The Impact of a Signalized Crosswalk on Traffic Speed and Street-Crossing Behaviors of Residents in an Underserved Neighborhood

Infrastructure improvements such as pedestrian crosswalks that calm traffic and increase access to physical activity opportunities could alleviate important barriers to active living in underserved communities with outdated built environments. The purpose of this study was to explore how the built environment influences street-crossing behaviors and traffic speeds in a low-income neighborhood with barriers to active living in Columbia, Missouri. In 2013, a signalized pedestrian crosswalk and 400-ft-long median was constructed along a busy 5-lane, high-speed arterial highway linking low-income housing with a park and downtown areas. Data collection occurred prior to June 2012, and after June 2013, completion of the project at the intervention site and control site. Direct observation of street-crossing behaviors was performed at designated intersections/crosswalks or non-designated crossing points. Traffic volume and speed were captured using embedded magnetic traffic detectors. At the intervention site, designated crossings increased at the new crosswalk (p < 0.001), but not at non-designated crossings (p = 0.52) or designated crossings at intersections (p = 0.41). At the control site, there was no change in designated crossings (p = 0.94) or non-designated crossings (p = 0.79). Motor vehicles traveling above the speed limit of 35 mph decreased from 62,056 (46 %) to 46,256 (35 %) (p < 0.001) at the intervention site and increased from 57,891 (49 %) to 65,725 (59 %) (p < 0.001) at the control site. The installation of a signalized crosswalk facilitated an increase in safe street crossings and calmed traffic volume and speed in an underserved neighborhood. We believe these findings have significant public health implications that could be critical to advocacy efforts to improve infrastructure projects in similar communities.

High-speed power training in older adults: a shift of the external resistance at which peak power is produced

Studies have shown that power training increases peak power (PP) in older adults. Evaluating the external resistance (% 1 repetition maximum [1RM]) at which PP is developed is critical given that changes in the components of PP (force and velocity) are dependent on the %1RM at which PP occurs. The purpose of this study was to compare the changes in PP (and the external resistance at which PP occurred) after 12 weeks of high-speed power training (HSPT) vs. traditional slow-speed strength training (SSST). Seventy-two older men and women were randomized to HSPT at 40% of the 1RM (HSPT: n = 24 [70.8 ± 6.8 years]); traditional resistance training at 80% 1RM (SSST: n = 22 [68.6 ± 7.8 years]); or control (CON: n = 18 [71.5 ± 6.1 years]). Measures of muscle performance were obtained at baseline and after the 12-week training intervention. Changes in muscle power and 1RM strength improved similarly with both HSPT and SSST, but HSPT shifted the external resistance at which PP was produced to a lower external resistance (from 67% 1RM to 52% 1RM) compared with SSST (from 65% 1RM to 62% 1RM) (p ≤ 0.05), thus increasing the velocity component of PP (change: HSPT = 0.18 ± 0.21 m·s; SSST = -0.03 ± 0.15 m·s) (p ≤ 0.05). Because sufficient speed of the lower limb is necessary for functional tasks related to safety (crossing a busy intersection, fall prevention), HSPT should be implemented in older adults to improve power at lower external resistances, thus increasing the velocity component of power and making older adults safer in their environment. These data provide clinicians with the necessary information to tailor exercise programs to the individual needs of the older adult, affecting the components of power.

The effect of fasting on indicators of muscle damage

Many studies have tested the consumption of foods and supplements to reduce exercise-induced muscle damage, but fasting itself is also worthy of investigation due to reports of beneficial effects of caloric restriction and/or intermittent fasting on inflammation and oxidative stress. This preliminary investigation compared indicators of exercise-induced muscle damage between upper-body untrained participants (N=29, 22yrs old (SD=3.34), 12 women) who completed 8h water-only fasts or ate a controlled diet in the 8h prior to five consecutive laboratory sessions. All sessions were conducted in the afternoon hours (i.e., post meridiem) and the women completed the first session while in the follicular phase of their menstrual cycles. Measures of muscle pain, resting elbow extension, upper arm girth, isometric strength, myoglobin (Mb), total nitric oxide (NO), interleukin 1beta (IL1b), and tumor necrosis factor alpha (TNFa) were collected before and after eccentric contractions of the non-dominant elbow flexors were completed. The fasting group's loss of elbow extension was less than the post-prandial group (p<.05, eta(2)=.10), but the groups did not change differently across time for any other outcome measures. However, significantly higher NO (p<.05, eta(2)=.22) and lower TNFa (p<.001, eta(2)=.53) were detected in the fasting group than the post-prandial group regardless of time. These results suggest intermittent fasting does not robustly inhibit the signs and symptoms of exercise-induced muscle damage, but such fasting may generally affect common indirect markers of muscle damage.

Rehabilitation of a surgically repaired rupture of the distal biceps tendon in an active middle aged male: a case report

BACKGROUND

Complete rupture of the distal tendon of the biceps brachii is relatively rare and there is little information to guide therapists in rehabilitation after this injury. The purposes of this case report are to review the rehabilitation concepts used for treating such an injury, and discuss how to modify exercises during rehabilitation based on patient progression while adhering to physician recommended guidelines and standard treatment protocols.

CASE PRESENTATION

The patient was an active 38-year old male experienced in weight-training. He presented with a surgically repaired right distal biceps tendon following an accident on a trampoline adapted with a bungee suspension harness. The intervention focused on restoring range of motion and strengthening of the supporting muscles of the upper extremity without placing undue stress on the biceps brachii.

OUTCOMES

The patient was able to progress from a moderate restriction in ROM to full AROM two weeks ahead of the physician's post-operative orders and initiate a re-strengthening protocol by the eighth week of rehabilitation. At the eighth post-operative week the patient reported no deficits in functional abilities throughout his normal daily activities with his affected upper extremity.

