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1.  Reduced Quadriceps Activation After Lumbar Paraspinal Fatiguing Exercise 
Journal of Athletic Training  2006;41(1):79-86.
Context: Although poor paraspinal muscle endurance has been associated with less quadriceps activation (QA) in persons with a history of low back pain, no authors have addressed the acute neuromuscular response after lumbar paraspinal fatiguing exercise.
Objective: To compare QA after lumbar paraspinal fatiguing exercise in healthy individuals and those with a history of low back pain.
Design: A 2 × 4 repeated-measures, time-series design.
Setting: Exercise and Sport Injury Laboratory.
Patients or Other Participants: Sixteen volunteers participated (9 males, 7 females; 8 controls and 8 with a history of low back pain; age = 24.1 ± 3.1 years, height = 173.4 ± 7.1 cm, mass = 72.4 ± 12.1 kg).
Intervention(s): Subjects performed 3 sets of isometric lumbar paraspinal fatiguing muscle contractions. Exercise sets continued until the desired shift in lumbar paraspinal electromyographic median power frequency was observed. Baseline QA was compared with QA after each exercise set.
Main Outcome Measure(s): An electric burst was superimposed while subjects performed a maximal quadriceps contraction. We used the central activation ratio to calculate QA = (FMVIC/[FMVIC + FBurst])* 100, where F = force and MVIC = maximal voluntary isometric contractions. Quadriceps electromyographic activity was collected at the same time as QA measurements to permit calculation of median frequency during MVIC.
Results: Average QA decreased from baseline (87.4% ± 8.2%) after the first (84.5% ± 10.5%), second (81.4% ± 11.0%), and third (78.2% ± 12.7%) fatiguing exercise sets. On average, the group with a history of low back pain showed significantly more QA than controls. No significant change in quadriceps median frequency was noted during the quadriceps MVICs.
Conclusions: The quadriceps muscle group was inhibited after lumbar paraspinal fatiguing exercise in the absence of quadriceps fatigue. This effect may be different for people with a history of low back pain compared with healthy controls.
PMCID: PMC1421484  PMID: 16619099
superimposed burst technique; quadriceps muscle inhibition; low back pain
2.  Quadriceps Inhibition After Repetitive Lumbar Extension Exercise in Persons With a History of Low Back Pain 
Journal of Athletic Training  2006;41(3):264-269.
Context: A neuromuscular relationship exists between the lumbar extensor and quadriceps muscles during fatiguing exercise. However, this relationship may be different for persons with low back pain (LBP).
Objective: To compare quadriceps inhibition after isometric, fatiguing lumbar extension exercise between persons with a history of LBP and control subjects.
Design: A 2 × 3 factorial, repeated-measures, time-series design with independent variables of group (persons with a history of LBP, controls) and time (baseline, postexercise set 1, postexercise set 2).
Setting: University research laboratory.
Patients or Other Participants: Twenty-five subjects with a history of LBP were matched by sex, height, and mass to 25 healthy control subjects.
Intervention(s): Electromyography median frequency indexed lumbar paraspinal muscular fatigue while subjects performed 2 sets of isometric lumbar extension exercise. Subjects exercised until a 15% downward shift in median frequency for the first set and a 25% shift for the second set were demonstrated.
Main Outcome Measure(s): Knee extension force was measured while subjects performed an isometric maximal quadriceps contraction. During this maximal effort, a percutaneous electric stimulus was applied to the quadriceps, causing a transient, supramaximal increase in force output. We used the ratio between the 2 forces to estimate quadriceps inhibition. Quadriceps electromyographic activity was recorded during the maximal contractions to compare median frequencies over time.
Results: Both groups exhibited significantly increased quadriceps inhibition after the first (12.6% ± 10.0%, P < .001) and second (15.2% ± 9.7%, P < .001) exercise sets compared with baseline (9.6% ± 9.3%). However, quadriceps inhibition was not different between groups.
