The effects of lumbosacral support belts and abdominal muscle strength on functional lifting ability in healthy women.

STUDY DESIGN: This study focused on lumbosacral support belts, abdominal muscle strength, and lifting ability in healthy women. Subjects underwent manual muscle testing to determine muscle strength and performed lifting procedures to determine lifting capacity. OBJECTIVES: The purpose of this study is threefold: 1) to determine the effectiveness of lumbosacral support belts in improving lifting ability in healthy women, 2) to determine if lumbosacral support belts are more effective for those with weak abdominals than those with strong abdominals, and 3) to determine if the maximum amount of weight varies with abdominal muscle strength. SUMMARY OF BACKGROUND DATA: In a review of published literature, one study has addressed the relationship of lumbosacral support belts and lifting capacity. However, no study has examined the use of lumbosacral support belts and lifting capacity in a female population. METHODS: A convenient sample of 69 healthy women, aged 20 to 40 years, participated in this study. Subjects were categorized into one of three groups based on lower and upper abdominal muscle strength. Each subject then performed two lifting procedures, one with a lumbosacral support belt and one without, to determine two maximum lifts. RESULTS: Women between the ages of 20 and 40 years could lift approximately 1.0 kg more weight from the floor to waist height with the lumbosacral support belt. The maximum weight lifted varied with abdominal strength. Lumbosacral support belts were not more effective for those with weak abdominals than those with strong abdominals. CONCLUSIONS: When applied properly and used in conjunction with proper lifting technique, lumbosacral support belts slightly improved lifting ability in healthy women. The magnitude of the increase, although statistically significant, is not sufficient to advocate the use of lumbosacral support belts to increase lifting capacity.

Lumbar curvature in standing and sitting in two types of chairs: relationship of hamstring and hip flexor muscle length.

A purpose of this study was to determine the difference in the lumbar curves of subjects while they stood compared with while they sat in two chairs with different seat angles--the Balans Multi-Chair (BMC) and a standard conventional chair (SCC). An additional purpose was to determine the relationship between lumbar curvature and 1) anthropometric factors and hamstring and hip flexor muscle length during standing and during sitting in the two chairs and 2) amount of time spent sitting. Sixty-one men between 20 and 30 years of age served as subjects. Lumbar curve measurements were taken with a flexible ruler with the subjects first standing and then sitting in the two chairs. Hamstring and hip flexor muscle lengths were indicated by range-of-motion measurements taken with a gravity goniometer. Age, number of hours spent sitting per day, upper body length, and right leg length also were recorded. Subjects had significantly more lumbar extension when they sat in the BMC than when they sat in the SCC. Hip flexor length was the only factor that appeared to relate significantly to the difference between the standing lumbar curve and the lumbar curves in the BMC and the SCC.

Balance performance, force production, and activity levels in noninstitutionalized men 60 to 90 years of age.

The purpose of this study was to collect and analyze balance and muscle performance data obtained from 54 men aged 60 to 90 years. Balance was tested using the sharpened Romberg test (SR) and the one-legged stance test (OLST) on each foot with eyes open and eyes closed. A strain-gauge-based quantitative muscle tester (QMT) was used to measure force production. All torque values were normalized as a percentage of body weight. A self-report of activity level also was recorded. The results indicated that OLST scores and normalized torques of the hip flexors, extensors, and abductors had a positive correlation and that SR scores and normalized torques of the hip extensors and right hip abductors had a positive correlation. Subjects who considered themselves to be very active had a significantly higher SR eyes-closed balance time as compared with those who rated themselves as less active. Subjects who considered themselves to be very active also had significantly higher normalized torque values for most muscle groups tested. Negative relationships were shown between age and balance time and between age and force production.

Balance performance and step width in noninstitutionalized, elderly, female fallers and nonfallers.

The purposes of this study were to compare age, static balance performance, and step-width variables between elderly noninstitutionalized women with and without a history of falls and to determine the relationship between balance performance and step width. Each subject performed a maximum of three timed trials on the sharpened Romberg and one-legged stance tests with eyes open and with eyes closed. The first and best trial measurements were used for analysis. Each subject walked on paper walkways making ink prints for step-width measurements. The mean and the variability of each subject's step-width measurements were used for analysis. Data from 110 women, aged 60 to 89 years, were analyzed. The fallers (n = 26) had significantly lower values than the nonfallers (n = 84) on the best trial of the sharpened Romberg test in the eyes-open condition (t = 1.98, df = 108, p less than .05). No significant differences between fallers and nonfallers were revealed in age, the mean and variability of step width, the first trials of the balance tests, and the best trials on the other balance tests. For the total group, the mean measurements on the first trials were significantly lower than those on the best trials for each balance test. Small, but statistically significant (p less than .05), negative relationships existed between balance performance and the mean and variability of step width. The results of this study indicate that the methods of measuring balance and step width are clinically applicable, and the data of patients from a similar population sample may be compared with the data established in this study.

Balance performance among noninstitutionalized elderly women.

Descriptive data were collected regarding static standing balance of 71 noninstitutionalized elderly women as they performed two timed balance tests. All subjects performed the sharpened Romberg test and the one-legged stance test on each foot in four test conditions: 1) eyes open, 2) eyes closed, 3) shoes on, and 4) shoes off. Subjects were grouped and analyzed according to the following age ranges: 1) 60 to 64 years, 2) 65 to 69 years, 3) 70 to 74 years, 4) 75 to 79 years, and 5) 80 to 86 years. The best time of three trials was used for data analysis. The maximum balance time for the sharpened Romberg test was 60 seconds. For the one-legged stance test, a maximum balance time was 30 seconds. No significant difference was found between right and left or dominant and nondominant limbs while performing the one-legged stance test. No significant difference was found in mean balance time between subjects who had fallen versus those who had not fallen, nor between shoes-on and shoes-off test performance. Subjects' performance on the eyes-open test was consistently superior to their eyes-closed test performance (p less than .0001). The one-legged stance test mean balance time decreased significantly as age increased. More subjects reached the maximum balance time on the sharpened Romberg test than on the one-legged stance test. The results of this study indicate that additional research is needed in the area of balance maintenance among the elderly population.

