Feasibility of a Novel Video Game-Based Electromyography Biofeedback System in Patients With Knee Osteoarthritis.

CONTEXT: A novel virtual game system Knee Biofeedback Rehabilitation Interface for game-based home therapy (KneeBright) was developed for strength training using integrated electromyography biofeedback of the quadriceps muscle to control the game. The study aimed to compare the KneeBright and electromyography biofeedback interface among patients with knee osteoarthritis. DESIGN: Controlled before and after design. METHODS: Nineteen patients with knee osteoarthritis took part in this laboratory-based study. Exercise sessions took place on 2 separate days. During session 1, participants used a conventional electromyography biofeedback system while performing 3 sets of lower body exercises with emphasis on maximal muscle activation, endurance, and precision. During session 2, participants used the KneeBright game to match the exercise sets in the first session. For both sessions, knee extension torque during the isometric muscle activation exercises and time to voluntary additional exercise were recorded. Patient engagement was assessed using the technology acceptance model and System Usability Score questionnaires. RESULTS: The peak knee extension torque produced during the control exercise session and the KneeBright exercise session were positively correlated. Knee extension torque generated during KneeBright game exercise sessions was increased by an average of 25% compared to the control sessions (2.14 vs 1.77 N·m/kg, P = .02). The mean technology acceptance model score for the KneeBright system was 3.4/5 and the mean System Usability Score was 79, both indicating positive patient engagement. CONCLUSIONS: Patients using the KneeBright game produced greater knee torque than patients using the conventional system, had positive levels of engagement, and exercised longer with the KneeBright game.

Clinical usage, application procedures, and perceived effectiveness of cupping therapy among healthcare professionals in the United States: A cross-sectional survey.

BACKGROUND: Despite its growing popularity since the mid-1900s, the application procedures and factors influencing the usage of cupping therapy among healthcare professionals in the United States remains unclear. Therefore, the purpose of this study was to investigate the clinical usage, application procedures, and perceived effectiveness of cupping therapy among healthcare professionals in the United States. MATERIALS AND METHODS: A convenience sample of 158 healthcare professionals (age: 29.36 ± 7.42 years) participated in this cross-sectional study (completion rate = 86.15%; n = 158/195). A custom web-based survey designed to assess respondents' clinical incorporation of cupping therapy, was disseminated through snowball sampling on various social media platforms. Descriptive statistics including means, standard deviations, and frequencies were calculated per survey item. RESULTS: Ninety-one percent of respondents reported working as an athletic trainer in either a secondary school (30%) or collegiate setting (48%). Dry cupping was the most commonly reported type of cupping therapy (99%), and 75% of respondents reported using both static and moving cupping techniques. Significant differences in cup application time and the amount of air extraction were noted between static and moving cupping. Cupping therapy was reported as most effective for treating muscle tightness, myofascial trigger points, and musculoskeletal pain. CONCLUSION: While the usage and application of cupping therapy may vary based on the type and style of cupping as well as the patient's condition, respondents reported cupping therapy to be an effective method for treating various musculoskeletal conditions.

Gait biofeedback and impairment-based rehabilitation for chronic ankle instability.

Our purpose was to analyze the effects of 4 weeks of visual gait biofeedback (GBF) and impairment-based rehabilitation on gait biomechanics and patient-reported outcomes (PROs) in individuals with chronic ankle instability (CAI). Twenty-seven individuals with CAI participated in this randomized controlled trial (14 received no biofeedback (NBF), 13 received GBF). Both groups received 8 sessions of impairment-based rehabilitation. The GBF group received visual biofeedback to reduce ankle frontal plane angle at initial contact (IC) during treadmill walking. The NBF group walked for equal time during rehabilitation but without biofeedback. Dependent variables included three-dimensional kinematics and kinetics at the ankle, knee, and hip, electromyography amplitudes of 4 lower extremity muscles (tibialis anterior, fibularis longus, medial gastrocnemius, and gluteus medius), and PROs (Foot and Ankle Ability Measure Activities of Daily Living (FAAM-ADL), FAAM-Sport, Tampa Scale of Kinesiophobia (TSK), and Global Rating of Change (GROC)). The GBF group significantly decreased ankle inversion at IC (MD:-7.3º, g = 1.6) and throughout the entire stride cycle (peak inversion: MD:-5.9º, g = 1.2). The NBF group did not have significantly altered gait biomechanics. The groups were significantly different after rehabilitation for the FAAM-ADL (GBF: 97.1 ± 2.3%, NBF: 92.0 ± 5.7%), TSK (GBF: 29.7 ± 3.7, NBF: 34.9 ± 5.8), and GROC (GBF: 5.5 ± 1.0, NBF:3.9 ± 2.0) with the GBF group showing greater improvements than the NBF group. There were no significant differences between groups for kinetics or electromyography measures. The GBF group successfully decreased ankle inversion angle and had greater improvements in PROs after intervention compared to the NBF group. Impairment-based rehabilitation combined with visual biofeedback during gait training is recommended for individuals with CAI.

