Effects of Volume Training on Strength and Endurance of Back Muscles: A Randomized Controlled Trial

Progressive submaximal effort hamstring muscle endurance is reduced after reconstruction of the anterior cruciate ligament

BACKGROUND

Endurance capability in the muscles controlling the knee is poorly understood post anterior cruciate ligament (ACL) reconstruction, despite many sporting activities requiring notable muscle endurance. The hamstring muscles, when active, provide important anatomical support to protect the reconstructed graft. In the absence of good hamstring endurance, fatigue may predispose individuals to re-injury.

OBJECTIVE

To assess whether ACL reconstruction (ACLR) with a hamstring graft leads to reduced hamstring endurance 9-13 months post-surgery.

STUDY DESIGN

A cross-sectional inter-limb comparison study was undertaken with participants 9-13 months after an ACLR with a hamstring graft, and a group of age, sex, and activity-matched controls. There were 22 participants in each group.

METHOD

Submaximal hamstring endurance was measured using a progressive fatigue test on an isokinetic dynamometer at a joint angular velocity of 120°/second. The dependant variable was the maximum number of repetitions performed. Statistical comparisons were made across injured, uninjured and control group limbs.

RESULTS

There was a significant (p < 0.05) deficit in hamstring endurance observed between the injured leg (mean: 111 repetitions, SD 49) and uninjured leg (mean: 136 repetitions, SD 67) of the ACL group, but not between the uninjured and control group legs (mean: 124 repetitions, SD 50).

CONCLUSION

The 18% deficit in submaximal hamstring endurance across the ACL-reconstructed individual's limbs is indicative of a notable loss in muscle performance at 9-13 months post-surgery. These results provide initial evidence for supporting further research examining the inclusion of hamstring endurance training in ACL rehabilitation programmes post-surgery.

Ischemic compression associated with joint mobilization does not promote additional clinical effects in individuals with rotator cuff related shoulder pain: A randomized clinical trial

OBJECTIVE

The objective of this study was to verify which are the additional effects of the ischemic compression (IC) technique associated with joint mobilization techniques on pain, morphological aspects of myofascial trigger points (MTrPs), function, and psychological aspects in individuals with rotator cuff-related shoulder pain (RCRSP).

METHODS

Sixty individuals with RCRSP were randomly allocated intervention sessions the Mobilization Group (MG, n = 20), only joint mobilizations of the shoulder complex; intervention sessions Compression Group (CG, n = 20), with the same mobilizations associated with the IC over MTrPs; and Placebo Group (PG, n = 20), with the same mobilizations associated with placebo of IC. All interventions performed 2 per week, for 6-weeks. Pain was assessed by Visual Analogue Scale and function by the Disabilities of the Arm, Shoulder and Hand questionnaire. The kinesiophobia, pain catastrophizing, perception of improvement, mobility, pain threshold and area the MTrPs were also evaluated at baseline (week-0), after 6-weeks and after 10-weeks.

RESULTS

There were no between-group difference in pain: CG-MG 0.8 (95% CI 0.4 to 1.2), CG-PG 0.5 (95% CI 0.0 to 0.9), MG-PG -0.3 (95% CI -0.8 to 0.1) after 6-weeks and CG-MG 0.1 (95% CI -0.2 to 0.5), CG-PG -0.7 (95% CI -0.9 to -0,4), MG-PG -0,8 (95% CI -1.07 to 0.5) at 10-weeks. Similar effects were observed on function, characteristics of MTrPs and psychological aspects.

CONCLUSION

The IC technique on the MTrPs of the upper trapezius muscle associated with joint mobilization techniques has no additional effect on pain in individuals with RCRSP.

TRIAL REGISTRATION

RBR-44v8y7.

Characteristics and usefulness of trunk muscle endurance tests on the Roman chair in healthy adults

Background

Adequate trunk muscle endurance is considered to be an important indicator of good low back stability; therefore, its assessment is needed when determining an individual's risk for back pain. Optimal tests to assess each trunk muscle group separately are difficult to find. The objective of this study was to verify if two groups of trunk muscle endurance tests (standard and alternative) show comparable results in terms of muscle endurance ratios, holding times and rated perceived effort to perform each test.

