poorly investigated. We investigated the effect of muscle length on maximum electrically induced contraction (MEIC) and current efficiency. We secondarily assessed the architecture of all QF constituents and their tendon-aponeurosis complex (TAC) displacement to calculate a stiffness index. This study was a randomized, repeated measure, blinded design with a sample of twenty healthy men aged 24.0 ± 4.6. The MEIC was assessed in four different positions: supine with knee flexion of 60° (SUP60); seated with knee flexion of 60° (SIT60); supine with knee flexion of 20° (SUP20), and seated with knee flexion of 20° (SIT20). The current efficiency (MEIC/maximum tolerated current amplitude) was calculated. Ultrasonography of the QF was performed at rest and during NMES to measure pennation angle (θ_p) and fascicle length (L_f), and the TAC stiffness index. MEIC and current efficiency were greater for SUP60 and SIT60 compared to SUP20 and SIT20. The vastus lateralis and medialis showed lower θ_p and higher L_f at SUP60 and SIT60, while for the rectus femoris, in SUP60 there were lower θ_p and higher L_f than in all positions. The vastus intermedius had a similar pattern to the other vastii, except for lack of difference in θ_p between SIT60 compared to SUP20 and SIT20. The TAC stiffness index was greater for SUP60. We concluded that NMES generate greater torque and current efficiency at 60° of knee flexion, compared to 20°. For these knee angles, lengthening the QF at the hip did not promote significant change. Each QF constituent demonstrated muscle physiology patterns according to hip and/or knee angles, even though a greater L_f and lower θ_p were predominant in SUP60 and SIT60. QF TAC index stiffened in more elongated positions, which probably contributed to enhanced force transmission and slightly higher torque in SUP60. Our findings may help exercise physiologist better understand the impact of hip and knee angles on designing more rational NMES stimulation strategies.

Effects of Neuromuscular Electrical Stimulation Combined with Exercises versus an Exercise Program on the Physical Characteristics and Functions of the Elderly: A Randomized Controlled Trial

(1) Background-The application of neuromuscular electrical stimulation (NMES) combined with low-intensity exercise to the elderly can be more efficient than low-intensity exercise only in terms of delaying the loss of muscle mass. We aimed to assess the adjunct of NMES to low-intensity lower limb strengthening exercise to prevent falls in frail elderly for a relatively short period of 4 weeks. (2) Methods-Thirty elderly women aged 65 or above were randomly categorized into three groups: control group (CON, n = 8), exercise group (EX, n = 10), and NMES with exercise group (EX + NMES, n = 9). The exercise group took part in a lower limb strengthening exercise program for one hour three times a week for four weeks. Furthermore, the NMES with exercise group had added NMES stimulation when exercising. The limbs' muscle mass, body fat mass, calf circumference, grip force, five times sit-to-stand test, timed up-and-go test (TUG), one-leg stand test, and Y-balance test (YBT) were evaluated at baseline and 4 weeks after. (3) Results-Comparisons between the three groups showed that the TUG was significantly decreased and the YB was significantly increased in NMES with exercise group (p < 0.05). (4) Conclusions-These results suggested that a combination of NMES stimulation and exercises was more helpful in strengthening balance than exercises alone in the short term.

Achilles Tendon Adaptation to Neuromuscular Electrical Stimulation: Morphological and Mechanical Changes

It remains unclear whether neuromuscular electrical stimulation can induce sufficient tendon stress to lead to tendon adaptations. Thus, we investigated the effect of such a training program on the triceps surae muscle following the morphological and mechanical properties of the Achilles tendon. Eight men participated in a 12-week high-frequency neuromuscular electrical stimulation training program of the triceps surae muscle under isometric conditions. Ultrasonography was used pre- and post-intervention to quantify cross-sectional area, free length, and total length of the Achilles tendon, as well as the myotendinous junction elongation during a maximal isometric ramp contraction under plantar flexion. Neuromuscular electrical stimulation training does not lead to changes in Achilles tendon free and total length, cross-sectional area, or maximal elongation capacity. However, a significant increase was evidenced in maximal tendon force post-training (+25.2%). Hence, Young's Modulus and maximal stress were significantly greater after training (+12.4% and +23.4%, respectively). High-frequency neuromuscular electrical stimulation training induces repeated stress sufficient to lead to adaptations of mechanical properties of the Achilles tendon. Thus, this training technique may be of particular interest as a new rehabilitation method in tendinopathy management or to counteract the effect of hypo-activity.

Effectiveness of pre-surgical neuromuscular electrical stimulation on the recovery time of diaphyseal femoral fractures

Background/aims:

Quadriceps pathology is common in patients who have suffered diaphyseal femoral fractures because of the long waiting times before surgery, during which they remain immobilised. The aim of this study was to evaluate the effectiveness of neuromuscular electrical stimulation applied in the pre-surgical period on the recovery time of the patients.

Methods

Before surgical treatment, patients with closed diaphyseal femoral fractures were systematically distributed alternatively into an intervention group and a control group. The intervention group (n=22) received pre-surgical neuromuscular electrical stimulation and the control group (n=25) received conventional physiokinetic treatment.

Results

Age, gender proportions and time between admission and surgery were similar in both groups. Average treatment time was 14.14 ± 9.7 days. Recovery time (from surgery to medical discharge) was 111 ± 15.65 days for participants in the intervention group, and 139.36 ± 23.05 days for participants in the control group (P<0.0001). No differences were found between men and women nor between the fractured femur (right vs left).

