Arthur J. Nitz

Postmeniscectomy tourniquet palsy and functional sequelae

A pattern of variability was noted in the rehabilitative progress of patients undergoing knee surgery. Forty- eight patients who underwent routine medial or lateral meniscectomy were studied in a controlled, random ized, prospective investigation designed to identify electromyographic (EMG) and functional deficits as sociated with using a pneumatic tourniquet in knee surgery. The control group (24 individuals) underwent knee surgery without the use of a tourniquet. Six weeks postoperatively all patients were studied by EMG and functionally by determining the single leg vertical leap of the affected leg and expressing this as a percentage of that accomplished by the sound leg. The results were: (1) 17 of 24 (71 %) of the tourniquet group had EMG evidence of denervation and a func tional capacity of 39% of the normal leg. (2) 7 of 24 (29%) of the tourniquet group had no evidence of denervation and a 71 % functional capacity. (3) The control group had no evidence of denervation and a functional capacity of 79%. Of the patients on whom a tourniquet was used, total tourniquet time and pressure did not vary signifi cantly between those patients who demonstrated EMG findings and those who did not. Arthrotomy in the absence of a tourniquet required more attention to hemostasis, but did not present overwhelming dif ficulty. Operative time was slightly prolonged. This investigation suggests that the ideal of early return to functional activity after knee surgery can best be accomplished by avoiding use of a pneumatic tourni quet.

Nerve injury and Grades II and III ankle sprains

Nerve injuries associated with inversion sprains of the ankle have been mentioned in the literature on a case presentation basis only. Sixty-six consecutive patients with Grade II (30) and Grade III (36) ankle sprains were examined by electromyography 2 weeks after injury to determine the presence and distribution of nerve inju ries. Ankle active range of motion (AROM) and the number of weeks postinjury when the patient could heel/toe walk and return to full activity were also noted. Five patients (17%) with Grade II sprains had mild peroneal nerve injury and three (10%) injured the tibial nerve. Clinical measurements were normal by the end of the second week. Thirty-one patients (86%) with Grade III sprains injured their peroneal nerve, while 30 (83%) incurred posterior tibial nerve injury. Ankle AROM was impaired, and heel/toe walking (5.1 weeks) and return to full activity (5.3 weeks) were markedly pro longed. The likely cause of this injury is considered to be a mild nerve traction or a hematoma in the epineural sheath at the bifurcation of the sciatic nerve into pero neal and posterior tibial branches. This report indicates that a consistently high percentage of patients with Grade III ankle sprains sustain a significant injury to both motor nerves in the leg and that rehabilitation time is markedly prolonged.

psychological and physiological parameters of masticatory muscle pain

&NA; The objective of this research was to identify the psychological and physiological variables that differentiate persons reporting masticatory muscle pain (MMP) from normal controls (NC). This study examined the characteristics of 35 MMP patients in comparison to 35 age‐, sex‐, and weight‐matched NCs. All subjects completed a series of standardized questionnaires prior to undergoing a laboratory evaluation consisting of a psychosocial stressor and pressure pain stimulation at multiple body sites. During the evaluation, subjects’ emotional and physiological responses (heart rate, blood pressure, respiration, skin temperature, and muscle activity) were monitored. Results indicated that persons with MMP reported greater fatigue, disturbed sleep, depression, anxiety, menstrual symptoms, and less self‐deception (P’s<0.05) than matched controls. At rest, MMPs had lower end tidal carbon dioxide levels (P<0.04) and lower diastolic blood pressures than the NCs (P<0.02). During laboratory challenge, both groups responded to the standard stressor with significant physiological activity and emotional responding consistent with an acute stress response (P<0.01), but there were no differences between the MMPs and NCs. Muscle pain patients reported lower pressure pain thresholds than did NCs at the right/left masseter and right temporalis sites (P’s<0.05); there were no differences in pressure pain thresholds between MMPs and NCs for the left temporalis (P<0.07) and right/left middle finger sites (P’s>0.93). These results are discussed in terms of the psychological and physiological processes that may account for the development of muscle pain in the masticatory system.

