Effects of repetitive handgrip training on endurance, specificity, and cross-education

BACKGROUND AND PURPOSE

Exercise programs are more likely to be successful when they are based on research that predicts the outcomes of such training. This study determined the effect of submaximal rhythmic handgrip training on rhythmic handgrip endurance or work (RHW), isometric handgrip endurance time (IHE), and maximal voluntary isometric contraction for the handgrip force (MVIC) (in newtons).

SUBJECTS

Twenty-four male subjects (mean age=26.2 years) with right-hand dominance were randomly assigned to a regular training group (n=8), a low-level training group (n=8), or a control group (n=8).

METHODS

Rhythmic handgrip work, IHE, and MVIC were determined bilaterally before and after 6 weeks of a rhythmic right handgrip training program using 30% of MVIC. The low-level training group performed daily training with a near-zero load (<0.005% of MVIC).

RESULTS

There was a 1,232% increase in RHW and an 8% decrease in IHE after the training program using 30% of MVIC for the right hand. The left hand showed a 43% increase in RHW after training, whereas the low-level training group showed a 35% increase in RHW. No differences were found between the change in the left-hand RHW of the regular training group and the change in the right-hand RHW of the low-level training group, but both measurements were greater than the change in the control group (6.4%).

CONCLUSION AND DISCUSSION

Submaximal handgrip endurance training at 30% of MVIC had a minimal effect on submaximal IHE and MVIC of the handgrip, but it had a large effect on RHW of the trained extremity. The regular training group and the low-level training group showed similar increases in cross-education, suggesting that cross-education during endurance training is not intensity-dependent.

Health related quality of life in patients with total hip or knee replacement

OBJECTIVE

The Quality of Well Being index (QWB) and the SF-36 are questionnaires that have received widespread use in outcomes research. The relationship between the QWB index and the SF-36 was studied in patients receiving total hip or knee replacement because of primary osteoarthritis, and the health status of these individuals was contrasted to that of the general population.

DESIGN

The QWB and SF-36 were both administered preoperatively and postoperatively and at 3 and 6 months in individuals with hip or knee replacement.

SETTING

A primary care university teaching hospital.

PATIENTS

Forty-three subjects with an age range of 30 to 78 years (mean 58 yrs, SD 10.6) who received total joint replacement, either hip or knee.

RESULTS

The change in the QWB at 3 and 6 months after a total hip replacement or total knee replacement was most associated with the change in general health (.50), bodily pain (.72), and vitality (.62) of the SF-36. Both tools (QWB, SF-36) demonstrated similar levels of responsiveness and the scores were lower than the scores from the general population.

CONCLUSION

The summary score of the QWB and various health concepts of the SF-36 respond similarly after joint replacement from osteoarthritis. The relationship between the change in the QWB and SF-36 depends on the time after surgery (3 vs. 6 months) and the type of joint replacement (knee vs. hip).

Analysis of health-related quality of life and muscle impairment in individuals with amyotrophic lateral sclerosis using the medical outcome survey and the Tufts Quantitative Neuromuscular Exam

OBJECTIVE

The Tufts Quantitative Neuromuscular Exam (TQNE) is commonly used to assess the rate of disease progression in individuals with amyotrophic lateral sclerosis (ALS). The Medical Outcome Study Short Form (SF-36) is a general method to assess health-related quality of life (HRQL). This study examined the relationship between the TQNE and SF-36, established the reliability and responsiveness of each, and contrasted the HRQL between individuals with ALS and the general population.

DESIGN

Subjects (31) completed the SF-36 and TQNE within 1 week to determine reliability. Subjects (17) also completed both the TQNE and SF-36 each month for 1 year after diagnosis of ALS to establish the relationship between the two assessment tools.

SETTING

A primary care university teaching hospital.

PATIENTS

Thirty-one subjects with an age range of 27 to 76 years (mean 59.1, SD 10.32), recently diagnosed with ALS.

RESULTS

Each test was highly reliable and responsive. The intraclass correlations (2, 1) were consistently higher for the TQNE (.93 to .98) than for the SF-36 (.57 to .90). Changes in physical function were correlated to changes in lower extremity force megascores (.48).

CONCLUSION

Both the TQNE and the SF-36 are reliable and responsive and appear important in characterization of patient status after ALS is diagnosed.