Conclusions

The results highlight the value of neuromuscular electrical stimulation in the pre-surgical period for patients with diaphyseal femoral fractures, optimising their rehabilitation and facilitating a quicker return to their everyday lives.

New Guidelines for Electrical Stimulation Parameters in Adult Patients With Knee Osteoarthritis Based on a Systematic Review of the Current Literature

OBJECTIVE

The goal of this systematic review was to provide guidelines for treatment parameters regarding electrical stimulation by investigating its efficacy in improving muscle strength and decreasing pain in patients with knee osteoarthritis.

DESIGN

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses standard, three electronic databases (CINAHL, PubMed, and PEDro) and gray literature were used. Randomized control trials comparing electrical stimulation and conservative physical therapy were critically appraised using the 2005 University of Oxford standard.

RESULTS

Nine randomized control trials were included in our review. First, our review confirmed that neuromuscular electrical stimulation is the most effective electrical stimulation treatment in the management of knee OA, and its efficiency is higher when combined with a strengthening program. Second, frequency of at least 50 Hz and no more than 75 Hz with a pulse duration between 200 and 400 μs and a treatment duration of 20 mins is necessary for successful treatment.

CONCLUSIONS

For the first time, our review provides standardized clinical treatment parameters for neuromuscular electrical stimulation to be included in a strengthening program for the adult patient with knee OA.

TO CLAIM CME CREDITS

Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME CME OBJECTIVES: Upon completion of this article, the reader should be able to: (1) Recall the impact of quadriceps femoris weakness on joint stability; (2) Summarize the mechanism of action of neuromuscular electrical stimulation (NMES) on reducing pain and increasing muscle strength; and (3) Plan the clinical treatment parameters of NMES to be included in a strengthening program for an adult patient with knee osteoarthritis.

LEVEL

Advanced.

ACCREDITATION

The Association of Academic Physiatrists is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.The Association of Academic Physiatrists designates this Journal-based CME activity for a maximum of 1.0 AMA PRA Category 1 Credit(s)™. Physicians should only claim credit commensurate with the extent of their participation in the activity.

Russian and Low-Frequency Currents Induced Similar Neuromuscular Adaptations in Soccer Players: A Randomized Controlled Trial

CONTEXT

Neuromuscular electrical stimulation is widely used to induce muscular strength increase; however, no study has compared Russian current (RC) with pulsed current (PC) effects after a training program.

OBJECTIVES

We studied the effects of different neuromuscular electrical stimulation currents, RC, and PC on the neuromuscular system after a 6-week training period.

DESIGN

Blinded randomized controlled trial.

SETTING

Laboratory.

PATIENTS

A total of 27 male soccer players (age 22.2 [2.2] y, body mass 74.2 [10.0] kg, height 177 [0] cm, and body mass index 23.7 [2.9] kg/cm2 for the control group; 22.1 [3.1] y, 69.7 [5.7] kg, 174 [0] cm, and 23.0 [2.5] kg/cm for the PC group; and 23.0 [3.4] y, 72.1 [10.7] kg, 175 [0] cm, and 23.5 [3.4] kg/cm for the RC group) were randomized into 3 groups: (1) control group; (2) RC (2500 Hz, burst 100 Hz, and phase duration 200 μs); and (3) PC (100 Hz and 200 μs).

INTERVENTION

The experimental groups trained for 6 weeks, with 3 sessions per week with neuromuscular electrical stimulation.

MAIN OUTCOME MEASURES

Maximal voluntary isometric contraction and evoked torque, muscle architecture, sensory discomfort (visual analog scale), and electromyographic activity were evaluated before and after the 6-week period.

RESULTS

Evoked torque increased in the RC (169.5% [78.2%], P < .01) and PC (248.7% [81.1%], P < .01) groups. Muscle thickness and pennation angle increased in the RC (8.7% [3.8%] and 16.7% [9.0%], P < .01) and PC (16.1% [8.0%] and 27.4% [11.0%], P < .01) groups. The PC demonstrated lower values for visual analog scale (38.8% [17.1%], P < .01). There was no significant time difference for maximal voluntary isometric contraction and root mean square values (P > .05). For all these variables, there was no difference between the RC and PC (P > .05).

CONCLUSION

Despite the widespread use of RC in clinical practice, RC and PC training programs produced similar neuromuscular adaptations in soccer players. Nonetheless, as PC generated less perceived discomfort, it could be preferred after several training sessions.

Feasibility of eccentric overloading and neuromuscular electrical stimulation to improve muscle strength and muscle mass after treatment for head and neck cancer

PURPOSE

Treatment of head and neck cancer (HNC) results in severe weight loss, mainly due to the loss of lean body mass. Consequently, decreases in muscular strength and health-related quality of life (HRQL) occur. This study investigated the feasibility of a 12-week novel strength training (NST) and conventional strength training (CST) intervention delivered after HNC treatment.

METHODS

Participants were randomized to a NST group (n = 11) involving eccentric overloaded strength training and neuromuscular electrical stimulation (NMES), or a CST group (n = 11) involving dynamic resistance exercises matched for training volume. Feasibility outcomes included recruitment, completion, adherence, and evidence of progression. A neuromuscular assessment involving maximal isometric voluntary contractions (MIVCs) in the knee extensors was evaluated prior to and during incremental cycling to volitional exhaustion at baseline and after the interventions. Anthropometrics and patient-reported outcomes (PROs) were also assessed.

