The Effect of Diacutaneous Fibrolysis on Local and Widespread Hyperalgesia and Muscle Length in Patients With Patellofemoral Pain Syndrome: Secondary Analysis of a Pretest-Posttest Clinical Trial.

CONTEXT: Localized and widespread hyperalgesia has been observed in patients with patellofemoral pain. Diacutaneous fibrolysis (DF) has shown to be effective in reducing pain in several musculoskeletal conditions including patellofemoral pain syndrome, but no studies have evaluated the effects of this technique in reducing localized and widespread hyperalgesia. OBJECTIVE: To assess the effect of DF on the pressure pain threshold and muscle length tests in patients with patellofemoral pain syndrome. DESIGN: A single-group, pretest-posttest clinical trial. SETTING: University of Zaragoza. PARTICIPANTS: Forty-six subjects with patellofemoral pain (20 males and 26 females: age 27.8 [6.9] y). INTERVENTION: Three sessions of DF. MAIN OUTCOME MEASURES: Pressure pain threshold using a handheld pressure algometer (4 sites around the knee, on tibialis anterior muscle, and one remote site on the upper contralateral limb); muscle length test of the iliotibial band, rectus femoris, and hamstring muscles; and patient-perceived treatment effect score. RESULTS: The application of 3 sessions of DF significantly increased the pressure pain threshold in all sites at posttreatment evaluation (P < .001) and at a 1-week follow-up (P < .001). A significant increase in muscle length was also observed at the posttreatment evaluation (P < .001) and 1-week follow-up (P < .001). Ninety-seven percent of the patients reported subjective improvement at posttreatment and at 1-week follow-up. CONCLUSION: This study found that local and widespread hyperalgesia was significantly reduced after 3 sessions of diacutaneous fibrolysis and at the 1-week follow-up. A significant improvement on muscle length tests was also observed, with high clinical satisfaction among patients.

A Contemporary Approach to Patellofemoral Pain in Runners.

Patellofemoral pain (PFP) is among the most common injuries in recreational runners. Current evidence does not identify alignment, muscle weakness, and patellar maltracking or a combination of these as causes of PFP. Rather than solely investigating biomechanics, we suggest a holistic approach to address the causes of PFP. Both external loads, such as changes in training parameters and biomechanics, and internal loads, such as sleep and psychological stress, should be considered. As for the management of runners with PFP, recent research suggested that various interventions can be considered to help symptoms, even if these interventions target biomechanical factors that may not have caused the injury in the first place. In this Current Concepts article, we describe how the latest evidence on education about training modifications, strengthening exercises, gait and footwear modifications, and psychosocial factors can be applied when treating runners with PFP. The importance of maintaining relative homeostasis between load and capacity will be emphasized. Recommendations for temporary or longer-term interventions will be discussed. A holistic, evidence-based approach should consist of a graded exposure to load, including movement, exercise, and running, while considering the capacity of the individual, including sleep and psychosocial factors. Cost, accessibility, and the personal preferences of patients should also be considered.

Prevalence and sensitivity of trigger points in lumbo-pelvic-hip muscles in patients with patellofemoral pain syndrome.

