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.

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.

The value of the modern vascular surgeon to the health care system: A report from the Society for Vascular Surgery Valuation Work Group.

Vascular surgeons provide an important service to the health care system. They are capable of treating a wide range of disease processes that affect both the venous and arterial systems. Their presence broadens the complexity and diversity of services that a health care system can offer both in the outpatient setting and in the inpatient setting. Because of their ability to control hemorrhage, they are critical to a safe operating room environment. The vascular surgery service line has a positive impact on hospital margin through both the direct vascular profit and loss and the indirect result of assisting other surgical and medical services in providing care. The financial benefits of a vascular service line will hold true for a wide range of alternative payment models, such as bundled payments or capitation. To fully leverage a modern vascular surgeon's skill set, significant investment is required from the health care system that is, however, associated with substantial return on the investment.

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.

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.

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.

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.

Quadriceps function in anterior cruciate ligament-deficient knees exercising with transcutaneous electrical nerve stimulation and cryotherapy: a randomized controlled study.

OBJECTIVE: To compare strength and quadriceps muscle activation in anterior cruciate ligament-deficient patients who underwent a two-week rehabilitation exercise program using TENS or cryotherapy. DESIGN: Randomized, controlled study. SETTING: Clinical research laboratory. SUBJECTS: Thirty patients: 20 males, 10 females, 31.6 (13.0) years, 172.8 (10.0) cm, 75.8 (13.0) kg with diagnosed tear of the anterior cruciate ligament. INTERVENTIONS: All patients attended four sessions of supervised quadriceps strengthening exercises over two weeks, prior to reconstruction surgery. Patients were randomly allocated (n = 10/group) to receive exercises alone, exercise while wearing a sensory transcutaneous electrical nerve stimulation (TENS) device on the knee joint for the duration of each daily session, or 20 minutes of knee joint cryotherapy immediately prior to each daily exercise session. MAIN MEASURES: Normalized knee extension force and quadriceps central activation ratio were measured before and after the first supervised treatment session and within 24 hours of the last session. RESULTS: When accounting for differences in baseline measures, there were no statistically significant group differences immediately following the first exercise session for knee extension force (P = 0.10) or central activation ratio (P = 0.30) nor were there statistically significant group differences after the two-week intervention for knee extension force (P = 0.92) or central activation ratio (P = 0.94). Effect sizes for the change in knee extension force and central activation ratio after two weeks of therapy were all large. CONCLUSIONS: Quadriceps strength and central activation in anterior cruciate ligament deficient patients improved after two weeks of rehabilitaiton exercises, however, there were no significant differences between treatment groups.

Changes in lateral abdominal muscle thickness during an abdominal drawing-in maneuver in individuals with and without low back pain.

The purpose of this study was to compare lateral abdominal muscle thickness changes in individuals with and without low back pain (LBP) during an abdominal drawing-in maneuver (ADIM) using ultrasound imaging. Twenty individuals (13 females and 7 males, average age 40.1 ± 13.4) with stabilization classification LBP and 19 controls (10 females and 9 males, average age 30.3 ± 8.7) participated in this study. Bilateral measurements were made using ultrasound imaging to determine changes in thickness of the transversus abdominus (TrA) and external and internal oblique (EO+IO) muscles during an ADIM. There were no significant differences in relaxed muscle thickness values or contraction ratios for the TrA or EO+IO between groups or side. Individuals with stabilization classification LBP demonstrated no difference in lateral abdominal muscle thickness during an ADIM when compared with controls without LBP when using a pressure biofeedback device to monitor stability.

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-.

Quadriceps muscle activation and radiographic osteoarthritis following ACL revision.

PURPOSE: Quadriceps strength and activation may play an important role in the recovery from ACL revision surgery. The purpose of this study was to describe quadriceps strength and central activation ratio (CAR) and correlate with radiographic findings in patients with ACL revision surgery. METHODS: Twenty-one patients who were on average 47.5 ± 21.1 months [range: 14-85 months] post-revision ACL reconstruction. We performed knee joint physical examination and radiographic evaluation. Quadriceps strength testing consisted of maximal voluntary isometric contractions (MVIC) with the knee bent to 90-degrees bilaterally. We calculated quadriceps central activation ratio using the superimposed burst technique. Radiographs (bilateral standing antero-posterior in knee flexion and lateral in full extension) were evaluated by a fellowship-trained orthopedic surgeon using the International Knee Documentation Committee (IKDC) grading system. RESULTS: Mean CAR was 83.9 ± 12.0% on the reconstructed limb and 85.5 ± 9.5% on the contralateral limb. Average, normalized MVIC torque was 2.5 ± 1.0 Nm/kg on the reconstructed limb and 2.7 ± 1.0 N m/kg for the contralateral limb. Patient age at the time of follow-up evaluation was related to severity of knee joint degeneration, particularly the medial, anterior and patellofemoral compartments. Younger patients with lower CARs tended to have more severe degeneration in the patellofemoral joint. Older patients with lower normalized MVIC torque values tended to exhibit more severely graded degeneration in the patellofemoral joint. CONCLUSION: Bilateral quadriceps central activation deficits and radiographic osteoarthritis are evident in patients with revision ACL reconstruction.

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.

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.