RESULTS

Although recruitment was challenging, completion was 100% in NST and 82% in CST. Adherence was 92% in NST and 81% in CST. Overall, MIVC increased by 19 ± 23%, muscle cross-sectional area improved 18 ± 22%, cycling exercise time improved by 18 ± 13%, and improvements in HRQL and fatigue were clinically relevant.

CONCLUSIONS

Both interventions were found to be feasible for HNC patients after treatment. Strength training significantly improved maximal muscle strength, muscle cross-sectional area, and PROs after HNC treatment. Future research should include fully powered trials and consider the use of eccentric overloading and NMES during HNC treatment.

IMPLICATIONS FOR CANCER SURVIVORS

Eccentric- and NMES-emphasized strength training may be useful alternatives to conventional strength training after HNC treatment.

Electrical Stimulation of Muscle: Electrophysiology and Rehabilitation

The generation of action potentials in intramuscular motor and sensory axons in response to an imposed external current source can evoke muscle contractions and elicit widespread responses throughout the nervous system that impact sensorimotor function. The benefits experienced by individuals exposed to several weeks of treatment with electrical stimulation of muscle suggest that the underlying adaptations involve several physiological systems, but little is known about the specific changes elicited by such interventions.

Home FES: An Exploratory Review

This review of literature focuses on the multiple uses of Functional Electrical Stimulation (FES) and how this modality may be a valuable home-based therapy. Papers pertaining to home FES exercise were collected using the Web of Science, Google Scholar databases and collegial hints. In our opinion, the following statements summarize the results. FES may be used to induce health benefits in populations with paralysis, and in persons with musculoskeletal, cardiorespiratory and renal pathology. The EU Project Rise showed how FES could have a variety of encouraging outcomes for patients with denervated muscles following traumatic injuries. As suggested by recent literature, FES has proven to be a viable form of exercise for elderly individuals. Thus, Home FES may be an option for patients looking for an additional form of muscle and cardiopulmonary physical therapy.

Randomised study of the effects of neuromuscular electrical stimulation and low-level laser therapy on muscle activation and pain in patients with knee osteoarthritis

Background

The combined effects of low-level laser therapy and neuromuscular electrical stimulation on knee osteoarthritis have yet to be analysed. This study aimed to determine the individual and combined effects of laser therapy and electrical stimulation on muscle activation and pain in older people with knee osteoarthritis.

Methods

A total of 45 women aged 60–75 years with knee osteoarthritis were randomised into three groups to receive stimulation, laser or stimulation plus laser therapy. All three groups underwent a 4-week control period (without intervention) followed by an 8-week intervention period. The effects of the interventions on muscle inhibition, electrical activity and pain were analysed.

Findings

There was a decrease in muscle inhibition (effect size ≥0.6) and a reduction in pain (effect size >1.2) in all three groups. All therapies generated an increase in electrical activity (effect size 0.1–0.5).

Conclusions

Laser alone or in combination with electrical stimulation promoted similar increases in muscle activation and pain relief.

Short-term effects of neuromuscular electrical stimulation and ultrasound therapies on muscle architecture and functional capacity in knee osteoarthritis: a randomized study

Objective:

To determine the effects of ultrasound therapy and neuromuscular electrical stimulation (NMES) application on the muscle architecture and functional capacity in patients with knee osteoarthritis.

Design:

A randomized study.

Subjects:

A total of 60 patients with knee osteoarthritis.

Interventions:

Participants were randomized into one of the following two intervention groups, five days a week, for three weeks: the combination of NMES application, hot pack, and exercise therapy was applied to the NMES group. The combination of therapeutic ultrasound, hot pack and exercise therapy was applied to the ultrasound therapy group.

Main measures:

Subjects were evaluated for pain and functional capacity with the use of the visual analog pain scale (VAS), Western Ontario and McMaster Universities Arthritis Index (WOMAC), and 15 meter walking test. The muscle architecture (muscle thickness, pennation angle and fascicle length) was assessed from vastus lateralis and quadriceps femoris muscles bilaterally by ultrasonography.

Results:

Two groups presented significant improvements in all outcome measures before and after treatment ( P < 0.01). There were significant improvements in VAS rest pain ( P < 0.05), VAS activity pain ( P < 0.05), WOMAC pain ( P < 0.05), WOMAC stiffness score ( P < 0.05), and WOMAC physical function ( P < 0.05) for the ultrasound therapy group in comparison to the NMES group. NMES group exhibited more increases in the muscle thickness and fascicle length values when compared to ultrasound therapy group ( P < 0.05).

Conclusion:

Ultrasound therapy appears to be an effective treatment in reducing pain and improving functional capacity. NMES application has more effects on the muscle architecture.

