Ankle strength assessed by one repetition maximum: A new approach to detect weaknesses in chronic ankle lateral instability

BACKGROUND

Ankle muscle strength should be assessed after a lateral ankle sprain (LAS) because a strength deficit can lead to chronic ankle instability (CAI). No field method is available to obtain quantitative ankle dynamic strength values. This study aimed to assess the reliability of the one-repetition maximal (1-RM) method and to compare ankle muscle strength between healthy volunteers and those with CAI using 1-RM strength assessment approach.

METHODS

We recruited 31 healthy volunteers and 32 with CAI. Dorsiflexor, evertor, and invertor 1-RM were performed twice at a one-week interval. The intraclass correlation coefficient (ICC) and minimal detectable change (MDC) were calculated. Strength values were compared between healthy volunteers and CAI.

RESULTS

The 1-RM method is reliable for assessing ankle dorsiflexor, evertor, and invertor strength, with an ICC ranging from 0.76 to 0.88, and MDC ranging from 19 to 31%. Volunteers with CAI obtained evertor (3.0 vs. 3.5 N/kg), invertor (2.9 vs. 3.7 N/kg), and dorsiflexor (5.9 vs. 6.5 N/kg) strength values that were lower than healthy volunteers (p < 0.05).

CONCLUSION

The 1-RM test can be used in practice to assess evertor, invertor, and dorsiflexor strength during the rehabilitation of LAS. This field method could help practitioners to detect a strength deficit and individualize a strengthening programme if necessary.

Effects of ankle isokinetic training on muscle strength and balance amongst older women with mild Parkinson's disease: A randomised trial

BACKGROUND

Patients with Parkinson's disease frequently experience problems with balance and gait.

OBJECTIVE

This study examined the influences of regular ankle isokinetic muscle strength training on muscle strength and balance ability amongst elderly women with mild Parkinson's disease.

METHODS

A total of 55 elderly women with mild Parkinson's disease were randomly divided into the experimental group (n= 28) and the control group (n= 27) for 16 weeks. The experimental group was trained for 16 weeks by using isokinetic muscle strength training.

RESULTS

After 16 weeks of training in the experimental group, the peak torque (PT) of ankle (average of the left and right sides) dorsiflexion, plantarflexion, eversion and inversion, and the standing balance index revealed that the left and right stability and overall stability indexes significantly increased by 25.9%, 43.5%, 62.7%, 82.8%, 37.1% and 32.2%, respectively (p< 0.05). The experimental group exhibited significantly increased PT of ankle dorsiflexion, plantarflexion, eversion and inversion. Moreover, the left and right stability and overall stability indexes were significantly improved compared with those of the control group (p< 0.05). This study found a linear regression relationship between the PT of ankle inversion and overall stability index.

CONCLUSION

This study determined that ankle isokinetic muscle strength training improved ankle dorsiflexion, plantarflexion, eversion and inversion muscle strength, and balance ability amongst elderly women with mild Parkinson's disease. However, it did not improve stability in the anterior and posterior directions. Ankle inversion muscle strength is more likely to affect overall balance.

Test-Retest Reliability of the One-Repetition Maximum (1RM) Strength Assessment: a Systematic Review

Background

The test–retest reliability of the one-repetition maximum (1RM) test varies across different studies. Given the inconsistent findings, it is unclear what the true reliability of the 1RM test is, and to what extent it is affected by measurement-related factors, such as exercise selection for the test, the number of familiarization trials and resistance training experience.

Objectives

The aim of this paper was to review studies that investigated the reliability of the 1RM test of muscular strength and summarize their findings.

Methods

The PRISMA guidelines were followed for this systematic review. Searches for studies were conducted through eight databases. Studies that investigated test–retest reliability of the 1RM test and presented intra-class correlation coefficient (ICC) and/or coefficient of variation (CV) were included. The COSMIN checklist was used for the assessment of the methodological quality of the included studies.