Visual Biofeedback and Changes in Lower Extremity Kinematics in Individuals With Medial Knee Displacement.

CONTEXT: Increased frontal-plane knee motion during functional tasks, or medial knee displacement, is a predictor of noncontact anterior cruciate ligament injury and patellofemoral pain. Intervention studies that resulted in a reduced risk of knee injury included some form of feedback to address aberrant lower extremity movement patterns. Research on integrating feedback into single-legged tasks and the ability to train 1 task and test another is limited. OBJECTIVE: To determine if adding real-time visual biofeedback to common lower extremity exercises would improve single-legged landing mechanics in females with medial knee displacement. DESIGN: Cohort study. SETTING: University laboratory. PATIENTS OR OTHER PARTICIPANTS: Twenty-four recreationally active females with medial knee displacement were randomized to a visual-biofeedback group (n = 12; age = 19.75 ± 0.87 years, height = 165.32 ± 8.69 cm, mass = 62.41 ± 8.91 kg) or a control group (n = 12; age = 19.75 ± 0.97 years, height = 166.98 ± 6.89 cm, mass = 59.98 ± 6.24 kg). INTERVENTION(S): Individuals in the feedback group viewed a real-time digital model of their body segments generated by Microsoft Kinect. The skeletal model changed color according to the knee-abduction angle of the test limb during the exercise tasks. MAIN OUTCOME MEASURE(S): Participants completed 3 trials of the single-legged drop vertical jump (SL-DVJ) while triplanar kinematics at the trunk, hip, knee, and ankle were collected via 3-dimensional motion capture. The feedback and control groups completed lower extremity exercises with or without real-time visual biofeedback, respectively. After the intervention, participants completed 3 additional trials of the SL-DVJ. RESULTS: At baseline, the feedback group had 3.83° more ankle eversion than the control group after initial contact. After the intervention, the feedback group exhibited 13.03° more knee flexion during the flight phase of the SL-DVJ and 6.16° less knee abduction after initial contact than the control group. The feedback group also demonstrated a 3.02° decrease in peak knee-abduction excursion compared with the baseline values (P = .008). CONCLUSIONS: Real-time visual biofeedback immediately improved faulty lower extremity kinematics related to knee-injury risk. Individuals with medial knee displacement adjusted their movement patterns after a single training session and reduced their medial knee motion during a dynamic task.

Improvements in Lower-Extremity Function Following a Rehabilitation Program With Patterned Electrical Neuromuscular Stimulation in Females With Patellofemoral Pain: A Randomized Controlled Trial.

CONTEXT: Patellofemoral pain (PFP) is a challenging condition, with altered kinematics and muscle activity as 2 common impairments. Single applications of patterned electrical neuromuscular stimulation (PENS) have improved both kinematics and muscle activity in females with PFP; however, the use of PENS in conjunction with a rehabilitation program has not been evaluated. OBJECTIVE: To determine the effects of a 4-week rehabilitation program with PENS on lower-extremity biomechanics and electromyography (EMG) during a single-leg squat (SLS) and a step-down task (SDT) in individuals with PFP. STUDY DESIGN: Double-blinded randomized controlled trial. SETTING: Laboratory. Patients of Other Participants: Sixteen females with PFP (age 23.3 [4.9] y, mass 66.3 [13.5] kg, height 166.1 [5.9] cm). INTERVENTION: Patients completed a 4-week supervised rehabilitation program with or without PENS. MAIN OUTCOME MEASURES: Curve analyses for lower-extremity kinematics and EMG activity (gluteus maximus, gluteus medius, vastus medialis oblique, vastus lateralis, biceps femoris, and adductor longus) were constructed by plotting group means and 90% confidence intervals throughout 100% of each task, before and after the rehabilitation program. Mean differences (MDs) and SDs were calculated where statistical differences were identified. RESULTS: No differences at baseline in lower-extremity kinematics or EMG were found between groups. Following rehabilitation, the PENS group had significant reduction in hip adduction between 29% and 47% of the SLS (MD = 4.62° [3.85°]) and between 43% and 69% of the SDT (MD = 6.55° [0.77°]). Throughout the entire SDT, there was a decrease in trunk flexion in the PENS group (MD = 10.91° [1.73°]). A significant decrease in gluteus medius activity was seen during both the SLS (MD = 2.77 [3.58]) and SDT (MD = 4.36 [5.38]), and gluteus maximus during the SLS (MD = 1.49 [1.46]). No differences were seen in the Sham group lower-extremity kinematics for either task. CONCLUSION: Rehabilitation with PENS improved kinematics in both tasks and decreased EMG activity. This suggests that rehabilitation with PENS may improve muscle function during functional tasks.