Localized muscle vibration reverses quadriceps muscle hypotrophy and improves physical function: a clinical and electrophysiological study

Quadriceps weakness has been associated with knee osteoarthritis (OA). High-frequency localized muscle vibration (LMV) has been proposed recently for quadriceps strengthening in patients with knee OA. The purpose of this study was (a) to investigate the clinical effectiveness of high-frequency LMV on quadriceps muscle in patients with knee OA and (b) to disentangle, by means of surface electromyography (sEMG), the underlying mechanism. Thirty patients, aged between 40 and 65 years, and clinically diagnosed with knee OA were included in this randomized, controlled, single-blinded pilot study. Participants were randomly assigned to two groups: a study group treated with LMV, specifically set for muscle strengthening (150 Hz), by means of a commercial device VIBRA, and a control group treated with neuromuscular electrical stimulation. Clinical outcome was measured using the Western Ontario and McMaster Universities Osteoarthritis Index, Visual Analogue Scale, knee range of motion, Timed Up and Go test, and Stair climbing test. To assess changes in muscle activation and fatigue a subgroup of 20 patients was studied with the use of sEMG during a sustained isometric contraction. The LMV group showed a significant change in Western Ontario and McMaster Universities Osteoarthritis Index score, Visual Analogue Scale score, Timed Up and Go test, Stair Climbing Test, and knee flexion. These improvements were not significant in patients treated with neuromuscular electrical stimulation. sEMG analysis suggested an increased involvement of type II muscle fibers in the group treated with LMV. In conclusion, the present study supports the effectiveness of local vibration in muscle function and clinical improvement of patients with knee OA.

Eccentric training combined to neuromuscular electrical stimulation is not superior to eccentric training alone for quadriceps strengthening in healthy subjects: a randomized controlled trial

BACKGROUND

Both eccentric training and neuromuscular electrical stimulation (NMES) are used for quadriceps strengthening. However, the effects of these interventions combined are unclear.

OBJECTIVES

To compare the effects of eccentric training combined to NMES and eccentric training alone on structure, strength, and functional performance of knee extensor muscles of healthy subjects.

METHODS

This is a three-arm, single-blinded, randomized controlled trial. Forty-three volunteers (18-35 years) completed the full study schedule: control group (n=15); eccentric training group (ECC; n=15); and eccentric training combined to NMES group (ECC+NMES; n=13). Eccentric training program was performed twice a week for 6 weeks. A biphasic pulsed current (400μs; 80Hz; maximal tolerated intensity) was applied simultaneously to voluntary exercise for ECC+NMES group. Muscle structure (ultrasonography of vastus lateralis - VL, and rectus femoris - RF), strength (isokinetic dynamometry) and functional capacity (single hop test) were assessed before and after the training program by blinded researchers to groups allocation.

RESULTS

Control group had no changes throughout the study in any outcome. Eccentric training (with or without NMES) did not affect concentric peak torque, hop test, and VL pennation angle (effect sizes>0.2). ECC and ECC+NMES programs generated significant adaptations (small to moderate effect sizes) on isometric (8-11%) and eccentric (13%) peak torques, VL muscle thickness (5%), VL fascicle length (5-8%), RF muscle thickness (8-9%), RF pennation angle (-2%), and RF fascicle length (12%).

CONCLUSION

NMES combined to eccentric training did not influence consistently the type or magnitude of adaptations provoked by knee extensor eccentric training alone in healthy subjects.

What Is Important Besides Getting the Bone to Heal? Impact on Tissue Injury Other Than the Fracture

Fracture surgeons do a great job of managing bone issues, but they may overlook the associated soft tissue injuries that play a significant role in the final outcome after musculoskeletal injury. The soft tissue reconstruction ladder can help guide reconstructive procedures based on the least complex procedure that allows the best chance of fracture healing. Muscle injury, volume loss, and deconditioning occur with traumatic injury and during the recovery phase. Neuromuscular stimulation, nutrition, and strength training are potential ways to aid in recovery. Complex periarticular knee injuries have a high rate of associated soft tissue injuries that may affect outcome if associated with knee instability. Identifying and addressing these injuries can increase the likelihood of a good outcome. Articular cartilage loss can make articular reconstruction impossible. Large fresh osteoarticular allografts can be a reconstructive option. Addressing all the damaged structures involved with a fracture may be the next step in improving patient outcomes.

Trunk Muscle Training Augmented With Neuromuscular Electrical Stimulation Appears to Improve Function in Older Adults With Chronic Low Back Pain: A Randomized Preliminary Trial

OBJECTIVES

To assess the feasibility of a trial to evaluate a trunk muscle training program augmented with neuromuscular electrical stimulation (TMT+NMES) for the rehabilitation of older adults with chronic low back pain (LBP) and to preliminarily investigate whether TMT+NMES could improve physical function and pain compared with a passive control intervention.

MATERIALS AND METHODS

We conducted a single-blind, randomized feasibility trial. Patients aged 60 to 85 years were allocated to TMT+NMES (n=31) or a passive control intervention (n=33), consisting of passive treatments, that is, heat, ultrasound, and massage. Outcomes assessed 3- and 6-month postrandomization included Timed Up and Go Test, gait speed, pain, and LBP-related functional limitation.

RESULTS

Feasibility was established by acceptable adherence (≥80%) and attrition (<20%) rates for both interventions. Both groups had similar, clinically important reductions in pain of >2 points on a numeric pain rating scale during the course of the trial. But, only the TMT+NMES group had clinically important improvements in both performance-based and self-reported measures of function. In terms of the participants' global rating of functional improvement at 6 months, the TMT+NMES group improved by 73.9% and the passive control group improved by 56.7% compared with baseline. The between-group difference was 17.2% (95% confidence interval, 5.87-28.60) in favor of TMT+NMES.

DISCUSSION

It seems that a larger randomized trial investigating the efficacy of TMT+NMES for the purpose of improving physical function in older adults with chronic LBP is warranted.

