Progressive resistance strength training and the related injuries in older adults: the susceptibility of the shoulder

Skeletal effects of eccentric strengthening exercise: a scoping review

BACKGROUND

Conventional progressive concentric strengthening exercise (CSE) to improve bone mineral density (BMD) and bone mineral content (BMC) may not be feasible for populations with chronic musculoskeletal and/or metabolic conditions, such as osteoporosis or obesity. Muscle lengthening exercise, also known as an eccentric strengthening exercise (ESE), may have a special utility for those populations due to greater force generation versus CSE. In fact, greater mechanical loading can be induced on bone at lower resistance levels with ESE. However, effects of ESE on BMD and BMC are unclear. Thus, the purpose of this review was to interrogate the effects of ESE on BMD and BMC.

METHODS

A literature review was conducted between January 1995 and April 2022 focusing on randomized controlled trials investigating the effects of ESE on BMD and/or BMC in humans. Terms covering the domains of exercise, bone, and populations were searched on PubMed, CINAHL, and Scopus. The methodological quality of each interventional study was rated using Physiotherapy Evidence Database (PEDro) scale. Cohen's d was calculated to determine the magnitude of the effects of ERE on site-specific outcome measures of BMD and/or BMC.

RESULTS

Out of 1,182 articles initially found, a total of seven full length articles met our inclusion criteria. Of the seven studies, most of the interventions were performed in young (n = 5, PEDro = 5-7) versus middle-aged (n = 1, PEDro = 4) or older (n = 1, PEDro = 6) adults. BMD and BMC generally improved due to ESE; however the effects of ESE on BMD and BMC were non-homogenous. Effect size (d) ranged from 0.10-0.87 in young adults while it was 1.16 in older adults. Effect size (d) could not be calculated for the middle-aged adult study due to critical methodological limitations of the intervention.

CONCLUSIONS

Large variability exists for the effectiveness of ESE on BMD/BMC across the human life spectrum. The benefits of ESE on BMD holds promise but rigorous studies are lacking. Further research is needed to examine if the dose, mode, age, and sex-specificity dictate effects of ESE on BMD/BMC.

Effect of different loads on the shoulder in abduction postures: a finite element analysis

Load can change the mechanical environment of dynamic and static stable structures of the shoulder joint, increase the risk of tissue damage and affect the stability of the shoulder joint, but its biomechanical mechanism is still unclear. Therefore, a finite element model of the shoulder joint was constructed to analyze the mechanical index changes of shoulder joint abduction under different loads. The stress of the articular side on the supraspinatus tendon was higher than that of the capsular side, with a maximum difference of 43% due to the increased load. For the deltoid muscle and glenohumeral ligaments, increases in stress and strain were obvious in the middle and posterior deltoid muscles and inferior glenohumeral ligaments. The above results indicate that load increases the stress difference between the articular side and the capsular side on the supraspinatus tendon and increases the mechanical indices of the middle and posterior deltoid muscles, as well as the inferior glenohumeral ligament. The increased stress and strain in these specific sites can lead to tissue injury and affect the stability of the shoulder joint.

Power Training Prescription in Older Individuals: Is It Safe and Effective to Promote Neuromuscular Functional Improvements?

Muscle power has been reported to be critical in counteracting age-related declines in functional performance. Muscle power output in functional performance exercises can be greatly improved in a short period of time (i.e., ≤ 12 weeks) using specific exercise interventions such as power training (i.e., exercises attempting to move loads ranging from 20 to 70% of 1-repetition maximum as fast as possible during the concentric muscle action, followed by a controlled, slower eccentric muscle action). Despite the widespread evidence on the effectiveness of power training in older adults (~ 300 scientific articles published on this topic in the past 10 years), some scientists do not recommend the use of explosive-type muscular contractions during resistance training (i.e., power training) for the older population; indeed, some international guidelines do not mention this type of exercise for older people. The reasons underlying this absence of mention and recommendation for the use of power training as a fundamental exercise strategy for older people are still not well known. Therefore, we attempted to point out the main issues about safety, feasibility, and effectiveness of muscle power training to promote neuromuscular functional improvements in older people.