OBJECTIVES: Changes in the activity of the lumbo-pelvic-hip muscles have been established as a major cause of patellofemoral pain syndrome (PFPS), a common orthopedic problem. The present study aimed to compare the prevalence and sensitivity of myofascial trigger points (MTrPs) in lumbo-pelvic-hip muscles in persons with and without PFPS. METHODS: Thirty women with PFPS and 30 healthy women 18-40 years old were recruited for this study. The prevalence of MTrPs was assessed by palpation, and pressure algometry was used to measure the pressure pain threshold. This study evaluated the areas where MTrPs are most commonly found in the lumbar muscles (internal oblique, erector spinae and quadratus lumborum), pelvic muscles (gluteus maximus, gluteus medius, gluteus minimus and piriformis), and hip muscles (hip adductor, quadriceps, hamstring, tensor fascia lata and sartorius). Independent t-tests were used to compare mean pressure pain thresholds between the two groups. Chi-squared tests were used to compare the prevalence of MTrPs. RESULTS: The prevalence of MTrPs was significantly higher in most of the lumbo-pelvic-hip muscles in patients with PFPS compared to healthy persons. However, there were no significant differences between groups in the prevalence of MTrPs in the gluteus minimus or adductor muscles. The pressure pain threshold in lumbo-pelvic-hip muscles was lower in patients with PFPS compared to healthy participants. CONCLUSION: In patients with PFPS the prevalence of MTrPs in the lumbo-pelvic-hip region was higher, and the pressure pain threshold was lower, than in healthy people. Thus therapy to treat PFPS should target the lumbo-pelvic-hip muscles.

Simultaneous ice and transcutaneous electrical nerve stimulation decrease anterior knee pain during running but do not affect running kinematics or associated muscle inhibition.

BACKGROUND: Runners often experience anterior knee pain and this pain is associated with altered running neuromechanics. The purpose of this study was to examine potential therapeutic benefits (reduced pain and restored running neuromechanics) of simultaneously applied ice and transcutaneous electrical nerve stimulation on experimentally-induced anterior knee pain. METHODS: Nineteen healthy subjects completed a sham and treatment data collection session. For both sessions, hypertonic saline was infused into the infrapatellar fat pad for approximately 80 min to induce experimental anterior knee pain. Perceived pain levels were measured every two minutes and running neuromechanics were recorded at four time points: pre-pain, pain before treatment, pain immediately post-treatment, and pain 20 min post-treatment. FINDINGS: The saline infusion significantly increased perceived knee pain from 0 to 2.8 cm. The ice/transcutaneous electrical nerve stimulation treatment significantly reduced perceived knee pain by 35%, six minutes after the treatment initiation. Perceived knee pain remained reduced until eight minutes after the treatment termination. The knee pain significantly decreased peak gluteus medius, vastus lateralis, and vastus medialis activation during running, each by an average of 17% plus/minus 6%; however, none of these decreases were resolved via the therapeutic treatment. Neither the knee pain nor the therapeutic treatment significantly affected peak gluteus maximus activation or peak hip adduction angle. INTERPRETATION: The experimental pain model effectively produced anterior knee pain and decreased muscle activation during running. The simultaneous ice/transcutaneous electrical nerve stimulation treatment effectively decreased anterior knee pain, but did not restore running neuromechanics that were altered due to the pain.

The effectiveness of superimposed neuromuscular electrical stimulation combined with strengthening exercises on patellofemoral pain: A randomized controlled pilot trial.

BACKGROUND: Patellofemoral pain (PFP) is one of the most common disorders of the knee. Neuromuscular electrical stimulation (NMES) is often assumed by clinicians to be an effective adjunctive therapy to quadriceps strengthening. OBJECTIVE: The aim of this study was to assess the efficacy of superimposed NMES combined with strengthening exercises to improve the recovery of quadriceps strength and function in patients with PFP. METHODS: This study was planned as a single blind randomized controlled pilot study. A total of twenty-seven patients diagnosed with PFP were randomly assigned into 2 groups. Patients received superimposed NMES in addition to the standardized program (Group I) or only the standardized program (Group II). The patients in both groups were treated 3 times a week for 6 weeks and followed at 12 weeks. Primary outcome measure was quadriceps isokinetic muscle strength. The changes in dependent variables before treatment, 6th, and 12th weeks were analyzed using a 2 × 3 mixed-model analysis of variance. RESULTS: There were significant improvements in the within groups statistics of all parameters for both groups (p< 0.05). No differences in quadriceps strength, Kujala and Lysholm scores between groups were found at the different time points [F (2, 21) = 0.86; p= 0.12, F (2, 21) = 0.001; p= 0.97, F (2, 21) = 0.12; p= 0.73, respectively]. CONCLUSIONS: The results indicate that superimposed NMES combined with the standardized rehabilitation program has no clinically significant superiority to standardized rehabilitation program alone.

