Increase In Isometric Strength Research Articles

WORK OF MUSCLES RESPONSIBLE FOR THE FUNCTIONING OF THE FOOT IN CONDITIONS OF KNEE JOINT CONTRACTURE

Prolonged walking with knee joint contracture causes changes in the functioning of the muscles of the lower leg and foot. Objective. To study the functioning of the foot and leg muscles in the conditions of knee joint contracture using a human walking model. Methods. The gait analysis was performed in the OpenSim 4.0 program. The modeling was based on the gait2394 model. The following muscles were studied: m. peroneus brevis, m. peroneus longus, m. peroneus tertius, m. tibialis posterior, m. tibialis anterium, m. flexor digitorum longus, m. flexor hallucis longus, m. extensor digitorum longus, m. extensor hallucis longus. Results. Restriction of joint mobility leads to a redistribution of muscle strength. In conditions of 15° knee joint flexion contracture, support on the toes causes significant overstrain of the muscles responsible for the functioning of the lower leg, foot and toes. In particular, the m. peroneus brevis and m. peroneus longus are quite long, their function is impaired, but the required increase in strength is from 10 to 400 %, while the m. peroneus tertius (short), for foot flexion in some phases of the step, its strength increased threefold. Among the muscles of the lower leg, the greatest increase in isometric strength was required for the m. tibialis anterior compared to the m. tibialis posterior, which works mainly for foot extension. For the muscles responsible for flexion/extension of the toes in conditions of knee joint contracture, a significant, sometimes 3–5 times, increase in strength was necessary to perform the required function. Conclusions. Knee joint contracture leads to a change in the biomechanics of the entire lower extremity, namely, to an increase in changes in the functioning of the muscles responsible for the functioning of the foot, which work under such conditions with a constant increase in tension. Given the impact of knee joint contracture on the functioning of the muscles of the lower extremity, it is possible to predict the course of thepathological process, determine which muscle groups are most affected and which muscle group needs to be corrected before and after surgery.

The effects of neuromuscular electrical stimulation on strength, pain, and function in individuals with knee osteoarthritis: a systematic review with meta-analysis

ABSTRACT We aimed to investigate the effects of neuromuscular electrical stimulation on muscle strength, pain relief, and improvement in function in patients with knee osteoarthritis. Databases were searched from December 2017 to July 2020 and included PubMed, Embase, LILACS, and the Cochrane Central Register of Controlled Trials. A manual search was also performed by checking the reference lists of eligible articles. The PRISMA guidelines were followed. The studies selected compared NMES with an exercise program on isometric muscle strength as a primary outcome. The secondary outcomes were pain and function. The quality of the studies was assessed using the Risk of Bias assessment and PEDro scale, and the overall quality of the evidence was assessed using the GRADE approach. Eight studies were included in this systematic review. A total of 571 patients were analyzed. Neuromuscular electrical stimulation associated with exercise promoted an increase in isometric strength of the quadriceps muscle compared to the active control group, demonstrating heterogeneity and statistical difference (95% CI=1.16 to 5.10, I2=97%, p=0.002; very low-certainty evidence). NMES associated with exercise did not improve physical function (95% CI=−0.37 to 0.59, I2=0%, p=0.67; low-certainty evidence) and showed controversial results for pain compared to an active control group (qualitative assessment). In conclusion, NMES induces an increase in muscle strength in patients with osteoarthritis compared to an active control group. No differences were found for physical function and pain outcomes. Further research is needed due to the uncertain level of evidence.

Progressive Resistance Exercises plus Manual Therapy Is Effective in Improving Isometric Strength in Overhead Athletes with Shoulder Impingement Syndrome: A Randomized Controlled Trial.