Exercise Selection and Common Injuries in Fitness Centers: A Systematic Integrative Review and Practical Recommendations

Weight resistance training (RT) is an essential component of physical conditioning programs to improve the quality of life and physical fitness in different ages and populations. This integrative review aimed to analyze the scientific evidence on the relationship between exercise selection and the appearance of musculoskeletal injuries in physical fitness centers (PFC). The PubMed or Medline, EMBASE or Science Direct, Google Scholar and PEDro databases were selected to examine the available literature using a Boolean algorithm with search terms. The review process was performed using the five-stage approach for an integrative review and it was reported according to the PRISMA in Exercise, Rehabilitation, Sport Medicine and Sports Science (PERSiST) guidelines. A total of 39 peer-reviewed articles (Price index = 71.7%) met the inclusion criteria and evaluated the link between exercise selection and the incidence of injuries in exercisers who regularly attend PFC. Most injuries occur to the shoulders, elbows, vertebrae of the spine, and knees. Although the injury etiologies are multifactorial, the findings of the reviewed articles include the impacts of overuse, short post-exercise recovery periods, poor conditioning in the exercised body areas, frequent use of heavy loads, improper technique in certain exercises, and the abuse of performance- and image-enhancing drugs. Practical recommendations addressed to clinical exercise physiologists, exercise professionals, and health professionals are given in this paper. The exercise selection in RT programs requires professional supervision and adhering to proper lifting techniques and training habits that consider the anatomical and biomechanical patterns of the musculoskeletal structures, as well as genetic, pedagogical, and methodological aspects directly related to the stimulus-response process to mitigate the occurrence of RT-related injuries in PFC.

Examining Muscle Activity Differences During Single and Dual Vector Elastic Resistance Exercises

BACKGROUND

Elastic resistance exercise is a common part of rehabilitation programs. While these exercises are highly prevalent, little information exists on how adding an additional resistance vector with a different direction from the primary vector alters muscle activity of the upper extremity.

PURPOSE

The purpose of this study was to examine the effects of dual vector exercises on torso and upper extremity muscle activity in comparison to traditional single vector techniques.

STUDY DESIGN

Repeated measures design.

METHODS

Sixteen healthy university-aged males completed four common shoulder exercises against elastic resistance (abduction, flexion, internal rotation, external rotation) while using a single or dual elastic vector at a fixed cadence and standardized elastic elongation. Surface electromyography was collected from 16 muscles of the right upper extremity. Mean, peak and integrated activity were extracted from linear enveloped and normalized data and a 2-way repeated measures ANOVA examined differences between conditions.

RESULTS

All independent variables differentially influenced activation. Interactions between single/dual vectors and exercise type affected mean activation in 11/16 muscles, while interactions in peak activation existed in 7/16 muscles. Adding a secondary vector increased activation predominantly in flexion or abduction exercises; little changes existed when adding a second vector in internal and external rotation exercises. The dual vector exercise in abduction significantly increased mean activation in lower trapezius by 25.6 ± 8.11 %MVC and peak activation in supraspinatus by 29.4 ± 5.94 %MVC (p<0.01). Interactions between single/dual vectors and exercise type affected integrated electromyography for most muscles; the majority of these muscles had the highest integrated electromyography in the dual vector abduction condition.

CONCLUSION

Muscle activity often increased with a second resistance vector added; however, the magnitude was exercise-dependent. The majority of these changes existed in the flexion and abduction exercises, with little differences in the internal or external rotation exercises.

LEVEL OF EVIDENCE

3b.

Effect of blood flow restriction during low-intensity resistance training on bone markers and physical functions in postmenopausal women

BACKGROUND

The aim of this study was to investigate the effects of 12-week low intensity resistance training (RT) with blood flow restriction on bone mineral density (BMD), bone turnover markers (BTM), physical functions, and blood lactate concentration in postmenopausal women with osteoporosis or osteopenia.

METHODS

26 study participants (56 ± 1.8yrs, T-score: -2.5 ± 0.7) were randomly assigned into Moderate to High-Intensity RT (MHIRT, n = 7), BFR combined with Low-Intensity RT (LIBFR, n = 7), Low-Intensity RT (LIRT, n = 6), or Control group (CON, n = 6). Exercise group performed leg press, leg extension, biceps curl, and triceps extension 3 times a week for 12 weeks. Training intensity were set at 60% of 1-repetition maximum (1-RM) for MHIRT, and at 30% of 1-RM for LIBFR and LIRT, and reset every 4 weeks for increasing intensity.