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.

Acute Effects of Hip Mobilization With Movement Technique on Pain and Biomechanics in Females With Patellofemoral Pain: A Randomized, Placebo-Controlled Trial.

CONTEXT: People with patellofemoral pain (PFP) present altered lower-limb movements during some activities. Perhaps, joint misalignment in the hip is one of the reasons for altered movement patterns in people with PFP. Some mobilization techniques have been designed to address joint misalignments. OBJECTIVE: To investigate the acute effects of hip mobilization with movement (MWM) technique on pain and biomechanics during squats and jumps in females with and without PFP. DESIGN: Randomized, placebo-controlled trial. SETTING: Movement analysis laboratory. PATIENTS: Fifty-six physically active females (28 with PFP and 28 asymptomatic) were divided into 4 groups: experimental group with PFP, sham group with PFP, experimental group without PFP, and sham group without PFP. INTERVENTION(S): The experimental groups received MWM for the hip, and the sham groups received sham mobilization. MAIN OUTCOME MEASURES: Pain, trunk, and lower-limb kinematics, and hip and knee kinetics during single-leg squats and landings. RESULTS: After the interventions, no difference between groups was found for pain. The PFP experimental group decreased hip internal rotation during squats compared with the PFP sham group (P = .03). There was no other significant difference between PFP groups for kinematic or kinetic outcomes during squats, as well as for any outcome during landings. There was no difference between asymptomatic groups for any of the outcomes in any of the tasks. CONCLUSIONS: Hip mobilization was ineffective to reduce pain in people with PFP. Hip MWM may contribute to dynamic lower-limb realignment in females with PFP by decreasing hip internal rotation during squats. Therefore, hip MWM could be potentially useful as a complementary intervention for patients with PFP.

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.

Electromyographic activity of the hip and knee muscles during functional tasks in males with and without patellofemoral pain.

BACKGROUND: Patellofemoral pain (PFP) is a common overuse injury in physically active individuals. It is characterized by anterior knee, retropatellar, or prepatellar pain associated with activities that increase patellofemoral joint stress such as squatting, stair ascending and descending, running, jumping, prolonged sitting, and kneeling. The etiology of PFP is believed to be multifactorial. Recently, proximal factors have been shown to influence the biomechanics of patellofemoral joint. OBJECTIVE: The aim of the study was to assess hip and knee muscle activity during single leg stance and single leg squat in males with PFP and a control group without PFP. METHODS: Eighteen males with PFP (age 24.2 ±â€¯4.4 years) and 18 healthy subjects as controls (age 23.5 ±â€¯3.8 years) were included. We evaluated gluteus medius, gluteus maximus, vastus medialis oblique (VMO), and vastus lateralis (VL) electromyographic (EMG) activity. The muscle activity and reaction time of the proposed muscles were assessed during single leg stance and single leg squat tasks. Independent t-test was used to identify significant differences between PFP and control groups. RESULTS: No difference in activity of the gluteus maximus muscle was found in either task (p > 0.5). Significant differences were found in activity of gluteus medius and VMO in both tasks (p < 0.05). VL muscle activity had significant difference in single leg stance (p = 0.01), however, had no significant difference in single leg squat (p = 0.1). No significant differences were found in reaction time of the four studied muscles during both single leg stance and single leg squat (p > 0.5). CONCLUSION: Males with PFP demonstrated altered gluteus medius, VMO, and VL muscle activity during single leg stance and single leg squat compared to healthy subjects. Gluteus maximus activity did not show any changes between groups. Moreover, muscle recruitment patterns were different between PFP and healthy groups.

The Effect of Diacutaneous Fibrolysis on Patellar Position Measured Using Ultrasound Scanning in Patients With Patellofemoral Pain Syndrome.