Reduction in isometric strength of the scapulohumeral muscles is a commonly seen impairment in overhead athletes afflicted with shoulder impingement syndrome (SIS). The purpose of this study was to compare the effects of two different treatment programs: progressive resistance exercises plus manual therapy (PRE plus MT) and motor control exercises (MCE), on isometric strength of upper trapezius (UT), middle trapezius (MTr), lower trapezius (LT), serratus anterior (SA), supraspinatus (Supr.), anterior deltoid (A.D), and latissimus dorsi (LD). 80 male university-level overhead athletes clinically diagnosed with SIS were randomly allocated into either of the two groups: PRE plus MT and MCE group. Athletes in the PRE plus MT group underwent graduated exercises with resistance elastic band, stretching exercises, and mobilization of the thoracic and shoulder joints. MCE group was submitted to motor control exercises in varied planar positions. Athletes in both groups underwent management 3 times a week for 8 weeks. Isometric strength of UT, MTr, LT, Supr, A.D, SA, and LD was measured at three-time points: baseline, 4th week, and 8th week. Relative to baseline, both interventions were found to be effective in increasing and optimizing the isometric strength of muscles (p < 0.05) except for supraspinatus in the MCE group (p > 0.05). However, athletes in PRE plus MT group presented a more pronounced increase in isometric strength than those in the MCE group. Between groups analysis found the largest isometric strength improvement in PRE plus MT group for A.D, followed by Supr. and UT muscles (p < 0.05; effect size: 0.39 to 0.40). The study concluded that compared to MCE, PRE plus MT provides greater improvement in the isometric strength of scapulohumeral muscles.

The relationship between range of motion and muscle strength of the shoulder joint in professional baseball pitchers

Background and objective: This study aimed to assess the relationship between range of motion (ROM) and isometric strength of the shoulder joint, adjusted for humeral head retroversion angle (HHRA), in professional baseball pitchers. Material and Methods: A total of 18 pitchers from a professional baseball team were included in this study. The isometric strength of internal rotation (IR) and external rotation (ER) were measured using an isokinetic device at 85◦ and 30◦ ER, and at 25◦ IR. A linear regression analysis was then performed. Results: The HHRA of the dominant arm was approximately 7◦ greater than that of the non-dominant arm (P &lt; 0.001). As the IR ROM increased by 1◦, the IR isometric strength at 25◦ IR was significantly increased by 0.448% body weight (P &lt; 0.05). However, as the ROM of IR increased, the IR isometric strength at 85◦ and 30◦ ER was not significant (P &gt; 0.05), and as the ROM of ER increased, the IR and ER isometric strength were not significant (P &gt; 0.05). Conclusions: Thus, the increase of IR ROM in professional baseball pitchers was associated with an increase in isometric strength at 25◦ IR, after adjustments were made for HHRA.

Low-load blood flow restriction elicits greater concentric strength than non-blood flow restriction resistance training but similar isometric strength and muscle size.

Low-load venous blood flow restriction resistance training (RT + BFR) has been demonstrated to increase muscle strength to a greater degree than low-load non-BFR resistance training (RT) during isotonic training, but no previous investigations have examined RT + BFR versus RT during isokinetic training. The purpose of the present study was to examine the effects of 4 weeks of isokinetic low-load RT + BFR versus low-load RT on indices of muscle strength, muscle size, and neural adaptations. Thirty women (mean ± SD; 22 ± 2years) participated in this investigation and were randomly assigned to 4 weeks of either RT + BFR (n = 10), RT (n = 10), or control (n = 10) group. Resistance training consisted of 75 reciprocal forearm flexion-extension isokinetic muscle actions of the forearm flexors performed at a velocity of 120°s-1. Concentric peak torque increased to a greater extent for RT + BFR after 4 weeks (36.9%) compared to RT (25.8%), but there were similar increases in isometric torque (23.3-42.1%). For both RT + BFR and RT, there were similar increases in muscle cross-sectional area and muscle thickness of the biceps brachii after 2 weeks (11.3-14.3% and 12.4-12.9%, respectively) and 4 weeks (18.7-21.9% and 19.0-20.0%, respectively). There were similar increases in mechanomyographic amplitude, mechanomyographic mean power frequency, and electromyographic mean power frequency, but no changes in electromyographic amplitude for all conditions (including control). These findings indicated that low-load RT + BFR elicited greater increases in concentric strength than low-load RT, but elicited comparable increases in isometric strength and muscle size. There were also no differences in any of the EMG and MMG responses among conditions.