Impairment-Based Rehabilitation With Patterned Electrical Neuromuscular Stimulation and Lower Extremity Function in Individuals With Patellofemoral Pain: A Preliminary Study.

CONTEXT: Patellofemoral pain (PFP) is a chronic condition that presents with lower extremity muscle weakness, decreased flexibility, subjective functional limitations, pain, and decreased physical activity. Patterned electrical neuromuscular stimulation (PENS) has been shown to affect muscle activation and pain after a single treatment, but its use has not been studied in a rehabilitation trial. OBJECTIVE: To determine the effects of a 4-week impairment-based rehabilitation program using PENS on subjective function, pain, strength, range of motion, and physical activity in individuals with PFP. DESIGN: Randomized controlled trial. SETTING: Laboratory. PATIENTS OR OTHER PARTICIPANTS: A total of 21 patients with PFP (5 males, 16 females; age = 23.4 ± 7.6 years, height = 168.0 ± 7.5 cm, mass = 69.0 ± 19.5 kg). INTERVENTION(S): Participants completed a 4-week supervised rehabilitation program in conjunction with random assignment to receive PENS or sham treatments. MAIN OUTCOME MEASURE(S): Subjective function, pain, strength, range of motion, and physical activity levels were assessed prerehabilitation and postrehabilitation. Subjective function and pain were also assessed at 6 and 12 months postrehabilitation. Repeated-measures analyses of variance and Tukey post hoc testing were conducted with α ≤ .05. We calculated Cohen d effect sizes with 95% confidence intervals. RESULTS: Both groups had statistically and clinically meaningful differences in subjective function, pain, strength, range of motion, and activity level after 4 weeks of impairment-based rehabilitation. Improved subjective function was observed in both groups at 6 and 12 months after the interventions. The PENS group had improvements in current pain for all 3 postrehabilitation times compared with baseline measures. CONCLUSIONS: An impairment-based intervention effectively improved subjective function, pain, strength, range of motion, and physical activity levels in individuals with PFP. Participants who received PENS in addition to the rehabilitation program had improved current pain at 6 and 12 months postrehabilitation compared with baseline scores. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02441712.

Reliability of a novel approach for quadriceps motor point assessment.

INTRODUCTION: We studied the ability of clinicians to identify quadriceps motor points using a transcutaneous electrical stimulation unit (TENS). METHODS: Twenty-two certified athletic trainers and 1 expert-rater identified the 7 motor points of the quadriceps at 2 time-points separated by 1 week. The difference was calculated between where each participant and the expert-rater identified each motor point using an x-y coordinate system. Bland-Altman plots were used to compare differences between 2 testing sessions. RESULTS: No differences were observed between participants and the expert-rater for motor point location. The smallest variability in the limits of agreements were observed in the distal vastus medialis oblique (-1.89 to 1.86 cm) and proximal vastus lateralis (-1.61 to 2.35 cm). DISCUSSION: Our results suggest the utilization of a TENS unit may be 1 way to identify quadriceps motor points to improve electrical stimulation applications. The smallest limits of agreement were over the most common quadriceps electrical stimulation electrode positions. Muscle Nerve 57: E1-E7, 2018.

Immediate Effect of Patterned Electrical Neuromuscular Stimulation on Pain and Muscle Activation in Individuals With Patellofemoral Pain.