CONTEXT: Tightness or lack of flexibility of several muscles of the thigh has been associated with patellofemoral joint pain. A tight iliotibial band can lead to laterally located patella and an abnormal patellar tracking pattern. Diacutaneous fibrolysis (DF) is commonly used to reduce muscle tightness, but no studies have evaluated the effects of this technique in the treatment of patients with patellofemoral pain syndrome. OBJECTIVE: To assess the effect of DF on patellar position in patients with patellofemoral pain syndrome. DESIGN: A single-group, pretest-posttest clinical trial. SETTING: University of Zaragoza. PARTICIPANTS: A total of 46 subjects with patellofemoral pain (20 males, 26 females; age: 27.8 [6.9] y). INTERVENTION: Three sessions of DF. MAIN OUTCOME MEASURES: Patellar position measurement using real-time ultrasound scanning; pain intensity measured with visual analog scale and function measured with the Anterior Knee Pain Scale. RESULTS: The application of 3 sessions of DF significantly increased the patellar position at posttreatment evaluation (P < .001) and at 1-week follow-up (P < .001). There was not a significant difference on patellar position between posttreatment and follow-up measurements (P = .28). There were also a statistically significant decrease in pain and increase in function at posttreatment and at 1-week follow-up measurements (P < .001). CONCLUSION: This study found that patellar position, pain intensity, and function were significantly improved after 3 sessions of DF and at 1-week follow-up.

Does leg predomination affect measuring vasti muscle onsets during single leg squatting? A reliability study.

INTRODUCTION: Although measuring vasti muscle onset may reveal whether pain relief is associated with altering this parameter during activities in subjects with patellofemoral pain syndrome (PFPS), it may be necessary to determine whether the inherent properties of the dominant leg influences the reliability of measuring VMO-VL muscle onset. The aim of the present study was to examine the effect of leg predomination on reliability testing of the VMO-VL muscle onset measurement during single leg squatting in healthy subjects. METHODS: The onset of VMO and VL muscles of ten healthy subjects with a right dominant leg was assessed during single leg squatting. Data was collected from the muscle bellies of the VMO and VL. This procedure was performed on the both legs, during three separate single leg squats from a neutral position to a depth of approximately 30° of knee flexion. Subjects were then asked to repeat the test procedure after a minimum of a week's interval. The full wave rectified onsets of VMO and VL were then calculated. RESULTS: There was no significant difference between the VMO-VL onset mean values of paired test of right and left knees. The ICC (intra class correlation coefficient) values during within and between sessions tests showed the poor reliability of these measurements on both knees. CONCLUSION: The low intratester reliability of within and between sessions measurement of VMO-VL onset on the both dominant and non-dominant legs revealed that repeatability of these measurements have little accepted reliability, however similar values of these measurements indicated that leg predomination does not affect the measurements during single leg squatting.

Acute Responses of Strength and Running Mechanics to Increasing and Decreasing Pain in Patients With Patellofemoral Pain.