Phisical modalities on the functional performance in knee osteoarthritis: a sytematic review

Abstract Introduction: Despite recent advances in the treatment of osteoarthritis (OA), few studies have evaluated the longitudinal effect of physical modalities in functional capacity in patients with knee OA. Thereby, since the physical components and pain can affect the functional performance of daily activities, the effect of these treatment’s form is still to be established. Objective: Evaluate the effectiveness of therapeutic ultrasound, electrical stimulation and phototherapy in the functional performance, in patients with knee osteoarthritis. Methods: Articles present in the PubMed, Lilacs, SciELO and PEDro’s databases were evaluated. The used keywords were “pulsed ultrasound therapy”, “ultrasound therapy”, “electric stimulation” and “low level laser therapy” in combination with “knee osteoarthritis”. Were included in this presented review, randomized clinical studies using ultrasound, electrical and laser stimulation in subjects with knee osteoarthritis. To evaluate the methodological quality of the selected studies, was used the PEDro’s scale. The dependent variables of the study were: pain, physical function, joint stiffness, life quality and functional performance. Results: 268 studies were found, of these, 41 studies met eligibility criteria and were classified for analysis in full. The used methodology in the studies varied widely, however, in most cases there was improvement in functional performance of individuals with knee OA, with the use of physical modalities, for the pulsed ultrasound, continuous ultrasound, electrical stimulation and laser resourses. Conclusion: The physical modalities used in the studies demonstrated improvement in functional performance of individuals with knee OA.

Using the Hephaistos orthotic device to study countermeasure effectiveness of neuromuscular electrical stimulation and dietary lupin protein supplementation, a randomised controlled trial

Purpose

The present study investigated whether neuromuscular electrical stimulation for 20 min twice a day with an electrode placed over the soleus muscle and nutritional supplementation with 19 g of protein rich lupin seeds can reduce the loss in volume and strength of the human calf musculature during long term unloading by wearing an orthotic unloading device.

Methods

Thirteen healthy male subjects (age of 26.4 ± 3.7 years) wore a Hephaistos orthosis one leg for 60 days during all habitual activities. The leg side was randomly chosen for every subject. Six subjects only wore the orthosis as control group, and 7 subjects additionally received the countermeasure consisting of neuromuscular electrical stimulation of the soleus and lateral gastrocnemius muscles and lupin protein supplementation. Twenty-eight days before and on the penultimate day of the intervention cross-sectional images of the calf muscles were taken by magnetic resonance imaging (controls n = 5), and maximum voluntary torque (controls n = 6) of foot plantar flexion was estimated under isometric (extended knee, 90° knee flexion) and isokinetic conditions (extended knee), respectively.

Results

After 58 days of wearing the orthosis the percentage loss of volume in the entire triceps surae muscle of the control subjects (-11.9 ± 4.4%, mean ± standard deviation) was reduced by the countermeasure (-3.5 ± 7.2%, p = 0.032). Wearing the orthosis generally reduced plantar flexion torques values, however, only when testing isometric contraction at 90° knee ankle the countermeasure effected a significantly lower percentage decrease of torque (-9.7 ± 7.2%, mean ± SD) in comparison with controls (-22.3 ± 11.2%, p = 0.032).

Conclusion

Unloading of calf musculature by an orthotic device resulted in the expected loss of muscle volume and maximum of plantar flexion torque. Neuromuscular electrical muscle stimulation and lupin protein supplementation could significantly reduce the process of atrophy.

Trial registration

ClinicalTrials.gov, identifier NCT02698878

FKD, Paiva TD, Medeiros MCD, Caldas RTJ, Souza MCD. Impact of a three-month resistance training program for elderly persons with knee osteoarthritis residing in the community of Santa Cruz, Rio Grande do Norte, Brazil

Abstract Objective: to evaluate the impact of a three-month resistance exercise program on the pain and functionality of elderly patients with knee osteoarthritis from the city of Santa Cruz, Rio Grande do Norte. Method: a quasi-experimental study was performed with 13 elderly patients diagnosed with knee osteoarthritis, who underwent a resistance training program twice a week for 12 weeks. Pain, muscle strength, functionality, quality of life and patient satisfaction were evaluated using the following instruments: the visual analog scale, one repetition maximum testing, the Western Ontario and McMaster Universities Osteoarthritis Index, the Timed Up and Go Test, the 6-minute walk Test, the Short Form (36) Health Survey and the Likert scale. The paired T-test and ANOVA for repeated measures were used for statistical analysis. Results: the mean age of the patients was 62.0 (±10.0) years. At the end of the study, the pain, muscle strength, functional status and some areas of quality of life of the elderly had improved. Conclusion: resistance exercises were an effective and safe method of improving the pain, muscle strength, functionality and quality of life of the population studied. The elderly should be encouraged to perform supervised strength training therapy.

The effects of various physical non-operative modalities on the pain in osteoarthritis of the knee

The purpose of this study was to evaluate the effect of various non-operative modalities of treatment (transcutaneous electrical nerve stimulation (TENS); neuromuscular electrical stimulation (NMES); insoles and bracing) on the pain of osteoarthritis (OA) of the knee. We conducted a systematic review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to identify the therapeutic options which are commonly adopted for the management of osteoarthritis (OA) of the knee. The outcome measurement tools used in the different studies were the visual analogue scale and The Western Ontario and McMaster Universities Arthritis Index pain index: all pain scores were converted to a 100-point scale. A total of 30 studies met our inclusion criteria: 13 on insoles, seven on TENS, six on NMES, and four on bracing. The standardised mean difference (SMD) in pain after treatment with TENS was 1.796, which represented a significant reduction in pain. The significant overall effect estimate for NMES on pain was similar to that of TENS, with a SMD of 1.924. The overall effect estimate of insoles on pain was a SMD of 0.992. The overall effect of bracing showed a significant reduction in pain of 1.34. Overall, all four non-operative modalities of treatment were found to have a significant effect on the reduction of pain in OA of the knee. This study shows that non-operative physical modalities of treatment are of benefit when treating OA of the knee. However, much of the literature reviewed evaluates studies with follow-up of less than six months: future work should aim to evaluate patients with longer follow-up.