Heavier- and lighter-load isolated lumbar extension resistance training produce similar strength increases, but different perceptual responses, in healthy males and females.

ObjectivesMuscles dominant in type I muscle fibres, such as the lumbar extensors, are often trained using lighter loads and higher repetition ranges. However, literature suggests that similar strength adaptations can be attained by the use of both heavier- (HL) and lighter-load (LL) resistance training across a number of appendicular muscle groups. Furthermore, LL resistance exercise to momentary failure might result in greater discomfort.DesignThe aims of the present study were to compare strength adaptations, as well as perceptual responses of effort (RPE-E) and discomfort (RPE-D), to isolated lumbar extension (ILEX) exercise using HL (80% of maximum voluntary contraction; MVC) and LL (50% MVC) in healthy males and females.MethodsTwenty-six participants (n = 14 males, n = 12 females) were divided in to sex counter-balanced HL (23 ± 5 years; 172.3 ± 9.8 cm; 71.0 ± 13.1 kg) and LL (22 ± 2 years; 175.3 ± 6.3 cm; 72.8 ± 9.5 kg) resistance training groups. All participants performed a single set of dynamic ILEX exercise 1 day/week for 6 weeks using either 80% (HL) or 50% (LL) of their MVC to momentary failure.ResultsAnalyses revealed significant pre- to post-intervention increases in isometric strength for both HL and LL, with no significant between-group differences (p > 0.05). Changes in strength index (area under torque curves) were 2,891 Nm degrees 95% CIs [1,612–4,169] and 2,865 Nm degrees 95% CIs [1,587–4,144] for HL and LL respectively. Changes in MVC were 51.7 Nm 95% CIs [24.4–79.1] and 46.0 Nm 95% CIs [18.6–73.3] for HL and LL respectively. Mean repetitions per set, total training time and discomfort were all significantly higher for LL compared to HL (26 ± 8 vs. 8 ± 3 repetitions, 158.5 ± 47 vs. 50.5 ± 15 s, and 7.8 ± 1.8 vs. 4.8 ± 2.5, respectively; all p < 0.005).ConclusionsThe present study supports that that low-volume, low-frequency ILEX resistance exercise can produce similar strength increases in the lumbar extensors using either HL or LL. As such personal trainers, trainees and strength coaches can consider other factors which might impact acute performance (e.g. effort and discomfort during the exercise). This data might prove beneficial in helping asymptomatic persons reduce the risk of low-back pain, and further research, might consider the use of HL exercise for chronic low-back pain symptomatic persons.

Resistance Training for Professional String Musicians: A Prospective Intervention Study

Many professional musicians report performance- related musculoskeletal disorders (PRMDs). Evidence shows that resistance training programs are preventive for musculoskeletal disorders, but only a few studies have been performed among musicians. The aim of this study was to evaluate whether a functional resistance training program can increase isometric back endurance and isometric strength in the neck, shoulder, and wrist for professional string musicians and affect their perceived performance during instrumental play, as well as their muscle and joint mobility and the occurrence and intensity of pain. 24 professional string musicians from three Swedish symphony orchestras participated in the study, performing individually designed exercise sessions twice a week over an 11-week period. Isometric strength and isometric back endurance were measured pre- and postintervention with a hand-held dynamometer and the Biering-Sorensen test, respectively. A web-based questionnaire was used for assessing perceived performance during instrumental play, as well as mobility and occurrence and intensity of pain. After the training period, the group showed an 11% to 19% increase in isometric strength for neck and upper extremities and 25% improved isometric endurance in back extensors (p<0.05). Moreover, 29% to 59% of the group showed improvements in mobility, performance during instrumental play, and PRMDs, although these improvements did not reach statistical significance. This functional resistance training program seems to be a non-harmful and advantageous exercise method for professional string musicians, but randomized and controlled studies are needed to confirm the results.