CONTEXT: Patellofemoral pain (PFP) is typically exacerbated by repetitive activities that load the patellofemoral joint, such as running. Understanding the mediating effects of changes in pain in individuals with PFP might inform injury progression, rehabilitation, or both. OBJECTIVE: To investigate the effects of changing pain on muscular strength and running biomechanics in those with PFP. DESIGN: Crossover study. SETTING: University research laboratory. PATIENTS OR OTHER PARTICIPANTS: Seventeen participants (10 men, 7 women) with PFP. INTERVENTION(S): Each participant completed knee pain-reducing and pain-inducing protocols in random order. The pain-reducing protocol consisted of 15 minutes of transcutaneous electric nerve stimulation (TENS) around the patella. The pain-inducing protocol was sets of 20 repeated single-legged squats (RSLS). Participants completed RSLS sets until either their pain was within at least 1 cm of their pain during an exhaustive run or they reached 10 sets. MAIN OUTCOME MEASURE(S): Pain, isometric hip and trunk strength, and running mechanics were assessed before and after the protocols. Dependent variables were pain, normalized strength (abduction, extension, external rotation, lateral trunk flexion), and peak lower extremity kinematics and kinetics in all planes. Pain scores were analyzed using a Friedman test. Strength and mechanical variables were analyzed using repeated-measures analyses of variance. The α level was set at P < .05. RESULTS: Pain was decreased after the TENS (pretest: 3.10 ± 1.95, posttest: 1.89 ± 2.33) and increased after the RSLS (baseline: 3.10 ± 1.95, posttest: 4.38 ± 2.40) protocols (each P < .05). The RSLS protocol resulted in a decrease in hip-extension strength (baseline: 0.355 ± 0.08 kg/kg, posttest: 0.309 ± 0.09 kg/kg; P < .001). Peak plantar-flexion angle was decreased after RSLS (baseline: -13.97° ± 6.41°, posttest: -12.84° ± 6.45°; P = .003). Peak hip-extension (pretest: -2.31 ± 0.46) and hip-abduction (pretest: -2.02 ± 0.35) moments decreased after both the TENS (extension: -2.15 ± 0.48 Nm/kg, P = .015; abduction: -1.91 ± 0.33 Nm/kg, P = .015) and RSLS (extension: -2.18 ± 0.52 Nm/kg, P = .003; abduction: -1.87 ± 0.36 Nm/kg, P = .039) protocols. CONCLUSIONS: This study presents a novel and effective method of increasing pain in persons with PFP. Functionally increased pain after RSLS coincides with reduced hip-extensor muscle strength and decreased plantar-flexion angle during running. The TENS treatment decreased pain during running in those with PFP but failed to influence strength. Hip moments were reduced by both protocols, which may demonstrate that acute increases or decreases in pain cause runners to change their mechanics.

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.

Is there a role of pulsed electromagnetic fields in management of patellofemoral pain syndrome? Randomized controlled study at one year follow-up.

Patellofemoral pain syndrome (PFPS) is a common cause of recurrent or chronic knee pain in young adults, generally located in the retropatellar region. Etiology is controversial and includes several factors, such as anatomical defects, muscular imbalance, or joint overuse. Good results have been reported with exercise therapy, including home exercise program (HEP). Joint inflammation with increase of pro-inflammatory cytokines levels in the synovial fluid might be seen especially when chondromalacia becomes evident. Biophysical stimulation with pulsed electromagnetic fields (PEMFs) has shown anti-inflammatory effects and anabolic chondrocyte activity. The purpose of this randomized controlled study was to evaluate if the combination of HEP with PEMFs was more effective than HEP alone in PFPS treatment. Thirty-one PFPS patients were enrolled in this study. All patients were instructed to train with HEP. Patients in the PEMFs group associated HEP with PEMFs. Function and pain were assessed with Victorian Institute of Sport Assessment score (VISA), Visual Analog Scale (VAS), and Feller's Patella Score at baseline at 2, 6, and 12 months of follow-up. Drug assumption was also recorded. Increase in VISA score was significantly higher in PEMFs group compared to controls at 6 and 12 months, as well as the increase in the Feller's Patella Score at 12 months. VAS score became significantly lower in the PEMFs group with respect to control group since 6 month follow-up. Pain reduction obtained with PEMFs enhanced practicing therapeutic exercises leading to a better recovery process; this is extremely important in addressing the expectations of young patients, who wish to return to sporting activities.

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.

Comparison of Transcutaneous Electrical Nerve Stimulation and Cryotherapy for Increasing Quadriceps Activation in Patients With Knee Pathologies.