Electrically Elicited Muscle Torque: Comparison Between 2500-Hz Burst-Modulated Alternating Current and Monophasic Pulsed Current

STUDY DESIGN

Single-blind, block-randomization crossover design.

OBJECTIVE

To compare the knee extensor muscle torque production elicited with 2500-Hz burst-modulated alternating current (BMAC) and with a monophasic pulsed current (MPC) at the maximum tolerated stimulation intensity.

BACKGROUND

Neuromuscular electrical stimulation (NMES) is often used for strengthening the quadriceps following knee surgery. Strength gains are dependent on muscle torque production, which is primarily limited by discomfort. Burst-modulated alternating current stimulation is a clinically popular waveform for NMES. Prior research has established that MPC with a relatively long pulse duration is effective for high muscle torque production.

METHODS

Participants in this study were 20 adults with no history of knee injury. A crossover design was used to randomize the order in which each participant's dominant or nondominant lower extremity received NMES and the waveform (MPC or BMAC) this limb received. Stimulation intensity was incrementally increased until participants reached their maximum tolerance. The torque produced was converted to a percentage of each participant's maximum volitional isometric contraction of the respective limb.

RESULTS

A general linear model for a 2-treatment, 2-period crossover design was utilized to analyze the results. The mean ± SD electrically induced percent maximum volitional isometric contraction at maximal participant tolerance was 49.5% ± 19.6% for MPC and 29.8% ± 12.4% for BMAC. This difference was statistically significant (P = .002) after accounting for treatment order and limb, which had no effect on torque production.

CONCLUSION

Neuromuscular stimulation using MPC may be more efficacious than using BMAC to achieve a high torque output in patients with quadriceps weakness.

Self directed home based electrical muscle stimulation training improves exercise tolerance and strength in healthy elderly

Advancing age is associated with a gradual decline in muscle strength, exercise tolerance and subsequent capacity for activities of daily living. It is important that we develop effective strategies to halt this process of gradual decline in order to enhance functional ability and capacity for independent living. To achieve this, we must overcome the challenge of sustaining ongoing engagement in physical exercise programmes in the sedentary elderly population, particularly those who experience barriers to exercise participation. Recent developments in electrical muscle stimulation technology could provide a potential solution. In this pilot case-control study we investigated the effects of a self-directed home based programme of electrical muscle stimulation training on muscle strength and exercise tolerance in a group of 16 healthy elderly volunteers (10f, 6m). Study participants completed 30 separate 1-hour electrical muscle stimulation sessions at home over a 6-week period. We observed significant improvements in quadriceps muscle strength and 6-minute walk distance, suggesting that this form of electrical muscle stimulation training has promise as an exercise modality in the elderly population.

Musculoskeletal Atrophy in an Experimental Model of Knee Osteoarthritis: The Effects of Exercise Training and Low-Level Laser Therapy

OBJECTIVE

The aim of this study was to evaluate the effects of an exercise training protocol and low-level laser therapy (and the association of both treatments) on musculoskeletal atrophy using an experimental model of knee osteoarthritis (OA).

DESIGN

Fifty male Wistar rats were randomly divided into five groups: control group, knee OA control group, OA plus exercise training group, OA plus low-level laser therapy group, and OA plus exercise training associated with low-level laser therapy group. The exercise training and the laser irradiation started 4 wks after the surgery, 3 days per week for 8 wks. The exercise was performed at a speed of 16 m/min, 3 days per week, 50 mins per day, for 8 wks. Laser irradiation was applied at two points of the left knee joint (medial and lateral), for 24 sessions.

RESULTS

The results showed that both trained groups (irradiated or not) presented a significant increase in the muscle cross-sectional area and a decrease in muscle fiber density compared with the knee OA control group. Moreover, both trained and laser-irradiated groups demonstrated decreased muscle-specific ring-finger protein 1 and atrogin-1 immunoexpression.

CONCLUSIONS

These results suggest that exercise training and low-level laser therapy were effective in preventing musculoskeletal alterations related to atrophy caused by the degenerative process induced by knee OA.