CONTEXT: For individuals with patellofemoral pain (PFP), altered muscle activity and pain are common during functional tasks. Clinicians often seek interventions to improve muscle activity and reduce impairments. One intervention that has not been examined in great detail is electrical stimulation. OBJECTIVE: To determine whether a single patterned electrical neuromuscular stimulation (PENS) treatment would alter muscle activity and pain in individuals with PFP during 2 functional tasks, a single-legged squat and a lateral step down. DESIGN: Cohort study. SETTING: Sports medicine research laboratory. PATIENTS OF OTHER PARTICIPANTS: A total of 22 individuals with PFP (15 women, 7 men; age = 26.0 ± 7.9 years, height = 173.8 ± 8.1 cm, mass = 75.1 ± 17.9 kg). INTERVENTION(S): Participants were randomized into 2 intervention groups: a 15-minute PENS treatment that produced a strong motor response or a 15-minute 1-mA subsensory (sham) treatment. MAIN OUTCOME MEASURE(S): Before and immediately after the intervention, we assessed normalized electromyography amplitude, percentage of activation time across functional tasks, and onset of activation for the vastus medialis oblique, vastus lateralis, gluteus medius, adductor longus, biceps femoris, and medial gastrocnemius muscles during a single-legged squat and a lateral step down. Scores on the visual analog scale for pain were recorded before and after the intervention. RESULTS: After a single treatment of PENS, the percentage of gluteus medius activation increased (0.024) during the lateral step down. Visual analog scores decreased during both the single-legged squat (PENS: preintervention = 2.7 ± 1.9, postintervention = 0.9 ± 0.7; sham: preintervention = 3.2 ± 1.6, postintervention = 2.8 ± 1.9; group × time interaction: P = .041) and lateral step down (PENS: preintervention = 3.4 ± 2.4, postintervention = 1.1 ± 0.8; sham: preintervention = 3.9 ± 1.7, postintervention = 3.3 ± 2.0; group × time interaction: P = .023). No changes in electromyography or pain measures were noted in the sham group. CONCLUSIONS: The PFP participants who received PENS had immediate improvement in gluteus medius activation and a reduction in pain during functional tasks.

Improvements in kinematics, muscle activity and pain during functional tasks in females with patellofemoral pain following a single patterned electrical stimulation treatment.

BACKGROUND: Individuals with patellofemoral pain present with altered hip muscle activation, faulty movement patterns, and pain during functional tasks. Examining new treatment options to address these impairments may better treat those with patellofemoral pain. The purpose of this study was to determine if patterned electrical stimulation to the lower extremity affects muscle activity, movement patterns, and pain following a single treatment. METHODS: Fifteen females with patellofemoral pain were randomized to receive a single 15-minute treatment of either a patterned electrical neuromuscular stimulation or a sham. Peak kinematics of the knee, hip, and trunk, electromyography and pain were examined pre and post-intervention during a single leg squat and lateral step-down task. Group means and pre/post reduced kinematic values were also plotted during the entire task with 90% confidence intervals to identify differences in movement strategies. FINDINGS: No baseline differences were found in peak kinematics between groups. No pre to post-intervention differences in peak knee, hip and trunk kinematics were found, however differences were seen when the quality of movement across the entire tasks was assessed. The electrical stimulation group had improved knee flexion and hip abduction during the lateral step-down. A significant improvement in gluteus medius activation following patterned electrical neuromuscular stimulation occurred during the step-down (P=0.039). Significant pain improvements were also seen in both the single leg squat (P=0.025) and lateral step-down (P=0.006). INTERPRETATION: A single treatment of patterned electrical neuromuscular stimulation improved muscle activation, lower extremity kinematics during functional tasks, and pain.

Can the Use of Neuromuscular Electrical Stimulation Be Improved to Optimize Quadriceps Strengthening?

CONTEXT: Neuromuscular electrical stimulation (NMES) is a common modality used to retrain muscles and improve muscular strength after injury or surgery, particularly for the quadriceps muscle. There are parameter adjustments that can be made to maximize the effectiveness of NMES. While NMES is often used in clinical practice, there are some limitations that clinicians should be aware of, including patient discomfort, muscle fatigue, and muscle damage. EVIDENCE ACQUISITION: PubMed was searched through August 2014 and all articles cross-referenced. STUDY DESIGN: Clinical review. LEVEL OF EVIDENCE: Level 3. RESULTS: Clinicians can optimize torque production and decrease discomfort by altering parameter selection (pulse duration, pulse frequency, duty cycle, and amplitude). Pulse duration of 400 to 600 µs and a pulse frequency of 30 to 50 Hz appear to be the most effective parameters to optimize torque output while minimizing discomfort, muscle fatigue, or muscle damage. Optimal electrode placement, conditioning programs, and stimulus pattern modulation during long-term NMES use may improve results. CONCLUSION: Torque production can be enhanced while decreasing patient discomfort and minimizing fatigue.

Changes in muscle thickness after exercise and biofeedback in people with low back pain.