CLINICAL SCENARIO: Proper neuromuscular activation of the quadriceps muscle is essential for maintaining quadriceps (quad) strength and lower-extremity function. Quad activation (QA) failure is a common characteristic observed in patients with knee pathologies, defined as an inability to voluntarily activate the entire alpha-motor-neuron pool innervating the quad. One of the more popular techniques used to assess QA is the superimposed burst (SIB) technique, a force-based technique that uses a supramaximal, percutaneous electrical stimulation to activate all of the motor units in the quad during a maximal, voluntary isometric contraction. Central activation ratio (CAR) is the formula used to calculate QA level (CAR = voluntary force/SIB force) with the SIB technique. People who can voluntarily activate 95% or more (CAR = 0.95-1.0) of their motor units are defined as being fully activated. Therapeutic exercises aimed at improving quad strength in patients with knee pathologies are limited in their effectiveness due to a failure to fully activate the muscle. Within the past decade, several disinhibitory interventions have been introduced to treat QA failure in patients with knee pathologies. Transcutaneous electrical nerve stimulation (TENS) and cryotherapy are sensory-targeted modalities traditionally used to treat pain, but they have been shown to be 2 of the most successful treatments for increasing QA levels in patients with QA failure. Both modalities are hypothesized to positively affect voluntary QA by disinhibiting the motor-neuron pool of the quad. In essence, these modalities provide excitatory afferent stimuli to the spinal cord, which thereby overrides the inhibitory afferent signaling that arises from the involved joint. However, it remains unknown whether 1 is more effective than the other for restoring QA levels in patients with knee pathologies. By knowing the capabilities of each disinhibitory modality, clinicians can tailor treatments based on the rehabilitation goals of their patients. Focused Clinical Question: Is TENS or cryotherapy the more effective disinhibitory modality for treating QA failure (quantified via CAR) in patients with knee pathologies?

Does anterior knee pain severity and function relate to the frontal plane projection angle and trunk and hip strength in women with patellofemoral pain?

The aim of the present study was to determine the relationship between knee pain severity and function with the frontal plane projection angle (FPPA) and trunk and hip peak torque (PT) in women with patellofemoral pain (PFPS). Twenty-two women with PFPS were assessed. Knee pain severity (KPS) was assessed with an 11-point visual analog scale and function with an Anterior Knee Pain Scale. The FPPA was recorded with a digital camera. PT of extensors, abductors, and the lateral rotators of hip and lateral core stability were measured with a handheld dynamometer. FPPA was the only predictor for the KPS. Regarding predictors of function, PT of lateral core stability and the extensor and abductor of the hip explained 41.4% of the function. Increase in FPPA was associated with greater KPS, and the lowest PT of lateral core stability, hip abductors, and extensors was associated with lower function in women with PFPS.

Reliability testing of vasti activity measurements in taped and untaped patellofemoral conditions during single leg squatting in healthy subjects: a pilot study.

INTRODUCTION: Measuring vasti muscles activity may provide reliable evidence for patellar taping to correct probable malalignment in subjects with patellofemoral pain syndrome (PFPS). The aim of present study was to examine the reliability of vasti activity measurements in different patellofemoral conditions during squatting in healthy subjects. METHODS: Using an electromyography (EMG) unit, the ratio amplitudes and onsets of VMO and VL muscles of twelve healthy subjects were assessed during single leg squatting. Data was collected from surface electrodes placed over the muscle bellies of the VMO and VL. This procedure was performed on the right knees, before (BT), during (WT) and shortly after patellar taping (SAT). RESULTS: While the CV (coefficient of variation), ICC (intra class correlation coefficient), LSD (least significant difference) and SEM (standard error of measurement) values revealed the high reliability of the VMO/VL amplitude measurements during single leg squatting (p < 0.05), the related values demonstrated poor to moderate reliability of VMO-VL onset measurements during the similar activity (p > 0.05). CONCLUSION: Reliability tests conducted during the current study showed that, while the relative amplitude of vasti could be used as highly reliable parameter, the muscle onsets of vasti had poor to moderate reliability.