Methods

The study was designed as a quasi-experimental repeated-measures design. There was a single group of participants who took part in two different trunk muscle endurance testing. Sixty-eight healthy adult volunteers, aged 20-45 years (31.9 ± 7.2 years), without recent musculoskeletal injury or disorder participated in the study. All participants finished the study. Trunk muscle endurance tests as tested on the Roman chair (B tests) were compared with standard tests as suggested by McGill (A tests). Each group of tests consisted of an endurance test for trunk extensors, trunk flexors, and lateral trunk muscles for left and right side. The order of tests' performances was randomly assigned to each participant, whereby a participant did perform A and B tests in the same order. In each test of A and B the holding time was recorded and a perceived effort in each test performance was also assessed by participants. Post testing performance the four ratios of trunk muscles endurance comparison were calculated for each group of tests to determine if there is a good or poor ratio between muscles. Results of each participant were compared for trunk muscle endurance ratio calculations, holding times and rated perceived effort for A and B tests.

Results

Results showed comparable trunk muscle endurance ratios in the three ratios observed, except for the flexors:extensors ratio (A_FL:EX: 1.2 (IQR: 0.7-1.6) vs. B_FL:EX: 0.6 (IQR: 0.3-0.8); p < 0.001). As compared to A tests, holding times were significantly longer in B tests for the extensors (A_EX: 125.5 s (IQR: 104.8-182.8 s) vs. B_EX: 284.0 s (IQR: 213.0-342.3 s); p < 0.001) and lateral trunk muscles (A_L-LM: 61.0 s (IQR: 48.3-80.8 s) vs. B_L-LM: 131.5 s (IQR: 95.5-158.5 s); A_R-LM: 63.5 s (IQR: 45.8-77.3 s) vs. B_R-LM: 113.0 s (IQR: 86.3-148.8 s); p < 0.001), both were also rated as slightly easier to perform in the extensors (A_RPE-EX: 13 (IQR: 12.0-14.0) vs B_RPE-EX: 11 (IQR: 10.0-13.0); p_RPE-EX < 0.001) and lateral muscles testing (A_RPE-LM: 14.0 (IQR: 12.3-15.8) vs. B_RPE-LM: 13.0 (IQR: 12.0-15.0); p_RPE-LM = 0.001).

Conclusions

A and B tests are comparable in three of four trunk muscle endurance ratios, while longer holding times and lower perceived effort to perform were observed in most of the B tests. The Roman chair tests could be used as an alternative to standard tests.

Lumbar stabilisation exercises versus back endurance-resistance exercise training in athletes with chronic low back pain: protocol of a randomised controlled trial

Background

Chronic low back pain (CLBP) is an important disorder in athletes that may negatively affect their performance in competitions. The literature usually recommends physiotherapy based on exercises for back pain management in athletes. Recent evidence suggests that interventions based on lumbar muscle stabilisation exercises (LMSE) and back endurance-resistance exercises (BERE) may improve back pain and function performance. However, it is still unclear which type of exercise is more effective for the treatment of CLBP in athletes.

Objective

To compare the efficacy of LMSE versus BERE in athletes with CLBP.

Design

The study is a 2-arm, prospectively registered, randomised controlled trial.

Setting

The physical therapy clinical and biomechanics laboratory of the UNOPAR University.

Participants

32 male athletes with CLBP, age between 18 and 40 years old, recruited from the local community.

Intervention

An 8-week intervention programme will be carried out with LMSE s versus BERE.

Measurements

Trunk neuromuscular patterns during balance tasks (unipodal and over a ball) using electromyography and force platform parameters, pain, disability, fear and avoidance will be assessed by a blinded assessor at baseline and at follow-up after 8 weeks of intervention period.

Limitations

The absence of blinding intervention and the exclusion of female athletes, seated sports and swimmers will affect the internal and external validity of the study.

Conclusions

The results of this study will elucidate which of these two interventions promote better results in trunk neuromuscular pattern, back pain and function in male athletes with CLBP.