Conclusions: Persons with a history of LBP do not appear to be any more or less vulnerable to quadriceps inhibition after fatiguing lumbar extension exercise.
PMCID: PMC1569566  PMID: 17043693
superimposed burst technique; neuromuscular activity; knee
3.  Exergaming and Static Postural Control in Individuals With a History of Lower Limb Injury 
Journal of Athletic Training  2013;48(3):314-325.
Context:
Therapeutic exercise programs that incorporate real-time feedback have been reported to enhance outcomes in patients with lower extremity joint injuries. The Wii Fit has been purported to improve balance, strength, flexibility, and fitness.
Objective:
To determine the effects of Wii Fit rehabilitation on postural control and self-reported function in patients with a history of lower limb injury.
Design:
Single-blinded, randomized controlled trial.
Setting:
Laboratory.
Patients or Other Participants:
Twenty-eight physically active participants with a history of lower limb injuries were randomly assigned to 1 of 3 groups (9 Wii Fit, 10 traditional, 9 control).
Intervention(s):
Intervention groups performed supervised rehabilitation 3 d/wk for a total of 12 sessions.
Main Outcome Measure(s):
Time to boundary (TTB) and the Star Excursion Balance Test (SEBT) were conducted at baseline, 2 weeks, and 4 weeks. Self-reported function was measured at baseline and 4-week follow-up. Between-groups differences were compared using repeated-measures multivariate analysis of variance.
Results:
With the eyes open, both intervention groups improved (P < .05) in the mean and the SD of the TTB anterior-posterior minima. In the eyes-closed condition, a time main effect (P < .05) for absolute TTB medial-lateral minima was observed. A time main effect was also noted in the posteromedial and posterolateral reach directions of the SEBT. When the scores for each group were pooled, improvement (P < .05) in self-reported function was demonstrated at 4-week follow-up.
Conclusions:
Rehabilitation using the Wii Fit and traditional exercises improved static postural control in patients with a history of lower extremity injury.
doi:10.4085/1062-6050-48.2.04
PMCID: PMC3655744  PMID: 23675790
balance; rehabilitation; time to boundary; virtual reality
4.  Mechanisms and Management of Stress Fractures in Physically Active Persons 
Journal of Athletic Training  2002;37(3):306-314.
Objective: To describe the anatomy of bone and the physiology of bone remodeling as a basis for the proper management of stress fractures in physically active people.
Data Sources: We searched PubMed for the years 1965 through 2000 using the key words stress fracture, bone remodeling, epidemiology, and rehabilitation.
Data Synthesis: Bone undergoes a normal remodeling process in physically active persons. Increased stress leads to an acceleration of this remodeling process, a subsequent weakening of bone, and a higher susceptibility to stress fracture. When a stress fracture is suspected, appropriate management of the injury should begin immediately. Effective management includes a cyclic process of activity and rest that is based on the remodeling process of bone.
Conclusions/Recommendations: Bone continuously remodels itself to withstand the stresses involved with physical activity. Stress fractures occur as the result of increased remodeling and a subsequent weakening of the outer surface ofthe bone. Once a stress fracture is suspected, a cyclic management program that incorporates the physiology of bone remodeling should be initiated. The cyclic program should allow the physically active person to remove the source of the stress to the bone, maintain fitness, promote a safe return to activity, and permit the bone to heal properly.
PMCID: PMC164361  PMID: 16558676
bone remodeling; rehabilitation; stress reaction
5.  Strength, Functional Outcome, and Postural Stability After Anterior Cruciate Ligament Reconstruction 
Journal of Athletic Training  2002;37(3):262-268.
Objective: To compare postural stability, single-leg hop, and isokinetic strength measurements in subjects after anterior cruciate ligament (ACL) reconstruction with an age- and activity-matched control group.
Design and Setting: Subjects reported to a sports medicine/athletic training research laboratory for testing. Subjects reported for one testing session for a total test time of 1 hour.