RESULTS

Lower, and upper limb 1-RM only increased in MHIRT (65%, p < 0.001), and LIBFR (40%, p < 0.05), while LIRT only showed increment on lower limb 1-RM (28%, p < 0.05). All exercise groups demonstrated significant increment on blood lactate concentration after training session (p < 0.001). However, LIBFR showed 2.7 folds higher increment than LIRT (p < 0.001). Although no changes were observed in MHIRT, LIBFR, and LIRT, CON showed significant decrease in BMD (p < 0.05). While, LIRT showed no responses on BTM, LIBFR significantly increased bone formation markers (P1NP) about 7.05 ng/ml (p < 0.05). Lastly, balance improvement was only found in MHIRT, and LIBFR (p < 0.05).

CONCLUSION

12-week LIBFR can be implied as a safe, and effective method to improve muscle strength, P1NP, and balance similar to MHIRT in postmenopausal women with osteoporosis or osteopenia.

Proximal Upper Limb Sensorimotor Integration in Response to Novel Motor Skill Acquisition

Previous studies have shown significant changes in cortical and subcortical evoked potential activity levels in response to motor training with the distal upper-limb muscles. However, no studies to date have assessed the neurological processing changes in somatosensory evoked potentials (SEPs) associated with motor training whole-arm movements utilizing proximal upper-limb muscles. The proximal upper-limb muscles are a common source of work-related injuries, due to repetitive glenohumeral movements. Measuring neurophysiological changes following performance of a proximal motor task provide insight into potential neurophysiological changes associated with occupational postures and movements involving proximal upper limb muscles. This study sought to assess the impact of a novel motor skill acquisition task on neural processing of the proximal upper-limb muscle groups, through the measurement of short-latency median nerve SEPs. One group of 12 participants completed a novel motor training task, consisting of tracing a sinusoidal waveform varying in amplitude and frequency. Baseline SEP measurements were recorded from each participant, followed by a mental recitation control task. Pre-test SEP measurements were then recorded, followed by the motor training task, and post-test SEP recordings. The participants completed the tracing with their right thumb, using glenohumeral rotation only to move their hand. Significant improvements in task accuracy were demonstrated, indicating that motor acquisition had occurred. Significant changes were also seen in the N11, N13, N20, N24, P25, and the N30 SEP peaks were seen following the motor training task. Conclusion: Early SEPs appear to be a sensitive measure of changes in sensorimotor integration in response to novel motor skill acquisition within the proximal upper-limb muscles.

Resistance Training for Older Adults: Position Statement From the National Strength and Conditioning Association

Fragala, MS, Cadore, EL, Dorgo, S, Izquierdo, M, Kraemer, WJ, Peterson, MD, and Ryan, ED. Resistance training for older adults: position statement from the national strength and conditioning association. J Strength Cond Res 33(8): 2019-2052, 2019-Aging, even in the absence of chronic disease, is associated with a variety of biological changes that can contribute to decreases in skeletal muscle mass, strength, and function. Such losses decrease physiologic resilience and increase vulnerability to catastrophic events. As such, strategies for both prevention and treatment are necessary for the health and well-being of older adults. The purpose of this Position Statement is to provide an overview of the current and relevant literature and provide evidence-based recommendations for resistance training for older adults. As presented in this Position Statement, current research has demonstrated that countering muscle disuse through resistance training is a powerful intervention to combat the loss of muscle strength and muscle mass, physiological vulnerability, and their debilitating consequences on physical functioning, mobility, independence, chronic disease management, psychological well-being, quality of life, and healthy life expectancy. This Position Statement provides evidence to support recommendations for successful resistance training in older adults related to 4 parts: (a) program design variables, (b) physiological adaptations, (c) functional benefits, and (d) considerations for frailty, sarcopenia, and other chronic conditions. The goal of this Position Statement is to a) help foster a more unified and holistic approach to resistance training for older adults, b) promote the health and functional benefits of resistance training for older adults, and c) prevent or minimize fears and other barriers to implementation of resistance training programs for older adults.

Tai Chi Combined With Resistance Training for Adults Aged 50 Years and Older: A Systematic Review

BACKGROUND AND PURPOSE

Despite Tai Chi and resistance training being recommended as suitable exercise for older adults, there are no systematic reviews synthesizing the effectiveness of a combination of Tai Chi and resistance training on health promotion of older adults. This study aimed to review the existing literature regarding the effect of Tai Chi and resistance training on physical health, mental health, pain, health-related quality of life, and age-related impairment in adults aged 50 years and older.

METHODS

A systematic review was conducted to report the health outcomes of Tai Chi combined with resistance training research in adults aged 50 years and older. Articles were identified by searching PubMed, Scopus, Web of Science, CINAHL, MEDLINE, Physiotherapy Evidence Database (PEDro), and the Cochrane library using search terms representing "Tai Chi" and "resistance" and "older adults." Quantitative experimental studies with participants aged 50 years and older, where one of the interventions was Tai Chi and resistance training, were included.