CONTEXT: Individuals with low back pain (LBP) have reduced function of the transversus abdominis (TrA) and lumbar multifidus (LM) muscles. Biofeedback during exercise may increase the ability to contract the TrA and LM muscles compared with exercise alone. OBJECTIVE: To compare TrA preferential activation ratio (PAR) and the percent change in LM-muscle thickness in patients with LBP history before and after exercise with or without biofeedback. DESIGN: Controlled laboratory study. SETTING: University research laboratory. PATIENTS: 20 LBP individuals, 10 exercise alone and 10 exercise with biofeedback. INTERVENTIONS: Patients were allotted to tabletop exercises in isolation or tabletop exercises with visual, auditory, and tactile biofeedback. MAIN OUTCOME MEASURES: TrA PAR and percent change in LM-muscle thickness. RESULTS: There were no differences between groups at baseline (all P > .05). Nonparametric statistics showed decreased resting muscle thickness for total lateral abdominal-wall muscles (P = .007) but not TrA (P = .410) or LM (P = .173). Percent TrA thickness increased from table to standing positions before (P = .006) and after exercise (P = .009). TrA PAR increased after exercise (pre 0.01 ± 0.02, post 0.03 ± 0.04, P = .033) for all patients and for exercise with biofeedback (pre 0.02 ± 0.01, post 0.03 ± 0.01, P = .037) but not for exercise alone (pre 0.01 ± 0.02, post 0.02 ± 0.05, P = .241). No group differences were observed for TrA PAR before (exercise 0.01 ± 0.02, exercise with biofeedback 0.02 ± 0.01, P = .290) or after exercise (exercise 0.02 ± 0.05, exercise with biofeedback 0.03 ± 0.01, P = .174). There were no group differences in LM percent change before exercise (P = .999) or after exercise (P = .597). In addition, no changes were observed in LM percent change as a result of exercise among all participants (P = .391) or for each group (exercise P = .508, exercise with biofeedback P = .575). CONCLUSION: TrA PAR increased after a single session of exercises, whereas no thickness changes occurred in LM.

Lack of effect of superficial heat to the knee on quadriceps function in individuals with quadriceps inhibition.

CONTEXT: Quadriceps function improves after application of focal joint cooling or transcutaneous electrical nerve stimulation to the knee in patients with arthrogenic muscle inhibition (AMI), yet it is not known whether superficial heat is able to produce a similar effect. OBJECTIVE: To determine quadriceps function after superficial heat to the knee joint in individuals with AMI. DESIGN: Single blinded randomized crossover. SETTING: Laboratory. PATIENTS: 12 subjects (4 female, 8 males; 25.6 ± 7.7 y, 177.2 ± 12.7 cm, 78.4 ± 18.2 kg) with a history of knee-joint pathology and AMI, determined with a quadriceps central activation ratio (CAR) of <90%. INTERVENTION: 3 treatment conditions for 15 min on separate days: superficial heat using a cervical moist-heat pack (77 °C), sham using a cervical moist pack (room temperature at about 24 °C), and control (no treatment). All subjects received all treatment conditions in a randomized order. MAIN OUTCOME MEASURES: Central activation ratio and knee-extension torque during maximal voluntary isometric contraction with the knee flexed to 60° were collected at pre, immediately post, 30 min post, and 45 min posttreatment. Skin temperature of the quadriceps and knee and room temperature were also recorded at the same time points. RESULTS: Three (treatment conditions) by 4 (time) repeated ANOVAs found that there were no significant interactions or main effects in either CAR or knee-extension torque (all P > .05). Skin-temperature 1-way ANOVAs revealed that the skin temperature in the knee during superficial heat was significantly higher than other treatment conditions at all time points (P < .05). CONCLUSIONS: Superficial heat to the knee joint using a cervical moist-heat pack did not influence quadriceps function in individuals with AMI in the quadriceps.

Relative acoustic transmission of topical preparations used with therapeutic ultrasound.

OBJECTIVE: To determine the relative acoustic transmission allowed by various preparations at 1MHz and 3MHz ultrasound (US) frequencies. DESIGN: Bench-top laboratory study. SETTING: Laboratory. PARTICIPANTS: No human or animal participants were used. INTERVENTIONS: We administered continuous US through various over-the-counter preparations at 1.2W/cm(2) at both 1MHz and 3MHz frequencies for 30 seconds and measured the acoustic output. MAIN OUTCOME MEASURES: Percentage of transmission of energy relative to commercial US gel. Planned observational comparisons were made at both 1MHz and 3MHz frequencies. Topical agents were categorized as either gel-based or cream-based preparations. RESULTS: Transmission of gel-based preparations (1MHz and 3MHz): Arnica gel (97% and 110%), Biofreeze (60% and 79%), Capzasin (70% and 93%), Cobroxin (76% and 91%), and Solarcaine (70% and 101%). Cream-based preparations (1MHz and 3MHz): Arnica cream (67% and 74%), Australian Dream (54% and 80%), Bengay (37% and 55%), MediPeds Footcare (126% and 101%), Neuragen PN (76% and 90%), Octogen (38% and 47%), and Thera-Gesic (52% and 73%). CONCLUSIONS: Topical agents suspended in aqueous gels are generally more effective in transmitting US energy, while many cream-based agents are less effective, particularly at 1MHz frequency. Many agents that are commonly used to provide a sensory effect, such as topical analgesic creams, may block US transmission. Agents that reduce US transmission may lead to poor phonophoresis results and are likely to minimize the therapeutic effects of US.