The effects of d-aspartic acid supplementation in resistance-trained men over a three month training period: A randomised controlled trial.

ContextResearch on d-aspartic acid (DAA) has demonstrated increases in total testosterone levels in untrained men, however research in resistance-trained men demonstrated no changes, and reductions in testosterone levels. The long-term consequences of DAA in a resistance trained population are currently unknown.ObjectiveTo evaluate the effectiveness of DAA to alter basal testosterone levels over 3 months of resistance training in resistance-trained men.DesignRandomised, double-blind, placebo controlled trial in healthy resistance-trained men, aged 18–36, had been performing regular resistance training exercise for at least 3 d.w-1 for the previous 2 years. Randomised participants were 22 men (d-aspartic acid n = 11; placebo n = 11) (age, 23.8±4.9 y, training age, 3.2±1.5 y).InterventionD-aspartic acid (6 g.d-1, DAA) versus equal-weight, visually-matched placebo (PLA). All participants performed 12 weeks of supervised, periodised resistance training (4 d.w-1), with a program focusing on all muscle groups.MeasuresBasal hormones, total testosterone (TT), free testosterone (FT), estradiol (E2), sex-hormone-binding globulin (SHBG) and albumin (ALB); isometric strength; calf muscle cross-sectional area (CSA); calf muscle thickness; quadriceps muscle CSA; quadriceps muscle thickness; evoked V-wave and H-reflexes, were assessed at weeks zero (T1), after six weeks (T2) and after 12 weeks (T3).ResultsNo change in basal TT or FT were observed after the intervention. DAA supplementation (n = 10) led to a 16%, 95% CI [-27%, -5%] reduction in E2 from T1-T3 (p<0.01). The placebo group (n = 9) demonstrated improvements in spinal responsiveness (gastrocnemius) at the level of the alpha motoneuron. Both groups exhibited increases in isometric strength of the plantar flexors by 17%, 95% CI [7%, 28%] (p<0.05) as well as similar increases in hypertrophy in the quadriceps and calf muscles.ConclusionsThe results of this paper indicate that DAA supplementation is ineffective at changing testosterone levels, or positively affecting training outcomes. Reductions in estradiol and the blunting of peripheral excitability appear unrelated to improvements from resistance training.Trial registrationAustralian New Zealand Clinical Trials Registry ACTRN12617000041358

Adaptations in corticospinal excitability and inhibition are not spatially confined to the agonist muscle following strength training.

We used transcranial magnetic stimulation (TMS) to determine the corticospinal responses from an agonist and synergist muscle following strength training of the right elbow flexors. Motor-evoked potentials were recorded from the biceps brachii and flexor carpi radialis during a submaximal contraction from 20 individuals (10 women, 10 men, aged 18-35years; training group; n=10 and control group; n=10) before and after 3weeks of strength training at 80% of 1-repetition maximum (1-RM). To characterise the input-output properties of the corticospinal tract, stimulus-response curves for corticospinal excitability and inhibition of the right biceps brachii and flexor carpi radialis were constructed and assessed by examining the area under the recruitment curve (AURC). Strength training resulted in a 29% (P<0.001) increase in 1-RM biceps brachii strength and this was accompanied by a 19% increase in isometric strength of the wrist flexors (P=0.001). TMS revealed an increase in corticospinal excitability AURC and a decrease in silent period duration AURC for the biceps brachii and flexor carpi radialis following strength training (all P<0.05). However, the changes in corticospinal function were not associated with increased muscle strength. These findings show that the corticospinal responses to strength training of a proximal upper limb muscle are not spatially restricted, but rather, results in a change in connectivity, among an agonist and a synergistic muscle relevant to force production.