RESULTS AND DISCUSSION

The literature search yielded 648 articles from which 7 met the inclusion criteria. Collectively, the studies involved 703 participants aged 50 years and older, including healthy older adults, older adults with history of falls, postmenopausal women, and people diagnosed with end-stage hip osteoarthritis. Studies included different Tai Chi forms in combination with various types of resistance training. Training sessions were 2 to 7.5 h/wk and lasted between 12 weeks and 12 months. After long-term Tai Chi and resistance training, the participants showed significant improvement in upper and lower extremity muscle strength, aerobic endurance, balance, and mobility. However, 1 study failed to show improvement in Functional Movement Screening compared with traditional Tai Chi and nonexercise groups. No study examined the effects of Tai Chi and resistance training on health-related quality of life, fear of falling, or mental health in adults aged 50 years and older.

CONCLUSIONS

The review supports that Tai Chi in combination with resistance training improves physical function and muscle strength in adults aged 50 years and older.

Effects of age and sex on shoulder biomechanics and relative effort during functional tasks

Age-related decline in muscle strength can compromise shoulder function, which could increase the effort needed to perform activities of daily living (ADLs). The purpose of this cross-sectional study was to determine for the first time the relative shoulder effort during ADLs in healthy young and older adults. Ten healthy young adults and ten healthy older adults were tested for maximal isokinetic torque and on a set of ADL tasks. Using inverse dynamics, the shoulder torques during ADLs were referenced to the maximal isokinetic torque and relative effort was determined. Older compared to younger adults had >40% lower isokinetic shoulder abduction strength. The ratio of peak joint torque during six ADLs over the maximal isokinetic torque, i.e., relative effort, was higher in old (∼52%) compared with young adults (∼22%, p < 0.05). Relative effort in older adults was over 40% in overhead activities and particularly high in abduction and reaching tasks, over 60%. Healthy older compared with younger adults perform most ADL tasks involving the shoulder joint with nearly twice the level of relative effort. The concomitant reductions in maximal shoulder isokinetic torque and increases in relative effort may be related to the high prevalence of musculoskeletal pain and shoulder dysfunction in old age reported in epidemiological studies.

Effects of physical, virtual reality-based, and brain exercise on physical, cognition, and preference in older persons: a randomized controlled trial

Background

Physical exercise (PE), virtual reality-based exercise (VRE), and brain exercise (BE) can influence physical and cognitive conditions in older persons. However, it is not known which of the three types of exercises provide the best effects on physical and cognitive status, and which exercise is preferred by older persons. This study compared the effects of PE, VRE, and BE on balance, muscle strength, cognition, and fall concern. In addition, exercise effort perception and contentment in older persons was evaluated.

Methods

Eighty-four older persons (n = 84) were randomly selected for PE, VRE, BE, and control groups. The exercise groups received 8-week training, whereas the control group did not. Balance was assessed by Berg Balance Scale (BBS) and Timed Up and Go test (TUG), muscle strength by 5 Times Sit to Stand (5TSTS) and left and right hand grip strength (HGS), cognition by Montreal Cognitive Assessment (MoCA) and Timed Up and Go test Cognition (TUG-cog), fall concern by Fall Efficacy Scale International (FES-I), exercise effort perception by Borg category ratio scale (Borg CR-10), and exercise contentment by a questionnaire.

Results

After exercise, PE significantly enhanced TUG and 5TSTS to a greater extent than VRE (TUG; p = 0.004, 5TSTS; p = 0.027) and BE (TUG; p = 0,012, 5TSTS; p < 0.001). VRE significantly improved MoCA (p < 0.001) and FES-I (p = 0.036) compared to PE, and 5TSTS (p < 0.001) and FES-I (p = 0.011) were improved relative to BE. MoCA was significantly enhanced by BE compared to PE (p < 0.001) and both MoCA and TUG-cog were improved compared to VRE (p = 0.04). PE and VRE significantly (p < 0.001) increased Borg CR-10 in all exercise sessions, whereas BE showed a significant improvement (p < 0.001) in the first 4 sessions. Participants had a significantly greater satisfaction with BE than controls (p = 0.006), and enjoyed VRE and BE more than PE (p < 0.001). Subjects in all exercise groups exhibited benefits compared to the control group (p < 0.001).