Neuromuscular propagation after fatiguing contractions of the paralyzed soleus muscle in humans

We analyzed the M wave and torque after repetitive activation and recovery of the human soleus muscle in individuals with spinal cord injury. Fifteen individuals with complete paralysis had the tibial nerve activated for 330 ms every second with a 20-Hz train. The M wave and torque were analyzed before fatigue, immediately after fatigue, and during recovery. The torque and three M-wave measurements (amplitude, duration, median frequency) changed significantly after fatigue in the chronic group, but the M-wave area was not changed. The M wave was completely recovered after 5 min of rest, even though the torque remained depressed during recovery. The M-wave changes appeared to contribute minimally to the reduced torque in individuals with chronic paralysis. The disassociation in the M-wave-torque relationship during fatigue and recovery suggests, that electrical stimulation under electromyography control is not an ideal method to optimize torque in paralyzed muscle.

The effects of a home exercise program on impairment and health-related quality of life in persons with chronic peripheral neuropathies

BACKGROUND AND PURPOSE

The effects of a home exercise program for persons with chronic peripheral neuropathies (CPN) have not been documented. We compared changes in impairment and health-related quality of life (HRQL) between exercise and control groups, investigated the relationship between HRQL and measures of impairment, and contrasted the HRQL of individuals with CPN to that previously described for the general population.

SUBJECTS

Twenty-eight subjects with CPN, aged 23 to 84 years (mean = 56.2, SD = 14.9), completed the study.

METHODS

Impairment measures included average muscle score (AMS), handgrip force, walking time, and forced vital capacity. The HRQL instrument measured the eight scales of the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) and the component scales. The exercise group (n = 14) completed a 6-week home exercise program. The control group (n = 14) did not participate in a home exercise program.

RESULTS

There was an increase in the AMS in the exercise group compared with the control group. No other between-group differences were found. The exercise group improved in scores on the role limitation scales of the SF-36. The AMS and walking time were moderately correlated with the physical function scale of the SF-36 (r = .55 and -.62, respectively). The SF-36 scores of individuals with CPN were lower than scores previously described for the general population.

CONCLUSION AND DISCUSSION

The home exercise program appears to be an important component of the treatment of persons with CPN. Compared with the general population, patients with CPN appear to have a lower HRQL, but some areas appear to improve following a home exercise program.

Evaluation of health-related quality of life in individuals with vestibular disease using disease-specific and general outcome measures

BACKGROUND AND PURPOSE

The Dizziness Handicap Inventory (DHI) is a condition-specific health status measure for persons with vestibular disease, and the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) is a generic health status assessment. The purposes of this study were (1) to describe the relationship between the DHI and the SF-36, (2) to examine the reliability and responsiveness of these measures for persons in a vestibular rehabilitation program, and (3) to compare health-related quality of life between individuals with vestibular disease and the general population.

SUBJECTS

Ninety-five patients, aged 25 to 88 years (mean = 57.0, SD = 14.9), were assessed.

METHODS

To determine reliability, 20 subjects completed both questionnaires twice, 24 to 48 hours apart. Thirty-one subjects completed both questionnaires before and after 6 to 8 weeks of vestibular rehabilitation to establish responsiveness. To establish the relationship between the two assessment tools, 95 subjects completed both questionnaires.

RESULTS

Each test was moderately to highly reliable (intraclass correlation coefficients [2, 1] = .64-.95), but the tests were poorly to moderately correlated to each other (r = .11-.71). The DHI was more responsive to change than the SF-36. The SF-36 scores of individuals were lower than scores of the general population.

CONCLUSION AND DISCUSSION

The DHI and the SF-36 provide reliable and responsive measurements, but they appear to provide different information about the health status of patients with vestibular disease. Compared with the general population, patients with vestibular disease had lower scores for health-related quality of life, but these scores improved after 6 to 8 weeks of treatment. Future studies should clarify whether this improved health status is due to vestibular rehabilitation.

An electromyographic comparison of abdominal muscle synergies during curl and double straight leg lowering exercises with control of the pelvic position

STUDY DESIGN

This prospective study evaluated the abdominal muscle activity during the Isometric bent knee curl and double straight leg lowering exercise.

OBJECTIVES

To compare the magnitude of the electromyographic activity across the curl and double straight leg lowering exercise and determine if the muscle synergies were specific to a given exercise.

SUMMARY OF BACKGROUND DATA

Abdominal muscle strengthening exercises are frequently recommended in the prevention and rehabilitation of individuals with low back pain. Previous studies comparing the curl exercise with the double straight leg lowering exercise did not support the notion that the double straight leg lowering exercise is more demanding on the abdominal muscles. No previous study examined these two exercises while maintaining a constant pelvic position.

METHODS

Fifteen male subjects had the electromyographic activity of the rectus abdominis, the external oblique, and the internal oblique abdominal muscles evaluated during the curl and double straight leg lowering exercise. The same position of the posterior pelvic tilt was maintained between each exercise using feedback from an electrogoniometer attached to the pelvis.