Efeitos da eletroestimulação do músculo vasto medial oblíquo em portadores de síndrome da dor patelofemoral: uma análise eletromiográfica / Effects of electrical stimulation of vastus medialis obliquus muscle in patients with patellofemoral pain syndrome: an electromyographic analysis

CONTEXTUALIZAÇÃO: O uso da eletromiografia de superfície (EMG-S) tem sido considerado como instrumento de avaliação quantitativa na síndrome da dor patelofemoral (SDPF). Tratamentos conservadores objetivam melhorar o alinhamento patelar, e a estimulação elétrica do músculo vasto medial oblíquo (VMO) tem sido considerada por ser seletiva e não causar irritação articular. OBJETIVO: Verificar o efeito de um programa de fortalecimento muscular com estimulação elétrica do VMO na SDPF por meio da capacidade de avaliação da EMG-S. MÉTODOS: Participaram deste estudo 10 mulheres jovens (idade: 23,1±4,9 anos; massa corporal: 66,8±14,0 kg; estatura: 1,63±6,9 cm; IMC: 25,1±5,6 kg/m²) com SDPF unilateral, as quais realizaram o teste funcional de subir degrau para captação da atividade eletromiográfica dos músculos VMO e vasto lateral (VL), antes e após um programa de estimulação elétrica do VMO. A eletroestimulação foi realizada três vezes por semana, durante seis semanas. Foram consideradas, para análise entre VMO e VL, as variáveis razão do tempo do início até o pico de ativação, razão da integral do sinal (teste t para amostras dependentes) e diferença de início de ativação (teste de Wilcoxon), com nível de significância de p<0,05. RESULTADOS: Os resultados mostraram que ocorreu alteração somente no comportamento eletromiográfico relativo à razão da integral do sinal, mostrando que, após o treinamento muscular, ocorreram mudanças na capacidade de geração da força. CONCLUSÃO: O uso da eletroestimulação deve ser considerado no sentido de complementar a abordagem terapêutica conservadora em portadores da SDFP e a análise da razão da integral do sinal de EMG-S, como instrumento de avaliação. Artigo registrado no Australian New Zealand Clinical Trials Registry (ANZCTR) sob o número ACTRN 12609000079246.

BACKGROUND: The use of surface electromyography (SEMG) has been considered a tool for quantitative assessment of patellofemoral pain syndrome (PFPS). Conservative treatments aim to improve patellar alignment, and electrical stimulation of the vastus medialis obliquus (VMO) muscle has been considered effective because it is selective and does not cause joint irritation. OBJECTIVE: This study aims to investigate the efficiency of a muscle strengthening program with electrical stimulation of the VMO muscle in PFPS by SEMG. METHODS: A group of ten young women (age: 23.1±4.9 years; body mass: 66.8±14.0 kg; height: 1.63±6.9 cm; BMI: 25.1±5.6 kg/m²) with unilateral PFPS participated in the study. They performed the functional test of stair stepping to capture the electromyographic (EMG) activity of the VMO and vastus lateralis (VL) muscles, before and after a program of electrical stimulation of the VMO muscle. The electrical stimulation was performed three times per week for six weeks. For analysis between the VMO and VL muscles, we considered the variables: ratio of time of onset to peak of activation, ratio of the integrals of the signals (t-test for dependent samples), and difference between onsets of activation (Wilcoxon test), with significance level of p<0.05. RESULTS: The results only showed change in behavior in the EMG signal for the ratio of the integrals of the signals, indicating that changes occurred in the force-generating capacity of the muscle after the training. CONCLUSION: The use of electrical stimulation should be considered to complement the conservative therapeutic approach in patients with PFPS, and the analysis of the ratio of the integrals of the SEMG signals should be considered as an instrument of evaluation. Article registered in the Australian New Zealand Clinical Trials Registry (ANZCTR) under number ACTRN 12609000079246.