Pressure Pain and Isometric Strength of Neck Flexors Are Related in Chronic Tension-Type Headache

Background: In patients with chronic tension-type headache (CTTH) changes in pressure pain in the cervical region are associated with peripheral or central sensitization. It is hypothesized that an increase of isometric strength of neck flexors would lead to a decrease of pressure pain in CTTH, as an expression of reduced peripheral or central sensitization Objective: In this study we aimed to analyze the correlation between change in isometric strength of the neck flexors and change in pressure pain scores (PPS) in patients with CTTH. Study Design: Comparative analysis of data from previous study. Setting: Primary healthcare center. Methods: Data from 145 patients with CTTH who underwent a manual therapy program including isometric strength training of the neck flexors were analyzed at 8 and 26 weeks posttreatment. PPS were measured as a total of pain scores on a numeric rating scale (score 0 to 10) on application of a pressure stimulus of 3kg/cm at 8 cervical- and suboccipital muscles. Isometric strength of the neck flexors was measured in seconds. Correlations were computed between changes in PPS and isometric neck flexor strength. Results: Isometric strength of neck flexors scored significantly different compared to baseline measurement (mean 30.0 seconds, sd:25.2), and increased with a mean difference of 17.33 seconds (95%CI: 20.61 to 14.05) at 8 weeks and 19.18 seconds (95%CI: 23.48 to 14.87) at 26 weeks. Similarly, compared to PPS baseline measurement (31.6 points, sd:18.6), mean difference in PPS was significantly decreased at 8 and 26 weeks: -11.3 points (95%CI: -8.77 to -13.83) and -11.15 points (95%CI: -8.31 to -13.99). There is a negative correlation between changes in PPS and changes in isometric strength of neck flexors which is weak at 8 weeks (r = -0.243, P = 0.004) and moderate at 26 weeks (r = -0.318, P &lt; 0.000). Limitations: Correlational analysis. Conclusion: Decrease in PPS correlates with increases in isometric strength of neck flexors in patients with CTTH in short- and long-term Key words: Chronic tension-type headache, pressure pain, neck flexors, manual therapy, sensitization, isometric strength, cervical spine

Do kinaesthetic tapes affect plantarflexor muscle performance?

This study aimed to examine the effects of application of kinaesthetic tapes on plantarflexor muscle performance. We hypothesised that taping of the triceps surae muscle would improve plantarflexor muscle strength and endurance with no significant effect on drop jump performance. Using a repeated-measures design, all performance measures were obtained in 24 volunteers on two separate occasions: without tapes and after application of kinaesthetic tapes. Performance tests included measurements of isometric plantarflexor muscle strength and the associated electromyographic activity of the gastrocnemius muscle, an isokinetic fatigue resistance test (30 contractions at 180° · s−1) and assessments of drop jump performance. The taping-intervention was associated with an increase in gastrocnemius electromyographic activity. However, significant increases in isometric strength were only found at fully dorsiflexed ankle positions (+12% at −20°). Strength gains were negatively correlated to baseline strength (r = −.58). The intervention did not affect the results of the isokinetic fatigue and drop jump tests. The application of kinaesthetic tapes over the triceps surae muscle promotes an increase in isometric strength and gastrocnemius muscle activity. Our data suggest that these effects are joint-angle dependent and more prominent in weaker individuals. By contrast, the taping-intervention improves neither drop jump performance nor muscular endurance.

The Effect of a 9 Month Whole Body Vibration Program at Two Different Intensities on Bone Mineral Density in Women