Results

After reviewing 1024 search records, 32 studies (pooled n = 1595) on test–retest reliability of 1RM assessment were found. All the studies were of moderate or excellent methodological quality. Test–retest ICCs ranged from 0.64 to 0.99 (median ICC = 0.97), where 92% of ICCs were ≥ 0.90, and 97% of ICCs were ≥ 0.80. The CVs ranged from 0.5 to 12.1% (median CV = 4.2%). ICCs were generally high (≥ 0.90), and most CVs were low (< 10%) for 1RM tests: (1) among those without and for those with some resistance training experience, (2) conducted with or without familiarization sessions, (3) with single-joint or multi-joint exercises, (4) for upper- and lower-body strength assessment, (5) among females and males, and (6) among young to middle-aged adults and among older adults. Most studies did not find systematic changes in test results between the trials.

Conclusions

Based on the results of this review, it can be concluded that the 1RM test generally has good to excellent test–retest reliability, regardless of resistance training experience, number of familiarization sessions, exercise selection, part of the body assessed (upper vs. lower body), and sex or age of participants. Researchers and practitioners, therefore, can use the 1RM test as a reliable test of muscular strength.

Segurança, reprodutibilidade, fatores intervenientes e aplicabilidade de testes de 1-RM

Um dos métodos mais utilizados para mensuração da força muscular é o teste de uma repetição máxima (1-RM), tendo em vista a sua versatilidade para aplicação em diferentes exercícios, a especificidade do movimento e o baixo custo operacional. Neste trabalho discutimos as evidências disponíveis a respeito da segurança, da reprodutibilidade, dos fatores intervenientes e da aplicabilidade prática do teste de 1-RM. Com base nas informações disponíveis até o presente momento, o teste de 1-RM parece ser um método seguro do ponto de vista ortopédico e cardiovascular e a sua reprodutibilidade depende, fundamentalmente, da realização de procedimentos de testagem adequados para a estabilização da carga, assim como do controle dos fatores intervenientes os quais podem influenciar no desempenho do teste. Embora a aplicabilidade para o diagnóstico e acompanhamento da força muscular seja ampla, a utilização de testes de 1-RM para a prescrição de treinamento com pesos ainda é bastante discutível.

Arm-curl field test for older women: is it a measure of arm strength?

The facilitative effect of physical activity on age-related decline is well documented. Specifically, it has been found to reduce the risk of dependency. However, physical activity programs for older adults should be carefully designed so that improvements in all aspects of movement and physical capacities are achieved. This means that efficient fitness measurements should be made available for coaches and trainers. The arm-curl test is a common field test known for measuring the strength of upper extremities in older age. The objective of the current study was to determine to what extent this test indeed assesses arm strength as well as other fitness aspects such as arm muscle endurance or general endurance. Scores of the arm-curl test were compared with strength and endurance of elbow flexors measured by an isokinetic dynamometer and general endurance measured by a stress test in 48 independently functioning women (age 72.04 ± 6.28 yr). Significant correlations were indicated between the arm-curl scores and both isokinetic endurance (r = 0.452) and general endurance (r = 0.437); however, a very low nonsignificant correlation was found between the arm-curl and isokinetic maximal strength scores. Coaches must be aware of the fact that the repetitive arm-curl exercise contains a significant aerobic component and thus may contribute to aerobic fitness and arm muscle endurance but not necessarily to arm strength.

Relationships among impairments in lower-extremity strength and power, functional limitations, and disability in older adults

BACKGROUND AND PURPOSE

During the aging process, older adults may experience a loss of strength and power, which then may lead to functional limitations and disability. The purpose of this study was to examine how impairments in lower-extremity strength and power are related to functional limitations and disability in community-dwelling older adults.

SUBJECTS

Thirty older adults (age [X+/-SD], 77.3+/-7.0 years; 25 women and 5 men) with mild to moderate functional limitations participated in this study.

METHODS

Lower-extremity strength, peak power, power at a low relative intensity, and power at a high relative intensity were measured with a pneumatic resistance leg press. Functional limitations and disability were assessed with the Short Physical Performance Battery (SPPB), the Six-Minute Walk Test (SMWT), and the Late Life Function and Disability Instrument (LLFDI).