Clinimetric analysis of pressure biofeedback and transversus abdominis function in individuals with stabilization classification low back pain.

STUDY DESIGN: Descriptive laboratory study. OBJECTIVE: To determine if a proposed clinical test (pressure biofeedback) could detect changes in transversus abdominis (TrA) muscle thickness during an abdominal drawing-in maneuver. BACKGROUND: Pressure biofeedback may be used to assess abdominal muscle function and TrA activation during an abdominal drawing-in maneuver but has not been validated. METHODS: Forty-nine individuals (18 men, 31 women) with low back pain who met stabilization classification criteria underwent ultrasound imaging to quantify changes in TrA muscle thickness while a pressure transducer was used to measure pelvic and spine position during an abdominal drawing-in maneuver. A paired t test was used to compare differences in TrA activation ratios between groups (able or unable to maintain pressure of 40 ± 5 mmHg). The groups were further dichotomized based on TrA activation ratio (high, greater than 1.5; low, less than 1.5). Sensitivity, specificity, and likelihood ratios were calculated. RESULTS: There was not a significant difference (P = .57) in TrA activation ratios (able to maintain pressure, 1.59 ± 0.28; unable to maintain pressure, 1.54 ± 0.24) between groups. The pressure biofeedback test had low sensitivity of 0.22 (95% confidence interval [CI]: 0.10, 0.42) but moderate specificity of 0.77 (95% CI: 0.58, 0.89), a positive likelihood ratio of 0.94 (95% CI: 0.33, 2.68), and a negative likelihood ratio of 1.02 (95% CI: 0.75, 1.38). CONCLUSION: Successful completion on pressure biofeedback does not indicate high TrA activation. Unsuccessful completion on pressure biofeedback may be more indicative of low TrA activation, but the correlation and likelihood coefficients indicate that the pressure test is likely of minimal value to detect TrA activation. This study was registered with ClinicalTrials.gov (NCT01015846).J Orthop Sports Phys Ther 2013;43(3):184-193. Epub 16 November 2012. doi:10.2519/jospt.2013.4397.

Changes in voluntary quadriceps activation predict changes in quadriceps strength after therapeutic exercise in patients with knee osteoarthritis.

INTRODUCTION: Recent rehabilitation paradigms have suggested that improving voluntary muscle activation may optimize strength outcomes related to resistance training. The aim of this study was to determine if changes in voluntary quadriceps activation could predict changes in quadriceps strength following a 4 week therapeutic exercise regimen. METHOD: Thirty-six participants with tibiofemoral osteoarthritis volunteered for this study, while 30 participants (14 males, 16 females, 58 ± 11.8 years, 172.2 ± 9.2 cm, 87.1 ± 18.5 kg) finished the 4 week supervised therapeutic exercise protocol and were used in the final analysis. Demographics, quadriceps strength and voluntary quadriceps activation using the burst superimposition technique were evaluated prior to the intervention. Following the therapeutic exercise program, quadriceps strength and voluntary activation were assessed. Simple correlations were performed to determine covariates in a multiple regression equation to evaluate if changes in voluntary quadriceps activation could predict changes in quadriceps strength. RESULTS: There was a significant moderate simple correlation between participant height and change in MVIC (r=-0.44, P=0.01). Both height and changes in voluntary quadriceps activation significantly predicted changes in MVIC (R(2)=0.66, P<0.001). After controlling for patient height, a change in voluntary quadriceps activation produced a significant improvement in the prediction of a change in MVIC (ΔR(2)=0.47, P<0.001). DISCUSSION: Changes in voluntary quadriceps activation predicted 47% of variance in the change in quadriceps strength. These results suggest that interventions aimed at manipulating quadriceps activation may be helpful for improving quadriceps strength in patients with tibiofemoral osteoarthritis.

Effects of transcutaneous electrical nerve stimulation and therapeutic exercise on quadriceps activation in people with tibiofemoral osteoarthritis.