Comparison of cyclic and sustained passive stretching using a mechanical device to increase resting length of hamstring muscles.

The purpose of this study was to compare the effects of cyclic versus sustained passive stretching with a mechanical device on resting hamstring muscles' length. Group 1 subjects (5 men, 17 women) underwent cyclic stretching of their right hamstring musculature, and Group 2 subjects (5 men, 16 women) underwent sustained stretching of their right hamstring musculature. The stretching procedures were performed for 15 minutes on 5 consecutive days. A follow-up examination of the subjects' relative knee flexion range of motion was made one week posttreatment. The Group 1 subjects had a mean ROM increase of 15.4 +/- 5.0 degrees after the five stretching treatments and maintained a mean ROM increase of 10.4 +/- 5.5 degrees on the follow-up examination (p less than .001). In Group 2, the five stretching treatments resulted in a mean ROM increase of 13.4 +/- 4.4 degrees, and a mean increase of 7.9 +/- 4.0 degrees was maintained on the follow-up examination (p less than .001). Linear regression analysis revealed that initial ROM, sex, and treatment method significantly contributed to increases in ROM from Day 1 of treatment to the follow-up examination (F = 6.04; df = 4,36; p less than .0008). The cyclic stretching method resulted in a greater gain in ROM when the other variables were considered. Predicted values of ROM increases were also examined and discussed.

Effect of inherent muscle length on isometric plantar flexion torque in healthy women.

This study investigated the relationship between inherent muscle length and torque production in 59 healthy women. We recorded nondominant ankle range-of-motion values for each subject. These values were partitioned into quartiles for two knee positions. Women with "loose" plantar flexor muscles comprised the first quartile, and those with "tight" plantar flexor muscles the fourth quartile. Tight- and loose-muscle groups were established for the 0-degree (fully extended) and 90-degree (flexed) knee test positions for data analysis. Torque measurements were obtained using an isokinetic testing apparatus. We asked each subject to perform a maximal isometric (static) plantar flexion contraction at each of three ankle positions: 7 degrees of dorsiflexion (angle A), 0 degrees or neutral (angle B), and 30 degrees of plantar flexion (angle C). Data analysis was performed using an analysis of variance for repeated measures. Results indicated that torque produced by the tight-muscle groups was significantly greater than the torque produced by the loose-muscle groups at both knee positions (p less than .05). Additionally, the ankle ROM data obtained suggest normative data different from those currently prevalent in the literature. Findings of this study may prove valuable in the rehabilitation of ankle injuries and could be beneficial especially to physical therapists in understanding more about normal ankle function.

Length and circumference measurements in one-joint and multijoint muscles in rabbits after immobilization.

In this article, we compared changes in the length and circumference of the soleus and the plantaris muscles in rabbits. The rabbits were assigned to a nonimmobilized external control group (n = 4), an experimental shortened-position group (n = 10), or an experimental lengthened-position group (n = 9). One hind limb of each animal in the experimental groups was immobilized in a cast for four weeks to put the muscles in either a shortened or lengthened position. The contralateral limb served as an internal control for the animals in the experimental groups. After the immobilization period, the limbs were fixed in situ, the muscles were dissected, and length and circumference measurements were taken. In both experimental conditions, the immobilized soleus muscles were shorter than their contralateral counterparts (p less than .05); the length of the plantaris muscles did not change. The immobilized muscles had decreased circumference values regardless of the immobilization angle. When compared with the control condition, the shortened soleus muscles had a greater decrease in circumference than did the plantaris muscles. More connective tissue was observed in the muscle bellies of the soleus after immobilization than in the plantaris. Similar significant changes (p less than .05) were found in the nonimmobilized limbs of the animals in the experimental groups. Specifically, the soleus muscles demonstrated length and circumference changes, whereas the plantaris muscles showed changes only in circumference. These findings suggest that when a weight-bearing limb is immobilized, adaptations in gross muscle length and circumference are to be expected in the involved and uninvolved limbs. An assessment of similar adaptations in humans should be a part of the evaluation during recovery.

Review of length-associated changes in muscle. Experimental evidence and clinical implications.

Movement dysfunction that may be caused by length-associated changes in muscle is a problem of people treated by physical therapists. The purpose of this article is to review the literature related to length-associated changes in muscle. An analysis of length-associated changes in animal and human studies is presented. The methods used to produce the changes in animals are discussed, and the clinical implications of the length-associated changes in muscle are suggested.

Selected primitive reflexes in children with cerebral palsy: consistency of response.

The purpose of this study was to determine the consistency of reflex responses of subjects in varying behavioral states. The following selected primitive reflexes were examined in children with spastic quadriplegic cerebral palsy: tonic labyrinthine, asymmetrical tonic neck, symmetrical tonic neck, crossed extension, and Moro. Our hypothesis was that a subject's reflex responses would vary as a function of his behavioral state. Ten children, ages 3 to 6 years, participated in the study. Reflex responses were elicited using a specified protocol. A behavioral-state scale was defined, and the subject's behavioral state was noted before each reflex stimulus was applied. Each subject completed eight test sessions. Test sessions were videotaped with portable video equipment. Results of the study indicated a significant inverse relationship between progression on the behavioral-state scale and consistency of reflex responses; the higher the numerical rating, the less the consistency of response. Findings of our study support those who recommend optimal states for testing and indicate that caution should be used when interpreting test results based on a single examination.