Subjects: Twenty subjects with ACL reconstructions (ACLRs) and 20 age- and activity-matched controls were selected to participate in this study. An arthroscopically assisted central one-third bone-patellar tendon procedure was used to repair the ACLs.
Measurements: We measured concentric and eccentric peak torque (Nm) measurements of the knee extensors and flexors at 120° and 240°/second on an isokinetic dynamometer. Unilateral and bilateral dynamic postural stability was measured as a stability index in the anterior-posterior and medial-lateral planes with the Biodex Stability System. We tested single-leg hop for distance to measure objective function.
Results: We found no significant difference between the ACLR and control subjects for stability index or knee-flexion peak torque scores. On the single-leg hop for distance, the ACLR subjects hopped significantly shorter distances with the involved limb than the uninvolved limb. Furthermore, the ACLR subjects' single-leg hop distance was significantly less when the involved limb was compared with the control-group matched involved limb, and the ACLR subjects performed significantly better when the uninvolved limb was compared with the control-group matched uninvolved limb. The ACLR subjects produced significantly greater torque in the uninvolved leg than in the involved leg. In addition, the peak torque was significantly less for the involved limb in the ACLR group when compared with the matched involved limb of the control group.
Conclusions: After ACLR (mean = 18 ± 10 months), single-leg hop-for-distance scores and quadriceps strength were not within normal limits when compared with the contralateral limb. Our results suggest that bilateral and single-limb postural stability in the ACLR group was not significantly different than the control group at an average follow-up of 18 months after surgery.
PMCID: PMC164354  PMID: 12937583
ACL reconstruction; balance; single-leg hop; isokinetic strength; Biodex stability system
6.  Effect of Duration and Amplitude of Direct Current when Lidocaine Is Delivered by Iontophoresis 
Pharmaceutics  2011;3(4):923-931.
Dosage for the galvanic stimulation for iontophoresis varies. Clinicians manipulate the duration or the amplitude of the current, but it is not known which is more effective. We compared the anesthetic effect of lidocaine HCL (2%) by manipulating the current parameters on 21 healthy volunteers (age: 21.2 ± 4.2, height 170.7 ± 10.2 cm, mass 82.1 ± 19.2 kg). Three conditions were administered in a random order using a Phoresor II® with 2 mL, 2% lidocaine HCL in an iontophoresis electrode. (1) HASD (40 mA*min): High amplitude (4 mA), short duration (10 min); (2) LALD (40 mA.min): Low amplitude (2 mA), long duration (20 min); (3) Sham condition (0 mA, 20 min). Semmes-Weinstein monofilament (SWM) scores were taken pre and post intervention to measure sensation changes. Two-way ANOVA with repeated measures was used to compare sensation. Both iontophoresis treatments: LALD (4.2 ± 0.32 mm) and HASD (4.2 ± 0.52 mm) significantly increased SWM scores, indicating an increase in anesthesia, compared to the sham condition (3.6 ± 0.06 mm) p < 0.05. Neither LALD nor HASD was more effective and there was no difference in anesthesia with the sham. Lidocaine delivered via iontophoresis reduces cutaneous sensation. However, there was no benefit in either a HASD or LALD treatment.
doi:10.3390/pharmaceutics3040923
PMCID: PMC3857064  PMID: 24309314
percutaneous drug delivery; physical therapy; transdermal; electrical stimulation; electroporation
7.  Treatment of a female collegiate rower with costochondritis: a case report 
Rib injuries are common in collegiate rowing. The purpose of this case report is to provide insight into examination, evaluation, and treatment of persistent costochondritis in an elite athlete as well as propose an explanation for chronic dysfunction. The case involved a 21 year old female collegiate rower with multiple episodes of costochondritis over a 1-year period of time. Symptoms were localized to the left third costosternal junction and bilaterally at the fourth costosternal junction with moderate swelling. Initial interventions were directed at the costosternal joint, but only mild, temporary relief of symptoms was attained. Reexamination findings included hypomobility of the upper thoracic spine, costovertebral joints, and lateral ribs. Interventions included postural exercises and manual therapies directed at the lateral and posterior rib structures to improve rib and thoracic spine mobility. Over a 3-week time period pain experienced throughout the day had subsided (visual analog scale – VAS 0/10). She was able to resume running and elliptical aerobic training with minimal discomfort (VAS 2/10) and began to reintegrate into collegiate rowing. Examination of the lateral ribs, cervical and thoracic spine should be part of the comprehensive evaluation of costochondritis. Addressing posterior hypomobility may have allowed for a more thorough recovery in this case study.