RESULTS

All measures of strength and power were related to functional limitations. Peak power demonstrated the strongest relationships with SMWT, the SPPB gait speed subscale, and the LLFDI functional limitation component. Power at a high relative intensity demonstrated the strongest relationships to the SPPB total score and the SPPB sit-to-stand subscale score. All measures of strength and power were indirectly related to the LLFDI disability component.

DISCUSSION AND CONCLUSION

Older adults should focus on increasing and maintaining lower-extremity strength and power across a range of intensities in order to decrease functional limitations and disability.

Reliability of maximal voluntary muscle strength and power testing in older men

BACKGROUND

Maximal voluntary muscle strength (MVMS) and leg power are important measures of physical function in older adults. We hypothesized that performing these measures twice within 7-10 days would demonstrate a >5% increase due to learning and familiarization of the testing procedures.

METHODS

Data were collected from three studies in older adult men (60-87 years) and were divided into two cohorts defined by study site and type of exercise equipment. MVMS was assessed in 116 participants using the one-repetition maximum method at two separate study visits for the chest press, latissimus pull-down, leg press, leg flexion, and leg extension exercises along with unilateral leg extension power.

RESULTS

Test-retest scores were not different and did not exceed 0.8 +/- 9.0% in Cohort 1 or 2.3 +/- 9.8% in Cohort 2, except for leg extension, which improved by 6.6 +/- 14.4% (p <.009) and 3.4 +/- 6.8% (p <.016), respectively. Repeat tests were closely correlated with initial tests (all p <.001). Pearson correlation coefficients ranged from 0.74 for leg extension power to 0.96 for leg press. Coefficients of variation were <10% (4.2%-9.0%) for all exercises except for leg extension power, which was 15.5%.

CONCLUSIONS

Our findings demonstrated that test-retest measures of MVMS and power in older adult men do not differ by more than 2.3% except for leg extension, and have relatively low coefficients of variation using data collected from three studies. Moreover, these findings were similar between two study sites using different equipment, which further supports the reliability of MVMS and power testing in older adult men.

Measuring muscle strength for people with chronic obstructive pulmonary disease: retest reliability of hand-held dynamometry

OBJECTIVE

To evaluate the retest reliability and quantify the degree of measurement error when measuring isometric muscle strength with a hand-held dynamometer for people with chronic obstructive pulmonary disease (COPD).

DESIGN

Retest reliability of hand-held dynamometry for 4 muscle groups was assessed on 2 occasions separated by a 2-week interval.

SETTING

Community rehabilitation center.

PARTICIPANTS

Eight men and 4 women (mean age +/- standard deviation, 71.4+/-10.3y) with moderately severe COPD (percentage of predicted forced expiratory volume in 1 second, 41.5%+/-17.7%).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Muscle strength (in kilograms). Statistical analysis was conducted by calculating intraclass correlation coefficients and 95% confidence intervals for both group and individual scores.

RESULTS

All reliability coefficients were greater than .79. Muscle strength would need to increase by between 4% and 18% in groups of people with COPD and between 34% and 58% in a person with COPD to be 95% confident of detecting real changes.

CONCLUSIONS

Hand-held dynamometry is suitable for monitoring change in muscle strength and testing hypotheses for groups of people with COPD. However, hand-held dynamometry is not likely to detect changes in muscle strength for a person with COPD.

Intratester Reliability for Determining an 8-Repetition Maximum for 3 Shoulder Exercises Using Elastic Bands

Context:

Standardization of training load using the 1-repetition maximum (1RM) test cannot be directly applied when using elastic bands as resistance.

Objective:

To determine the intratester reliability for establishing an 8-repetition maximum (8RM) using elastic bands.

Design:

Test–retest.

Participants:

5 men, 10 women, 23–29 years.

Intervention:

An 8RM test was established for 3 shoulder exercises using the Dura-Band® exercise system.

Main Outcome Measures:

The length of the elastic band was recorded. An analysis of variance was performed, and intraclass correlation coefficients (ICC) were calculated for each exercise.