RESULTS

The double straight leg lowering exercise resulted in significantly greater activation of the abdominal muscles compared with the curl. Two abdominal muscle synergies emerged during the double straight leg lowering exercise: synergy I exhibited high rectus abdominis, high external oblique, and low internal oblique muscle activity, whereas synergy II exhibited low rectus abdominis, high external oblique, and high internal oblique.

CONCLUSIONS

The results support the use of the double straight leg lowering with the posterior pelvic tilt for achieving greater abdominal muscle coactivation in an exercise program.

Effects of electrically induced fatigue on the twitch and tetanus of paralyzed soleus muscle in humans

We analyzed the twitch and summated torque (tetanus) during repetitive activation and recovery of the human soleus muscle in individuals with spinal cord injury. Thirteen individuals with complete paralysis (9 chronic, 4 acute) had the tibial nerve activated every 1,500 ms with a 20-Hz train (7 stimuli) for 300 ms and a single pulse at 1,100 ms. The stimulation protocol lasted 3 min and included 120 twitches and 120 tetani. Minimal changes were found for the acute group. The chronic group showed a significant reduction in the torque and a significant slowing of the contractile speeds of both the twitch and tetanus. The decrease in the peak twitch torque was significantly greater than the decrease in the peak tetanus torque early during the fatigue protocol for the chronic group. The twitch time to peak and half relaxation time were prolonged during fatigue, which was associated with improved fusion of the tetanus torque. At the end of the fatigue protocol, the decrease in the peak twitch torque was not significantly different from the decrease in the peak tetanus torque. After 5 min of rest, the contractile speeds recovered causing the tetanus to become unfused, but the tetanus torque became less depressed than the twitch torque. The differential responses for the twitch and the tetanus suggest an interplay between optimal fusion created from contractile speed slowing and excitation contraction coupling compromise. These issues make the optimal design of functional electrical stimulation systems a formidable task.

Total hip and knee replacement treatment programs: a report using consensus

Physical therapists may use varied treatment protocols for the acute care of patients with to hip or knee replacements. The purpose of this study was to develop, via consensus, a standardized treatment program for patients receiving total hip or knee replacement for primary osteoarthritis. Eighteen clinicians nationwide participated in a three-round consensus process. In Round 1, over 80% of the panel identified exercise, transfers, ambulation, and discharge criteria as the important treatment categories. In Round 2, they reviewed the preliminary physical therapy treatment program and recommended additional exercise regimes. In Round 3, 76% of the panel accepted the final total hip replacement program while 70% of the panel accepted the total knee replacement program. Using the consensus development process, physical therapists may begin to define their treatment programs which is fundamental to establishing a baseline standard of care.

Fatigability, relaxation properties, and electromyographic responses of the human paralyzed soleus muscle

1. The goal of this study was to characterize the fatigability, contractile relaxation properties, electrophysiological responses, and histochemical properties of the human paralyzed soleus muscle to determine its relative plasticity. 2. Acute (< 6 wk, n = 3) and chronic (> 1 yr, n = 10) paralyzed individuals had the tibial nerve activated with a 20-Hz square wave delivered for 330 ms every second for 4 min. The soleus muscle peak torque, one-half relaxation time (1/2RT), normalized maximum rate of relaxation (nMRR), and mass muscle action-potential amplitude (M wave) were computed every 30 s. A soleus muscle biopsy was evaluated for myosin adenosine triphosphatase enzyme (ATPase; pH 9.4, 4.6, and 4.2) and nicotinamide adenine dinucleotide tetrazolium reductase (NADH-TR). 3. In the chronically paralyzed group the torque was significantly reduced within 30 s of the fatigue protocol. The 1/2RT and nMRR were also significantly changed within 30 s, supporting that muscle relaxation was prolonged. No significant changes were present at comparable times during the same 4-min fatigue protocol applied to the acutely paralyzed soleus muscle. M-wave amplitude was significantly reduced in the chronic group, but only at 3 min of the fatigue protocol. Conversely, no significant changes occurred to the M waves of the acute group. 4. The correlation was high between torque and nMRR (r = 0.88-0.97) and torque and 1/2RT (r = 0.88-0.96) for each chronic subject. A close association was also found between 1/2RT and nMRR (r = 0.88-0.92) for each chronic subject. Because these variables changed minimally in the acutely paralyzed group, a lower correlation was present (r = 0.45-0.52). 5. Torque was weakly correlated to M-wave amplitude (r = 0.55) for the chronically paralyzed group. The greatest change in torque occurred at a time (0-65 s) when the least amount of change occurred in the M-wave amplitude, suggesting that the source of fatigue was within the contractile mechanism and not attributable to neuromuscular transmission compromise. 6. Despite a close association between torque and relaxation properties during fatigue of the chronically paralyzed soleus muscle, there was a significant dissociation after 5 min of recovery. Torque recovered to 60%, whereas the relaxation properties were consistently fully recovered. This suggests that the mechanism causing torque reduction covaried with the mechanism leading to prolonged relaxation during fatigue, but during recovery the two mechanisms no longer covaried. M-wave amplitude was also completely recovered at 5 min despite continued torque depression.(ABSTRACT TRUNCATED AT 400 WORDS)

Reliability, validity, and responsiveness of functional tests in patients with total joint replacement

BACKGROUND AND PURPOSE

High-quality measurements are needed to develop meaningful clinical practice databases to assess the effectiveness of physical therapy. This study determined the reliability, validity, and responsiveness of measurements obtained with five functional tests graded with the newly developed Iowa Level of Assistance Scale.