Conclusions

PE provided the best results in physical tests, VRE produced measurable improvements in physical and cognition scores, while BE enhanced cognition ability in older persons. Older persons preferred VRE and BE compared to PE. Both exercises are suggested to older persons to improve physical and cognitive conditions.

Six weeks of Mat Pilates training are enough to improve functional capacity in elderly women

The aim of the study was to evaluate the effect of Mat Pilates on the functional capacity (FC) of elderly women before and after six weeks of intervention. Eighteen women aged 62.28 (±2.34) participated in the study. Timed Up and Go test, Timed Up Stairs, Timed Down Stairs, 30-s Chair Stand, Chair Sit-and-Reach and Back Scratch tests were assessed. The results showed significant improvements in all FC tests after six weeks of the Mat Pilates intervention. Summarizing, only six weeks of Mat Pilates training of 60 min per session, three times a week, three series beginning with six repetitions and eight repetitions at the last two weeks of intervention, were enough to improve FC in elderly women. Furthermore, the exercises difficulty increased from beginners to intermediate.

Effects of elastic band resistance training and nutritional supplementation on physical performance of institutionalised elderly--A randomized controlled trial

OBJECTIVES

To evaluate the effects of elastic band resistance training in combination with nutrient supplementation on muscular strength and the ability to perform mobility-related activities of daily living in older adults living in retirement care facilities.

DESIGN

Randomized controlled trial, with a 6-month intervention period.

SETTING

A retirement care facility, Vienna, Austria.

PARTICIPANTS

One hundred and seventeen older adults (14 males (12%) and 103 females (88%)), aged 65 to 97 years (mean age: 82.8 ± 6.0), having a mini-mental state examination score ≥ 23 and no chronic diseases posing a medical contraindication to training therapy.

INTERVENTION

Participants were randomly assigned, but stratified by sex, to one of three intervention groups: supervised resistance exercise training (RT), RT in combination with nutrient supplementation (RTS), or cognitive training group (CT). All interventions were performed two times a week for 6 months. RT was designed to train all major muscle groups using elastic bands. The nutrient supplement (rich in proteins, vitamin D, B2, B12) was distributed every morning as well as after each RT session.

MEASUREMENTS

A battery of motor ability tests and functional test were performed prior to as well as following 3 months and finally after 6 months of intervention. These tests included isokinetic torque measurements of the knee extensors and flexors in concentric mode at 60 and 120°/s, isometric handgrip strength, senior arm-lifting test, chair stand test, maximum walking speed and a 6-minute walking test (6 MWT).

RESULTS

A repeated-measures ANOVA analysis revealed significant improvements in physical function of lower (p=0.002) and upper extremities (p=0.006) for RT and/or RTS in comparison to CT. For isokinetic measurements, 6 MWT, and gait speed time effects (p<0.05) were detected without any group × time interaction effects. Dropouts showed lower performance in chair stand test (p=0.012), 6 MWT (p=0.003), and gait speed (p=0.013) at baseline than that of the finishers of the study.

CONCLUSION

Six months of a low intensity resistance exercise using elastic bands and own body weight is safe and beneficial in improving functional performance of institutionalised older people. Multinutrient supplementation did not offer additional benefits to the effects of RT in improving muscular performance.

The effect of whole body vibration exposure on balance and functional mobility in older adults: a systematic review and meta-analysis

The aim of this review was to systematically evaluate the effect of WBV exposure alone on balance and functional mobility in older adults. A literature search of randomized controlled trials (RCT) reporting the effects of WBV on balance or functional mobility outcomes in older adults, was conducted using multiple databases. WBV-plus-exercise was only included if the control group performed the same exercises as the WBV group, but without vibration. The methodological quality of studies was assessed using the PEDro scale. Meta-analysis was performed if three or more studies measured the same outcome. Twenty RCTs met the inclusion criteria. Eight RCTs compared WBV-only with control and eight RCTs compared WBV-plus-exercise with the same-exercise only group. Meta-analysis indicated that WBV improved single-leg stance (p=0.05) and timed up and go (p=0.004) measures compared with controls. WBV improved other balance and mobility outcomes with inconsistent results. Although balance and mobility appeared to be responsive to WBV-plus-exercise, particularly in lower-functioning patients, compared with WBV-only, caution is required when interpreting the findings. Although there is some evidence for an overall effect of WBV on selected balance and mobility measures, its impact remains inconclusive. Robust RCTs examining WBV-only exposure on balance and functional mobility in older adults are warranted.