Results:

Intratester reliability for determining the elastic-band length required to establish an 8RM was very high for internal rotation (ICC = .91) and high for external rotation (ICC = .77). The diagonal pull-down 8RM test had moderate reliability (ICC = .65).

Conclusion:

Training load can be reliably standardized in healthy young adults using moderate-to high-resistance elastic bands with a goal-based multiple-RM test.

Reliability of maximal strength testing in older adults

OBJECTIVES

To determine (1) the reliability of a maximal strength test (1 repetition maximum) [1-RM] in older adults and (2) the impact of differing periods of familiarization.

DESIGN

Within-subject, repeated trials of maximal strength.

SETTING

Community-based senior center.

PARTICIPANTS

Forty-seven independently living men (n=16) and women (n=31), with a mean age of 75.4+/-4.7 years.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Systematic error (shift in mean) and random error (% coefficient of variation [%CV]) was assessed between consecutive pairs of 1-RM trials.

RESULTS

For the bench press, systematic error was virtually eliminated for men between trials 2 and 3 (0.7%; 95% confidence interval [CI], -2.7% to 4.3%). The CV was stable (4.7%-7.3%) across all trials in both genders. For the leg press, a significant but clinically small systematic error (3.6%, P<.05; 95% CI, 0.8-6.6) was evident for women between trials 2 to 3. The CV was reduced across trial pairs by 3.3% for men and 0.9% for women. Three versus 6 or more sessions of familiarization produced small clinical differences in systematic error (< or =4.1%) and CV (< or =0.2%) between trials 2 and 3 for both lifts.

CONCLUSIONS

Reliability is an indispensable requirement for valid test outcomes. Our results show that, in this group of older adults, 3 familiarization sessions and 2 to 3 test trials produced highly reliable 1-RM measures. Additional periods of familiarization added little to test reliability. Effective reliability testing for 1-RM is a practical and attainable goal for outcomes based practitioners.

Treatment with oxandrolone and the durability of effects in older men

We investigated the effects of the anabolic androgen, oxandrolone, on lean body mass (LBM), muscle size, fat, and maximum voluntary muscle strength, and we determined the durability of effects after treatment was stopped. Thirty-two healthy 60- to 87-yr-old men were randomized to receive 20 mg oxandrolone/day (n = 20) or placebo (n = 12) for 12 wk. Body composition [dual-energy X-ray absorptiometry (DEXA), magnetic resonance imaging, and (2)H(2)O dilution] and muscle strength [1 repetition maximum (1 RM)] were evaluated at baseline and after 12 wk of treatment; body composition (DEXA) and 1-RM strength were then assessed 12 wk after treatment was discontinued (week 24). At week 12, oxandrolone increased LBM by 3.0 +/- 1.5 kg (P < 0.001), total body water by 2.9 +/- 3.7 kg (P = 0.002), and proximal thigh muscle area by 12.4 +/- 8.4 cm(2) (P < 0.001); these increases were greater (P < 0.003) than in the placebo group. Oxandrolone increased 1-RM strength for leg press by 6.7 +/- 6.4% (P < 0.001), leg flexion by 7.0 +/- 7.8% (P < 0.001), chest press by 9.3 +/- 6.7% (P < 0.001), and latissimus pull-down exercises by 5.1 +/- 9.1% (P = 0.02); these increases were greater than placebo. Oxandrolone reduced total (-1.9 +/- 1.0 kg) and trunk fat (-1.3 +/- 0.6 kg; P < 0.001), and these decreases were greater (P < 0.001) than placebo. Twelve weeks after oxandrolone was discontinued (week 24), the increments in LBM and muscle strength were no longer different from baseline (P > 0.15). However, the decreases in total and trunk fat were sustained (-1.5 +/- 1.8, P = 0.001 and -1.0 +/- 1.1 kg, P < 0.001, respectively). Thus oxandrolone induced short-term improvements in LBM, muscle area, and strength, while reducing whole body and trunk adiposity. Anabolic improvements were lost 12 wk after discontinuing oxandrolone, whereas improvements in fat mass were largely sustained.