SUBJECTS AND METHODS

Eighty-six patients with total hip or knee replacements were tested at various time periods during their hospitalization. Patients were tested for five functional activities by four therapists to establish the reliability and test responsiveness. The Harris Hip Rating Scale was administered to assess the validity of the functional score.

RESULTS

The weighted Kappa statistic supported good intratester (K = .79-.90) and moderate intertester (K = .48-.78) reliability. The correlation between the Harris Hip Rating Scale scores and the total functional scores was high (r = -.86). The total functional score was responsive to 4 days of therapy postoperatively.

CONCLUSION AND DISCUSSION

The assessment of function using the Iowa Level of Assistance Scale was shown to be highly reliable, valid, and responsive in patients following total hip or knee replacements.

An acute care physical therapy clinical practice database for outcomes research

Clinical practice databases are frequently used to assess outcomes in various medical specialties. Formulating a computerized physical therapy medical record requires standardization of clinical assessments among the users. The purpose of this article is to describe an acute care physical therapy database system that emphasizes high-quality measures of function. The logic underlying the development of a physical therapy computerized medical record is described. Selected uses of the database are demonstrated by projects that assess data quality, generate clinical hypotheses, manage clinical data, develop clinical measures, and generate pilot data on patient variability. Patients seen in physical therapy for total joint replacement, pain, and decreased ambulation were studied to demonstrate some of the present capabilities of the database. Clinical practice databases contribute to the overall research mission, provided the data are of high quality. The use of databases in conjunction with randomized clinical trials may serve an important role in determining effective physical therapy interventions to reduce disability.

Lumbar support thickness: effect on seated buttock pressure in individuals with and without spinal cord injury

We compared the effects of different lumbar support thicknesses on seated buttock pressure in individuals with and without spinal cord injury (SCI). Eighteen subjects with SCI (SCI group) and 18 subjects without SCI (control group) were seated on a pressure-sensing transducer incorporated into an adjustable chair. The output was calibrated so that eight pressure intervals (colors) were displayed. The lumbar support thickness was adjusted to 0, 2.5, 5, and 7.5 cm, and the highest and lowest seated buttock pressures were analyzed. External measurements of the hip angle were taken for each lumbar support condition. High reliability of repeated seated test positions was found (intraclass correlation coefficient = .93). The 5- and 7.5-cm-thick lumbar supports caused a decrease in the highest pressure areas in the control group, but no change in the SCI group. The hip angle was increased with each increment in lumbar support thickness in both groups, but the SCI group's hip angle was consistently less than that of the control group for each lumbar support condition. The results of this study suggest that in individuals with chronic paralysis (greater than or equal to 3 years), the use of a wheelchair lumbar support has a negligible effect on seated buttock pressure.

Phantom limb pain induced in amputee by strong magnetic fields

An amputee (traumatic) experienced increased phantom limb pain when exposed to the magnetic fields of two magnetic resonance imagers. With a visual analog scale used to measure pain, electric stimulation studies demonstrated that the residual limb was unusually sensitive to subthreshold (for muscle twitch) levels of current. The painful symptoms produced mimicked those experienced in the presence of the imagers.

Effect of seat angle and lumbar support on seated buttock pressure

The purpose of this study was to compare the effects of a lumbar support at two seat angles (0 degrees and 10 degrees of posterior tilt) on the area of highest buttock pressure. Twenty able-bodied subjects were seated on a pressure-sensing transducer incorporated into an adjustable chair (ischiobarograph). A video camera on the underside of the transducer detected changes in light levels in direct relation to pressure application. The camera output was processed by a microcomputer system that converted the signal into nine colors, each representing a distinct pressure interval in the range of 0 to more than 500 mm Hg. The microcomputer determined the area of each pressure interval before and after a 10-degree posterior tilt of the seat and lumbar support placement. The results demonstrated high test-retest reliability for each position (r = .95). A significant decrease in the six highest pressure intervals occurred when the lumbar support was used in both the upright and reclined positions (p less than .05). The results of this study have implications for wheelchair-dependent individuals.