Bone loss resulting in osteoporosis is a major problem for postmenopausal women who have approximately a 50% chance of being diagnosed with this disease. Whole body vibration (WBV) has been used as an alternative mode of exercise to increase muscular strength and bone mineral density (BMD) but research on the intensity of vibration needed is lacking. PURPOSE: To examine the effects of utilizing WBV training at two different intensities on bone mineral density and body composition in women with low BMD. METHODS: The final sample for the study consisted of 27 sedentary women (age: 62.2 ± 6.0 yr, weight: 71.7 ± 12.7 kg, and lean mass: 38.4 ± 4.3 kg). Participants were randomly divided into one of three groups: control (CON; n = 9), low-intensity vibration (LI; n = 13), and high-intensity vibration (HI; n = 5). The two treatment groups participated in a 9-month WBV program 3 times/ wk, with monthly increases in duration and intensity. The control group was instructed to not change their physical activity habits. Bone mineral density and body composition were assessed with DXA (Lunar Prodigy). All participants completed an isometric strength assessment on the Biodex. A 3 x 2 (treatment x time) repeated measures MANOVA was used to analyze the data with level of significance set at.05. RESULTS: No significant changes in BMD or body composition were found for any group. Percent changes in lumbar spine and femoral neck BMD were 4.8% and 3.6% for HI, 0.5% and 1.7% for LI, and 1.5% and 0.4% for CON, respectively. Leg extension strength had a significant 23% increase (p =.012) for the HI group and a significant 11.1% decrease (p =.015) for the CON group while the LI group change (-7.1%) was not significant. Changes in leg flexion strength (18.9%, -6.5%, -5.6%, for HI, LI, and CON respectively) followed a similar pattern but were not significant. CONCLUSION: Based on our findings, WBV did elicit significant increases in isometric strength, but only in the HI group. There were no significant changes in BMD in women with low bone mass, though small sample size could have precluded finding significant differences. Supported by Texas Woman's University Multidisciplinary Research Program.

Physiological Effects of Concurrent Training in Elderly Men

The aim of the present study was to investigate the effects of concurrent strength and endurance training on neuromuscular and hormonal parameters in elderly men. 23 healthy men (65±4 years) were randomly assigned to 1 of 3 groups: concurrent (CG, n=8), strength (SG, n=8) or endurance group (EG, n=7). The programs consisted, of strength training, endurance training on a cycle ergometer or a combination of both in the same session 3 times per week over a duration of 12 weeks. Subjects were evaluated on parameters related to muscle strength, muscle activation and serum hormones. There were significant increases in lower-body strength in all groups (P<0.05), with higher increases in SG (67%) than CG (41%) and both were higher than EG (25%) (p<0.01). Only SG and CG increased upper-body strength (p<0.01), with no significant difference between the 2 groups. Furthermore, there were significant decreases in free testosterone in EG after training. Significant increases in isometric strength and maximal muscle activation (p<0.05) as well as decreases in the submaximal muscle activation to the same load, were only seen in SG (p<0.05). The present results suggest that the interference effect observed due to concurrent strength and endurance training could be related to impairment of neural adaptations.

A comparison of training methods to increase neck muscle strength

Objective: To compare two neck strength training modalities. Background: Neck injury in pilots flying high performance aircraft is a concern in aviation medicine. Strength training may be an effective means to strengthen the neck and decrease injury risk. Methods: The cohort consisted of 32 age-height-weight matched participants, divided into two experimental groups; the Multi-Cervical Unit (MCU) and Thera-Band tubing groups (THER), and a control (CTRL) group. Ten weeks of training were undertaken and pre-and post isometric strength testing for all groups was performed on the MCU. Comparisons between the three groups were made using a Kruskal-Wallis test and effect sizes between the MCU and the THER groups and the THER and CTRL groups were also calculated. Results: The MCU group displayed the greatest increase in isometric strength (flexion 64.4%, extension 62.9%, left lateral flexion 53.3%, right lateral flexion 49.1%) and differences were only statistically significant (p&lt;0.05) when compared to the CTRL group. Increases in neck strength for the THER group were lower than that shown in the MCU group (flexion 42.0%, extension 29.9%, left lateral flexion 26.7%, right lateral flexion 24.1%). Moderate to large effect sizes were found between the MCU and THER as well as the THER and CTRL groups. Conclusions: This study demonstrated that the MCU was the most effective training modality to increase isometric cervical muscle strength. Thera-Band tubing did however, produce moderate gains in isometric neck strength

The effect of short-term strength training on human skeletal muscle: the importance of physiologically elevated hormone levels.