Efeitos de oito semanas de treinamento com estimulação elétrica neuromuscular nas razões de ativação muscular / torque de idosas com osteoartrite

Introdução: O envelhecimento causa prejuízos no sistema musculoesquelético que podem ocasionar a osteoartrite, provocando degeneração da cartilagem articular e, consequentemente, perdas funcionais a idosos acometidos. Por outro lado, a estimulação elétrica neuromuscular é utilizada como treinamento para fortalecimento muscular.Objetivo: Investigar o efeito de oito semanas de treinamento com neuromuscular electrical stimulation (NMES) nas razões de ativação root mean square (RMS) / torque dos músculos extensores do joelho em idosas com osteoartrite. Metodologia: Vinte e quatro idosas foram divididas em dois grupos: grupo saudável (SAU; n=12) e grupo osteoartrite (OA; n=12). O grupo OA foi submetido a oito semanas de treinamento com NMES e tempo de aplicação variando de 18 a 32 minutos e frequência semanal de três vezes.Resultados: No grupo OA, ocorreu um aumento dos valores RMS pós-treinamento comparado com o pré-treinamento (p<0,05). O grupo SAU permaneceu igual ao grupo OA pós-treinamento (p>0,05). O torque do quadríceps aumentou pós-treinamento no grupo OA no ângulo de 90° de flexão do joelho, contudo, o grupo SAU apresentou maior produção de torque em todos os ângulos avaliados (p<0,05). No grupo OA, houve aumento das razões RMS / torque após o treinamento para os ângulos de 60º, 75º e 90º de flexão do joelho (p<0,05), mas não diferindo do grupo SAU (p>0,05).Conclusão: Oito semanas de treinamento com NMES aumentaram a ativação muscular e torque dos músculos extensores do joelho no grupo osteoartrite, mas não foram capazes de gerar adaptações suficientes para igualar os mesmos ao grupo saudável.

Impact of Varying the Parameters of Stimulation of 2 Commonly Used Waveforms on Muscle Force Production and Fatigue

STUDY DESIGN

Laboratory-based experimental study using a repeated-measures design.

OBJECTIVES

To determine the effect of varying stimulation parameters of burst-modulated alternating current (BMAC) and pulsed current (PC) on quadriceps femoris muscle force output and fatigue.

BACKGROUND

The impact of altering stimulation parameters on muscle force and fatigue using PC has been well described; however, less is known regarding BMAC.

METHODS

Quadriceps femoris muscle force was measured during a series of neuromuscular electrical stimulation-induced muscle contractions, with varying combinations of pulse duration and frequency, using PC or varying duty cycles and burst frequencies using BMAC. Additionally, muscle fatigue tests were conducted bilaterally with different stimulation waveforms and parameters.

RESULTS

For PC, the product of pulse duration and frequency was strongly predictive of muscle force output (R(2) = 0.85, P<.05). When using BMAC, the duty cycle was a strong predictor of force output (R(2) = 0.91, P<.05). Altering the frequency during BMAC had no effect on muscle force production, as opposed to the classic force-frequency relationship consistently observed with PC. Waveform type significantly impacts muscle fatigue, the BMAC resulted in a more rapid rate of fatigue irrespective of stimulation frequency, and it was confirmed again that lower frequencies of PC result in less fatigue during repeated muscle contractions.

CONCLUSION

In this study, altering the burst frequency of BMAC did not influence muscle force or fatigue, whereas the duty cycle significantly impacted muscle force production. Frequency of PC impacted both force and fatigue as expected, demonstrating increased muscle force and fatigue with increased frequency.

Physical rehabilitation improves muscle function following volumetric muscle loss injury

Background

Given the clinical practice of prescribing physical rehabilitation for the treatment of VML injuries, the present study examined the functional and histomorphological adaptations in the volumetric muscle loss (VML) injured muscle to physical rehabilitation.

Methods

Tibialis anterior muscle VML injury was created in Lewis rats (n = 32), and were randomly assigned to either sedentary (SED) or physical rehabilitation (RUN) group. After 1 week, RUN rats were given unlimited access to voluntary running wheels either 1 or 7 weeks (2 or 8 weeks post-injury). At 2 weeks post-injury, TA muscles were harvested for molecular analyses. At 8 weeks post-injury, the rats underwent in vivo function testing. The explanted tissue was analyzed using histological and immunofluorescence procedures.

Results

The primary findings of the study are that physical rehabilitation in the form of voluntary wheel running promotes ~ 17% improvement in maximal isometric torque, and a ~ 13% increase in weight of the injured muscle, but it did so without significant morphological adaptations (e.g., no hypertrophy and hyperplasia). Wheel running up-regulated metabolic genes (SIRT-1, PGC-1α) only in the uninjured muscles, and a greater deposition of fibrous tissue in the defect area of the injured muscle preceded by an up-regulation of pro-fibrotic genes (Collagen I, TGF-β1). Therefore, it is plausible that the wheel running related functional improvements were due to improved force transmission and not muscle regeneration.

Conclusions

This is the first study to demonstrate improvement in functional performance of non-repaired VML injured muscle with physical rehabilitation in the form of voluntary wheel running. This study provides information for the first time on the basic changes in the VML injured muscle with physical rehabilitation, which may aid in the development of appropriate physical rehabilitation regimen(s).

Effects of neuromuscular electrical stimulation and low-level laser therapy on the muscle architecture and functional capacity in elderly patients with knee osteoarthritis: a randomized controlled trial

Objectives:

To determine the effects of low-level laser therapy in combination with neuromuscular electrical stimulation on the muscle architecture and functional capacity of elderly patients with knee osteoarthritis.

Design:

A randomized, evaluator-blinded clinical trial with sequential allocation of patients to three different treatment groups.

Setting:

Exercise Research Laboratory.

Subjects:

A total of 45 elderly females with knee osteoarthritis, 2-4 osteoarthritis degrees, aged 66–75 years.

Intervention:

Participants were randomized into one of the following three intervention groups: electrical stimulation group (18–32 minutes of pulsed current, stimulation frequency of 80 Hz, pulse duration of 200 μs and stimulation intensity fixed near the maximal tolerated), laser group (low-level laser therapy dose of 4–6 J per point, six points at the knee joint) or combined group (electrical stimulation and low-level laser therapy). All groups underwent a four-week control period (without intervention) followed by an eight-week intervention period.