STUDY DESIGN: Blinded, randomized controlled trial. OBJECTIVES: To determine if the combination of transcutaneous electrical nerve stimulation (TENS) set to a sensory level and therapeutic exercise would be more effective than the combination of placebo TENS and therapeutic exercises or therapeutic exercises only to increase quadriceps activation in individuals with tibiofemoral osteoarthritis. BACKGROUND: Quadriceps activation deficits are common in those with tibiofemoral osteoarthritis, and TENS has been reported to immediately increase quadriceps activation. Yet the long-term benefits of TENS for motor neuron activation have yet to be determined. METHODS: Thirty-six individuals with radiographically assessed tibiofemoral osteoarthritis were randomly assigned to the TENS and exercise, placebo and exercise, and exercise only groups. All participants completed a supervised 4-week lower extremity exercise program. TENS and placebo TENS were worn throughout the therapeutic exercise sessions, as well as during daily activities. Our primary outcome measures, quadriceps central activation ratio, and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were evaluated at baseline and at 2 weeks and 4 weeks of the intervention. RESULTS: Quadriceps activation was significantly higher in the TENS with exercise group compared to the exercise only group at 2 weeks (0.94 ± 0.04 versus 0.82 ± 0.12, P<.05) and the placebo and exercise group at 4 weeks (0.94 ± 0.06 versus 0.81 ± 0.15, P<.05). WOMAC scores improved in all 3 groups over time, with no significant differences among groups. CONCLUSION: This study provides evidence that TENS applied in conjunction with therapeutic exercise and daily activities increases quadriceps activation in patients with tibiofemoral osteoarthritis and, while function improved for all participants, effects were greatest in the group treated with a combination of TENS and therapeutic exercises. LEVEL OF EVIDENCE: Therapy, level 1b-.

Effects of disinhibitory transcutaneous electrical nerve stimulation and therapeutic exercise on sagittal plane peak knee kinematics and kinetics in people with knee osteoarthritis during gait: a randomized controlled trial.

OBJECTIVE: to determine whether sensory transcutaneous electrical nerve stimulation (TENS) augmented with therapeutic exercise and worn for daily activities for four weeks would alter peak gait kinetics and kinematics, compared with placebo electrical stimulation and exercise, and exercise only. DESIGN: randomized controlled trial. SETTING: motion analysis laboratory. SUBJECTS: thirty-six participants with radiographically assessed knee osteoarthritis and volitional quadriceps activation below 90% were randomly assigned to electrical stimulation, placebo and comparison (exercise-only) groups. INTERVENTIONS: participants in all three groups completed a four-week quadriceps strengthening programme directed by an experienced rehabilitation clinician. Active electrical stimulation units and placebo units were worn in the electrical stimulation and placebo groups throughout the rehabilitation sessions as well as during all activities of daily living. MAIN MEASURES: peak external knee flexion moment and angle during stance phase were analysed at a comfortable walking speed before and after the intervention. FINDINGS: Comfortable walking speed increased for all groups over time (TENS 1.16 ± 0.15 versus 1.32 ± 0.16 m/s; placebo 1.21 ± 0.34 versus 1.3 ± 0.24 m/s; comparison 1.27 ± 0.18 versus 1.5 ± 0.14 m/s), yet no group differences in speed were found. No differences were found for peak flexion moment or angle between groups overtime. CONCLUSIONS: TENS in conjunction with therapeutic exercise does not seem to affect peak flexion moment and angle during stance over a four-week period in participants with tibiofemoral osteoarthritis.

Effects of neuromuscular electrical stimulation after anterior cruciate ligament reconstruction on quadriceps strength, function, and patient-oriented outcomes: a systematic review.

STUDY DESIGN: Systematic literature review. OBJECTIVE: To perform a systematic review of randomized controlled trials assessing the effects of neuromuscular electrical stimulation (NMES) on quadriceps strength, functional performance, and self-reported function after anterior cruciate ligament reconstruction. BACKGROUND: Conflicting evidence exists regarding the effectiveness of NMES following anterior cruciate ligament reconstruction. METHODS: Searches were performed for randomized controlled trials using electronic databases from 1966 through October 2008. Methodological quality was assessed using the Physiotherapy Evidence Database Scale. Between-group effect sizes and 95% confidence intervals (CIs) were calculated. RESULTS: Eight randomized controlled trials were included. The average Physiotherapy Evidence Database Scale score was 4 out of possible maximum 10. The effect sizes for quadriceps strength measures (isometric or isokinetic torque) from 7 studies ranged from -0.74 to 3.81 at approximately 6 weeks postoperatively; 6 of 11 comparisons were statistically significant, with strength benefits favoring NMES treatment. The effect sizes for functional performance measures from 1 study ranged from 0.07 to 0.64 at 6 weeks postoperatively; none of 3 comparisons were statistically significant, and the effect sizes for self-reported function measures from 1 study were 0.66 and 0.72 at 12 to 16 weeks postoperatively; both comparisons were statistically significant, with benefits favoring NMES treatment. CONCLUSION: NMES combined with exercise may be more effective in improving quadriceps strength than exercise alone, whereas its effect on functional performance and patient-oriented outcomes is inconclusive. Inconsistencies were noted in the NMES parameters and application of NMES. LEVEL OF EVIDENCE: Therapy, level 1a-.