Reduction of pain and EMG activity in the masseter region by trapezius trigger point injection

In this open, uncontrolled trial, 20 patients with upper trapezius muscle trigger point pain and ipsilateral masseter muscle pain received a single trigger point injection of 2% lidocaine solution (without epinephrine) in the upper trapezius muscle. Following the trapezius injection, there was a significant (P < 0.001) reduction in pain intensity ratings for pain in the masseter region. In addition, there was a significant (P < 0.03) reduction in EMG activity in the masseter muscle. Overall, however, a significant relationship between EMG activity in the masseter and the self-report of pain was not found with the present data set. These clinical findings support the contention that sources of deep pain can produce heterotopic sensory and motor changes in distant anatomical regions.

Electromyographic activity of selected trunk and hip muscles during a squat lift. Effect of varying the lumbar posture.

Electromyographic (EMG) activity of selected hip and trunk muscles was recorded during a squat lift, and the effects of two different lumbar spine postures were examined. Seven muscles were analyzed: rectus abdominis (RA), abdominal obliques (AO), erector spinae (ES), latissimus dorsi (LD), gluteus maximus (GM), biceps femoris (BF), and semitendinosus (ST). The muscles were chosen for their attachments to the thoracolumbar fascia and their potential to act on the trunk, pelvis, and hips. Seventeen healthy male subjects participated in the study. Each subject did three squat lifts with a 157-N crate, with the spine in both a lordotic and kyphotic posture. The lift was divided into four equal periods. EMG activity of each muscle was quantified for each period and normalized to the peak amplitude of a maximal voluntary isometric contraction (MVIC). A two-way analysis of variance (ANOVA) for repeated measures was used to analyze the effects of posture on the amplitude and timing of EMG activity during the lift. Two patterns of EMG activity were seen: a trunk muscle pattern (RA, AO, ES, and LD) and a hip extensor pattern (GM, BF, ST). In the trunk muscle pattern (TP), EMG activity was greatest in the first quarter and decreased as the lift progressed. In the hip extensor pattern (HP), EMG activity was least in the first quarter, increased in the second and third quarters, and decreased in the final phase of the lift. Differences (P < .05) were seen among subjects and in the timing of the muscle activity in all muscles.(ABSTRACT TRUNCATED AT 250 WORDS)

Upper extremity tourniquet effects in carpal tunnel release

We studied the presence and extent of upper extremity denervation in limb muscles after surgical release of the carpal tunnel. Sixty consecutive patients were randomly assigned to have the procedure performed with (31 patients) or without (29 patients) tourniquet application. Cervical paraspinal and upper extremity muscles were examined electromyographically 3 weeks before and 3 weeks after carpal tunnel release. Three weeks after the operation 77% of the patients in the tourniquet group had denervation in other than thenar muscles. Only one patient in the control (no tourniquet) group had similar electromyographic abnormalities after surgery. Tourniquet time and pressure did not vary significantly between those patients with or without postoperative forearm denervation. Mean operative time for the tourniquet and control groups was nearly identical. These findings indicate that upper extremity tourniquet application results in subclinical, temporary changes in the muscles of the forearm, probably on the basis of nerve changes and denervation.

Pneumatic tourniquet application and nerve integrity: Motor function and electrophysiology

Limb motor function, leg girth, spontaneous potentials, and compound muscle action potentials were evaluated in a rat animal model at various times after tourniquet application and occlusion of blood flow to the sciatic nerve. The thighs of the animals were compressed by a pneumatic tourniquet at clinically relevant pressures (200, 300, and 400 mm Hg) for 1 to 3 h. Extrinsic blood supply was occluded by ligation of the common iliac and femoral arteries and intrinsic by removing a 12-mm segment of the epineurium from the sciatic nerve. Motor function deficits were noted for 1 to 5 weeks in limbs of animals subjected to tourniquet compression and from 2 to 4 weeks following vascular manipulation. Control leg girths did not change during the experiment whereas girths of tourniquet-compressed legs increased initially and then decreased and remained below control values. Girths of limbs subjected to vascular manipulation were unaltered during the 1st week but decreased in a similar fashion to those of tourniquet-compressed limbs at 3 and 6 weeks. Spontaneous potentials were present and compound muscle action potentials were reduced in animals after tourniquet application and vascular manipulation compared with control values. These electrical abnormalities were most pronounced 1 week after the treatments, progressed toward normalcy during the course of the experiment, but failed to attain control values at the termination of the study. Analysis of electrophysiologic data indicated that magnitude of pressure and duration of compression-produced nerve injury occurred independently in an additive fashion.