The effect of strength training and endogenously elevated hormone levels (plasma testosterone, growth hormone (GH) and cortisol) was studied in 16 young untrained males, divided into an arm only training group, A, and a leg plus arm training group, LA, in order to increase circulating levels of anabolic hormones. Both groups performed the same one-sided arm training for 9 weeks, twice a week. Group A trained only one arm (AT), the contralateral arm serving as control (AC), whereas group LA additionally trained their legs following the training of the one arm (LAT), with the contralateral arm serving as control (LAC). In spite of the attempt to match the two groups, the initial isometric arm strength was 20-25% lower for group LA compared to group A (significant for the arm to be trained). Isometric strength increased significantly in LAT and LAC by 37% and 10%, respectively, while the 9% and 2% increases in AT and AC, respectively, remained insignificant. Isokinetic strength increased at one out of three velocities tested for the trained arm relative to the untrained arm in both group A and group LA (P<0.05). Functional strength increased significantly by 20% in LAT, 18% in LAC, 19% in AT, and 17% in AC. Hormonal responses were monitored during the first and last training sessions. Resting hormone levels remained unchanged for both groups. However, during the first training session plasma testosterone as well as plasma cortisol increased significantly in group LA but not in group A. Plasma GH rose in all exercise tests, except during the last test in group LA, but was significantly higher in group LA than in group A in the first training session. In conclusion, a larger relative increase in isometric strength was found in the group having the highest hormonal response. However, due to the initial difference in isometric strength caution must be taken with the interpretation of this finding, which may only indicate a possible link between anabolic hormones and muscle strength with training.

EFFECTS OF A LOW INTENSITY WEIGHT TRAINING PROGRAM ON MUSCULAR STRENGTH AND FUNCTIONAL ABILITY IN THE HEALTHY ELDERLY

One of the most pronounced changes associated with increasing age is impairment of movement related to decreased strength and flexibility. This study evaluated the impact of using hand-held and ankle weights with a group of healthy elderly participating in an exercise class called Body Recall. A Body Recall class consists of 60 minutes of group instruction utilizing rhythmic movements in a manner feasible for older individuals. 16 subjects (5 males and 11 females, weight = 68.3 ± 12.6 kgs, age = 68.4 ± 3.2 yrs.) underwent 8 weeks of exercise training incorporating hand-held and ankle weights. Isometric strength was measured with a hand-held dynamometer for shoulder flexion, knee extension, hip flexion, ankle plantar flexion and grip strength. Subjects also underwent a functional ability test designed to simulate grocery shopping consisting of standing from a sitting position, walking 50 feet and returning 50 feet carrying a “bag of groceries”. A significant increase in isometric strength was found for ankle plantar flexion (65.3 ± 10.4 kgs to 69.6 ± 12.2 kgs, p < 0.05, % change = 7%). For the functional simulation, subjects carried significantly more weight after the training (6.5 kgs to 8.5 kgs, p < 0.05) with no significant increase in time to walk the 50 feet distance. RPE for simulated grocery shopping was also significantly lower after training (10.3 to 9.1, p < 0.05). In conclusion, modest weight training increased ankle plantar flexion strength as well as increased the ability to perform a typical activity of daily living such as grocery shopping as indicated in the functional simulation.

Effectiveness of Arthritis Foundation Aquatic Program on Strength and Range of Motion in Women with Arthritis

The purpose of this study was to ascertain the effect of Arthritis Foundation Aquatic Program (AFAP) exercises on strength and range of motion (ROM) measures in women with arthritis. Exercise group (EX) subjects (n = 17) trained three times a week for 6 weeks in AFAP classes. Pre- and posttest isometric strength and ROM tests were conducted on shoulder and hip abduction movements on both limbs. For hip abduction. EX subjects made significant increases in isometric strength and ROM measures ranging from 13.0 to 17.0%. No significant changes in strength or ROM measures for shoulder abduction were found for the EX group. The control group (n = 10) demonstrated no significant changes in isometric or ROM measures for either joint test. The basic 6-week AFAP protocol appears sufficient to induce strength and ROM changes in joints affected by arthritis but may not be sufficient to induce similar changes for joint motions not affected by arthritis.