Immediate effects of transcutaneous electrical nerve stimulation and focal knee joint cooling on quadriceps activation.

PURPOSE: To determine whether transcutaneous electrical nerve stimulation (TENS) and focal knee joint cooling will affect the quadriceps central activation ratio (CAR) in patients with tibiofemoral osteoarthritis. METHODS: Thirty-three participants with diagnosed tibiofemoral osteoarthritis were randomly allocated to the 45-min TENS treatment (six males and four females, 56 +/- 10.1 yr, 174.11 +/- 10.78 cm, 89.34 +/- 21.3 kg), the 20-min focal knee joint cooling treatment (six males and five females, 58 +/- 8.4 yr, 176.41 +/- 8.29 cm, 83.18 +/- 17.97 kg), or the control group (five males and seven females, 54 +/- 9.9 yr, 166.37 +/- 13.07 cm, 92.14 +/- 25.37 kg). Volitional quadriceps activation, maximal voluntary isometric contraction, and subjective pain measurements were conducted at baseline and at 20, 30, and 45 min. The 20-min focal knee joint cooling intervention consisted of two 1.5-L ice bags to the anterior and posterior aspects of the knee. The TENS group received 45 min of a sensory, biphasic square wave stimulation (150-mus phase duration and 150 pps) from four 2 x 2-inch electrodes positioned around the patella. RESULTS: : TENS resulted in a significantly higher percent change in CAR scores compared with control at 20 min (6.4 +/- 4.8 vs -3.5 +/- 8, P = 0.006), 30 min (9.7 +/- 10.16 vs -1 +/- 7.9, P = 0.025), and 45 min (11.25 +/- 6.96 vs 0.81 +/- 9.4, P = 0.029). Focal knee joint cooling resulted in significantly higher percent change scores compared with the control group at 20 min (5.75 +/- 7.25 vs -3.5 +/- 8, P = 0.009) and trended to be higher at 45 min (9.06 +/- 9.63 vs 0.81 +/- 9.4, P = 0.098). No significant differences in percent change for CAR were found between the TENS and the focal knee joint cooling group. CONCLUSIONS: Both TENS and focal knee joint cooling increased the quadriceps CAR immediately after application in participants with tibiofemoral osteoarthritis.

Use of a combination of ankle pressure and SENSERite system to treat older adults with impaired ankle proprioception: a single-blind experimental study.

OBJECTIVE: To investigate the effects of a combination of visual biofeedback and ankle pressure on ankle position sense in elderly adults with and without impaired ankle joint position sense (JPS). DESIGN: Independent 2 x 3 factorial design with an experimenter-blind study. SETTING: University motion laboratory. PARTICIPANTS: Older adults (N=40) were recruited from local community centers. Among them, 21 elderly subjects had relatively normative score, whereas 19 subjects had impaired ankle position sense. INTERVENTION: Both the normative and impaired elderly subjects underwent either ankle JPS visual feedback training alone or a combination of ankle JPS visual feedback training and circumferential ankle pressure for one 30-minute training session. MAIN OUTCOME MEASURES: The outcome measures included ankle JPS errors measured in absolute constant error (ACE) and variable error (VE) during standing at pretest, posttest, and 1-week follow-up test. A separate repeated measures analyses of variance was performed to evaluate the differential training effects on ACE and VE, respectively. The Pearson chi-square test and Bonferroni test were performed. Significance was assigned at P less than .05 for all analyses. RESULTS: Regardless of intervention conditions, older adults with and without ankle position sense impairment showed immediate treatment benefits, which relatively remained stable even at the follow-up test. These effects were reflected in significant improvements of JPS accuracy and consistency (P<.05). CONCLUSIONS: Our findings may suggest that both interventions were equally effective in increasing ankle JPS accuracy and consistency in older adults with and without impairments, and therapeutic effects lasted for a week, reflecting long-term effect.