doi:10.1179/106698110X12640740712653
PMCID: PMC3101071  PMID: 21655387
Costochondritis; Joint mobilization; Rib; Thoracic spine
8.  Rehabilitation Considerations of a Brachial Plexus Injury with Complete Avulsion of C5 and C6 Nerve Roots in a College Football Player 
Sports Health  2009;1(5):370-375.
Severe brachial plexus injuries are rare in sports, but they have catastrophic results with a significant loss of function in the involved upper extremity. Nerve root avulsions must be timely managed with prompt evaluation, accurate diagnosis, and surgical treatment to optimize the potential for a functional outcome. This case report describes the mechanism of injury, diagnostic evolution, surgical management, and rehabilitation of a college football player who sustained a traumatic complete nerve root avulsion of C5 and C6 (upper trunk of the brachial plexus). Diagnostics included clinical evaluation, magnetic resonance imaging, computed tomography myelogram, and electromyogram. Surgical planning included nerve grafting and neurotization (nerve transfer). Rehabilitation goals were to bring the hand to the face (active biceps function), to stabilize the shoulder for abduction and flexion, and to reduce neuropathic pain. Direct current stimulation, bracing, therapeutic exercise, and biofeedback were used to maximize the use of the athlete’s upper extremity. Although the athlete could not return to sport or normal function by most standards, his results were satisfactory in that he regained an ability to perform many activities of daily living.
doi:10.1177/1941738109343544
PMCID: PMC3445178  PMID: 23015895
nerve root avulsion; preganglionic; brachial plexus; nerve graft
9.  Contribution of Hamstring Fatigue to Quadriceps Inhibition Following Lumbar Extension Exercise 
The purpose of this study was to determine the contribution of hamstrings and quadriceps fatigue to quadriceps inhibition following lumbar extension exercise. Regression models were calculated consisting of the outcome variable: quadriceps inhibition and predictor variables: change in EMG median frequency in the quadriceps and hamstrings during lumbar fatiguing exercise. Twenty-five subjects with a history of low back pain were matched by gender, height and mass to 25 healthy controls. Subjects performed two sets of fatiguing isometric lumbar extension exercise until mild (set 1) and moderate (set 2) fatigue of the lumbar paraspinals. Quadriceps and hamstring EMG median frequency were measured while subjects performed fatiguing exercise. A burst of electrical stimuli was superimposed while subjects performed an isometric maximal quadriceps contraction to estimate quadriceps inhibition after each exercise set. Results indicate the change in hamstring median frequency explained variance in quadriceps inhibition following the exercise sets in the history of low back pain group only. Change in quadriceps median frequency explained variance in quadriceps inhibition following the first exercise set in the control group only. In conclusion, persons with a history of low back pain whose quadriceps become inhibited following lumbar paraspinal exercise may be adapting to the fatigue by using their hamstring muscles more than controls.
Key PointsA neuromuscular relationship between the lumbar paraspinals and quadriceps while performing lumbar extension exercise may be influenced by hamstring muscle fatigue.QI following lumbar extension exercise in persons with a history of LBP group may involve significant contribution from the hamstring muscle group.More hamstring muscle contribution may be a necessary adaptation in the history of LBP group due to weaker and more fatigable lumbar extensors.
PMCID: PMC3818676  PMID: 24198683
Superimposed burst technique; electromyography; spectral median frequency; correlation and regression; low back pain

Results 1-9 (9)