Main measures:

The muscle thickness, pennation angle and fascicle length were assessed by ultrasonography, and the functional capacity was assessed using the 6-minute walk test and the Timed Up and Go Test.

Results:

After intervention, only the electrical stimulation and combined groups exhibited significant increases in the muscle thickness (27%–29%) and pennation angle (24%–34%) values. The three groups exhibited increased performance on the walk test (5%–9%). However, no significant differences in terms of functional improvements were observed between the groups.

Conclusions:

Neuromuscular electrical stimulation reduced the deleterious effects of osteoarthritis on the quadriceps structure. Low-level laser therapy did not potentiate the effects of electrical stimulation on the evaluated parameters.

Inter-machine reliability of the Biodex and Cybex isokinetic dynamometers for knee flexor/extensor isometric, concentric and eccentric tests

OBJECTIVES

To assess the inter-machine reliability of the Biodex System 3 Pro and Cybex Humac Norm Model 770 dynamometers for knee extensor and knee flexor peak torque measurements in isometric, concentric and eccentric tests.

DESIGN

Randomized/crossover.

SETTING

Exercise Research Laboratory, Federal University of Rio Grande do Sul (Brazil).

PARTICIPANTS

25 healthy male subjects.

MAIN OUTCOME MEASURES

Isometric, concentric and eccentric knee extensor and knee flexor peak torques recorded in the same test procedure performed on both isokinetic dynamometers. One-way ANOVA, intraclass correlation coefficient (ICC), standard error of measurement (SEM) and coefficient of variation (CV) were used to verify significant differences, relative and absolute reliability between devices.

RESULTS

No significant differences were found between tests performed on Biodex and Cybex (p > 0.05). ICC values indicated a high to very high reproducibility for isometric, concentric and eccentric peak torques (0.88-0.92), and moderate to high reliability for agonist-antagonist strength ratios (0.62-0.73). Peak torque did not show great difference between dynamometers for SEM (3.72-11.27 Nm) and CV (5.27-7.77%). Strength ratios presented CV values of 8.57-10.72%.

CONCLUSION

Maximal knee extensor and knee flexor tests performed in isometric (60° of knee flexion), concentric and eccentric modes at 60°/s in Biodex and Cybex dynamometers present similar values.

Changes in contractile and elastic properties of the triceps surae muscle induced by neuromuscular electrical stimulation training

PURPOSE

Neuromuscular electrical stimulation (NMES) training is known to induce improvement in force production capacities and fibre-type transition. The aim of this study was to determine whether NMES training also leads to changes in the mechanical properties of the human triceps surae (TS) muscle.

METHODS

Fifteen young male subjects performed a training protocol (4 weeks, 18 sessions, 4-5 sessions per week) based on a high-frequency isometric NMES programme of TS muscle. Quick-release test was used to evaluate Musculo-Tendinous (MT) stiffness index (SIMT) as the slope of the linear MT stiffness-torque relationships under submaximal contraction. Sinusoidal perturbations allowed the assessment of musculo-articular stiffness index (SIMA) as well as the calculation of the maximal angular velocity ([Formula: see text]) of TS muscle using an adaptation of Hill's equation.

RESULTS

After NMES training, Maximal Voluntary Contraction under isometric conditions and [Formula: see text] increased significantly by 17.5 and 20.6 %, respectively, while SIMT and SIMA decreased significantly (-12.7 and -9.3 %, respectively).

CONCLUSIONS

These changes in contractile and elastic properties may lead to functional changes of particular interest in sport-related activities as well as in the elderly.

Cortical activation change induced by neuromuscular electrical stimulation during hand movements: a functional NIRS study

OBJECTIVES

Neuromuscular electrical stimulation (NMES) has been used in the field of rehabilitation for a long time. Previous studies on NMES have focused on the peripheral effect, in contrast, relatively little is known about the effect on the cerebral cortex. In the current study, we attempted to investigate the change of cortical activation pattern induced by NMES during execution of hand movements in normal subjects, using functional near infrared spectroscopy (fNIRS).

METHODS

Twelve healthy normal subjects were randomly assigned to the NMES group (six subjects) and the sham group (six subjects). We measured oxy-hemoglobin (HbO) in six regions of interest (ROI) during pre-NMES and post-NMES motor phase; the left dorsolateral and ventrolateral prefrontal cortex, premotor cortex, primary sensory-motor cortex (SM1), hand somatotopic area of SM1, and posterior parietal cortex. Between the pre-NMES and the post-NMES motor phases, real or sham NMES was applied on finger and wrist extensors of all subjects during a period of 5 minutes.

RESULTS

In all groups, during the pre-NMES motor phase, the HbO value in the hand somatotopic area of the left SM1 was higher than those of other ROIs. In the NMES group, during the post-NMES motor phase, HbO value variation in the hand somatotopic area of the left SM1 showed a significant decrease, compared with that of sham group (p < 0.05). However, in the sham group, similar aspect of results in HbO values of all ROIs was observed between pre-NMES and post-NMES motor phases (p > 0.05).

CONCLUSIONS

Results of this study showed that NMES induced a decrease of cortical activation during execution of hand movements. This finding appears to indicate that application of NMES can increase the efficiency of the cerebral cortex during execution of motor tasks.