THE EFFECT OF COMBINED VERSUS ECCENTRIC TRAINING ON MARKERS OF OVERSTRESS298

The main purpose of the study was to determine if the eccentric phase of a squat would induce muscle trauma and subsequent performance decrements in IRM comparable to combined concentric-eccentric training. 28 weight trained subjects were assigned to an eccentric (ECC, n=11) or combined (COM, n=9) training group. ECC lowered the weight from a standing to a parallel position. COM performed both phases of the squat. All performed 13 training sessions (10 sets; 1 rep/set, 100% IRM 2min rest between sets). IRM was assessed on a daily basis. Peak isometric and isokinetic forces were assessed before, mid-, and after training. Muscle biopsies to assess glycogen levels and muscle damage, were performed before and after the training. Profile of Mood States (POMS) were completed every 3d. A repeated measures ANOVA (p<.05) revealed no significant group difference in: IRM squat, glycogen depletion, and POMS. There was a significant decrease in isometric force for COM, and a significant increase for ECC. Z-line streaming, indicative of muscle damage, was seen in ECC. Conclusion: similar physiological and psychological responses were observed between the two training groups. Surprisingly, even though damage was evident in ECC, they demonstrated a significant increase in isometric strength, suggesting that muscle trauma might not be a limiting factor in an increase in isometric force.

Strength, Mobility, Their Changes, and Pain Reduction in Active Functional Restoration for Chronic Low Back Disorders

The association between subjective experience in pain reduction and objective measurements in improvement of physical functioning was analyzed with chronic low back pain (CLBP) patients (n = 143) who attended a 12-week multidimensional back treatment program emphasizing active functional restoration. Low back flexion-extension, lateral flexion and rotation, isometric strength, and mobility and their changes were measured. The results showed that 79% of the subjects reported subjective decrease in LBP during the 12-week restoration program, and simultaneous increases in isometric strength and mobility also were measured in approximately 80% of the subjects. Concordance of these findings was high, i.e., the reduction of pain and improvement of function occurred mostly in the same subjects. However, the correlations between physical functioning parameters and pain reduction were low (rs below 0.22). Baseline strength and mobility values did not differ between those who benefited from the treatment regarding pain and those who did not. Thus, absolute levels at the baseline or magnitude of changes in the measurements of maximum isometric strength or mobility were not associated with pain reduction. The results indicate that subjective pain reduction is significantly associated with improvement per se in trunk muscle function and spinal mobility during active functional restoration, but not with the magnitude of the improvements. This should be considered when designing rehabilitation programs and outcome criteria for rehabilitation.

Strength and Bite, Part I: An Analytical Review

The original clinical observations and research in the area of bite and strength enhancement studied individuals with obvious malocclusion and a subject population with mixed occlusions. An increase in isometric strength was obtained when biting on a K-MORA, an intraoral device that supports a mandibular position determined by a functional criterion. The criterion is a locking response to the Isometric Deltoid Press, a muscle challenge used by kinesiologists. Rather than replication with improved design, subsequent research (1) employed different mandibular positions based on therapeutic, electrical impulse or structural criteria; (2) tested mainly isokinetic strength; (3) referred to "strength" without qualification, implying more generalization than the findings actually allowed; (4) criticized and rejected positive findings by attributing strength increase to the placebo effect even though in no instance has the placebo effect been demonstrated in this field. Considering published and unpublished research on isometric strength and the irrelevance of many studies that found no difference in isokinetic strength, it is concluded that it is most probable that isometric strength is increased by the K-MORA in mixed populations.