Effect of Foot Orthotics on Single- and Double-Limb Dynamic Balance Tasks in Patients With Chronic Ankle Instability

Deficits have been observed in patients with chronic ankle instability while performing dynamic balance tasks. Foot orthotic intervention has demonstrated improvements in static balance following lateral ankle sprain, but the effect is unknown in patients with chronic ankle instability during dynamic balance tasks. Twenty patients with self-reported unilateral chronic ankle instability volunteered for participation. They completed a familiarization session and 2 test sessions separated by 4 weeks. The familiarization session consisted of practice trials of the Star Excursion Balance Test (SEBT) and Limits of Stability (LOS) test, orthotic fitting, and the Cumberland Ankle Instability Tool (CAIT) questionnaire. Patients were instructed to wear the custom-fitted orthotics for at least 4 hours a day to a preferred 8 hours a day for the 4 weeks between sessions. There was an increase in distance reached in the posterolateral direction over the 4-week period in the orthotic condition. There was an increase in distance reached in the medial direction, demonstrating an improvement on the injured side in the orthotic condition after 4 weeks of orthotic intervention. No consistent, meaningful results were observed in the LOS. The involved leg had a significantly lower CAIT score than the uninvolved leg during both sessions, but the involved leg CAIT scores significantly improved over 4 weeks compared with the baseline measure. Orthotic intervention may prove beneficial for improving dynamic balance as measured by the SEBT in individuals with chronic ankle instability and may be a useful adjunct to clinical and sport interventions.

Muscle Stretching as an Alternative Relaxation Training Procedure

The purpose of this program of research was to explore the use of muscle stretching procedures in relaxation training with a clinical population. In the first controlled study, stretching exercises for four muscle groups (obicularis occuli, sternocleidomastoid/trapezius, triceps/pectoralis major, and forearm/wrist flexors) were prepared. A group of people using these procedures (SR, N = 8) was compared to a group using the Bernstein and Borkovec (1973) tense-release (TR; N = 8) techniques for those same muscle groups, as well as compared to an appropriate group of controls (WL; N = 8). Assessment of physiological (multi-site EMG) and subjective (emotions, muscle tension, and self-efficacy) responses showed that persons in the SR displayed less sadness, less self-reported muscle tension at four sites, and less EMG activity on the r.masseter than persons in the TR group. In the second study, 15 subjects were administered an expanded version of the SR relaxation procedures. Results showed that all subjects reported significant decreases in self-reported levels of muscle tension; muscle tension responders showed lowered trapezius EMG and respiration rates and cardiovascular responders showed lowered diastolic blood pressure. The results are discussed in terms of the utility of relaxation procedures based primarily on muscle stretching exercises for lowering subjective and objective states of arousal.

Electromyographic Analysis of Hip Abductor Exercises Performed by a Sample of Total Hip Arthroplasty Patients

Weakness of the hip abductors after total hip arthroplasty may result in pain and/or functional limitation. Non-weight-bearing (NWB) exercises are often performed to target the hip abductors; however, muscle activation of NWB exercises has not been compared to weight-bearing (WB) exercises. Our purpose was to evaluate gluteus medius activation during 2 WB and 2 NWB hip abductor strengthening exercises. Fifteen patients at least 6 weeks post unilateral total hip arthroplasty volunteered for the study. Electromyographic amplitude for each exercise was normalized to each patients maximal voluntary isometric contraction. There were no significant differences in gluteus medius electromyographic amplitudes between the 4 exercises (P = .15). Based on our results, NWB exercises provided no clear benefit in terms of gluteus medius activation when compared to potentially more functional WB exercises in the early postoperative period.