DISCUSSION

The results of this case report strengthen current knowledge regarding physical therapy treatment for a distal biceps tendon repair while at the same time providing new insights for future protocol considerations in active individuals. Most current protocols do not advocate aggressive stretching, AROM, or strengthening of a surgically repaired biceps tendon early in the rehabilitation process due to the fear of a re-rupture. In the opinion of the authors, if full AROM can be achieved before the 6(th) week of rehabilitation, initiating a slow transition into light strengthening of the biceps brachii may be possible.

LEVEL OF EVIDENCE

4-Single Case report.

An evidence-based recommendation for the inclusion of specific local intrinsic factors in the study of knee osteoarthritis

OBJECTIVE

Adequate characterization of the mechanical environment of the knee with osteoarthritis (OA) is important. These local intrinsic factors are difficult to measure and there is little evidence to guide their selection. This study makes an evidence-based recommendation for the inclusion of specific factors in the future study of knee OA.

METHOD

Forty-six subjects with knee OA were examined. Observed function was measured by the Timed Chair Rise (TCR). Self-reported function was measured by the WOMAC Function Scale and pain was measured by the WOMAC Pain Scale. Local intrinsic factors measured included varus/valgus alignment, anterior/posterior (A/P) laxity, proprioception, isometric knee extension (KE) strength, isometric knee flexion (KF) strength, and knee range of motion (ROM).

RESULTS

Factors were recommended for inclusion in future research if they were significantly correlated with at least one measure of function or pain and if the factor made a significant unique contribution to a regression model when more than one local intrinsic factor was correlated with the same measure of function or pain. Alignment was correlated with pain (r=0.48, p=0.001) and WOMAC function (r=0.38, p=0.009). A/P laxity was correlated with pain (r=0.30, p=0.04) and WOMAC function (r=0.37, p=0.01). Knee ROM was correlated to WOMAC function (r=-0.35, p=0.02). KE strength was correlated with TCR (r=0.32, p=0.03). Alignment made a significant contribution to prediction of pain (p=0.003). A/P laxity (p=0.004) and ROM (p=0.008) made a significant contribution to WOMAC function.

CONCLUSION

We recommend future knee OA studies include the variables varus/valgus alignment, A/P laxity, ROM, and KE strength.

Bike, walk, and wheel: a way of life in Columbia, Missouri, revisited

BACKGROUND

In 2003, Columbia MO was the recipient of a Robert Wood Johnson Foundation (RWJF) Active Living by Design (ALbD) grant to foster active living in the community through behavioral (social marketing, education) and environmental change (improved street design standards, sidewalks around schools, activity-friendly infrastructure) strategies.

PURPOSE

To examine the extent to which the ALbD intervention was associated with increased active living in children and adults community-wide.

METHODS

Seasonal pedestrian and bicyclist counts were performed quarterly in January, April, July, and October at four intersections in downtown Columbia from 2007 to 2009.

RESULTS

Pedestrian counts increased significantly during July 2009 and October 2009 compared to 2007 and 2008, whereas cyclist counts increased significantly during only July 2009 compared to 2007 and 2008.

CONCLUSIONS

The ALbD intervention in Columbia was associated with modest increases in active living in the community, and continued evaluation of these behavior patterns is warranted. The combination of multiple strategies (social marketing, local programming, and infrastructure changes) may be a critical factor in improving active living in communities.

A Walking School Bus program: impact on physical activity in elementary school children in Columbia, Missouri

BACKGROUND

The Robert Wood Johnson Foundation (RWJF) provided Columbia MO with an Active Living by Design (ALbD) grant in 2003 to promote active living in the community. A separate project was funded in 2006 through RWJF's Active Living Research program.

PURPOSE

To evaluate whether participation in a Walking School Bus (WSB) program increased or decreased active living in elementary school children residing in Columbia, in association with ALbD funding.

METHODS

Objective measures of physical activity obtained using accelerometers were collected over 7 days in children participating in a WSB program and children in a nonparticipating comparison group. Differences in the percentage of time spent in moderate- to vigorous-intensity exercise (%MVPA) were compared between groups.

RESULTS

Children in WSB programs showed no differences in %MVPA compared to children not participating in the WSB; however, when comparing the relationship of %MVPA and age, the slope of the regression line was steeper for those children not participating in the WSB.

CONCLUSIONS

The ALbD intervention in Columbia did not result in measurable changes in physical activity in children participating in the Walking School Bus program, but there was a negative association between age and physical activity, and the slope of that regression line was affected by participation in the program.

Effects of high-speed power training on muscle performance and braking speed in older adults

We examined whether high-speed power training (HSPT) improved muscle performance and braking speed using a driving simulator. 72 older adults (22 m, 50 f; age = 70.6 ± 7.3 yrs) were randomized to HSPT at 40% one-repetition maximum (1RM) (HSPT: n = 25; 3 sets of 12-14 repetitions), slow-speed strength training at 80%1RM (SSST: n = 25; 3 sets of 8-10 repetitions), or control (CON: n = 22; stretching) 3 times/week for 12 weeks. Leg press and knee extension peak power, peak power velocity, peak power force/torque, and braking speed were obtained at baseline and 12 weeks. HSPT increased peak power and peak power velocity across a range of external resistances (40-90% 1RM; P < 0.05) and improved braking speed (P < 0.05). Work was similar between groups, but perceived exertion was lower in HSPT (P < 0.05). Thus, the less strenuous HSPT exerted a broader training effect and improved braking speed compared to SSST.

High velocity power training in older adults

Increases in both the age and the number of older adults in the United States will likely result in more people living with functional limitations and physical disabilities. The impact of this change in demographics will not only significantly impact older adult quality of life but may overwhelm existing health care services for this population. Resistance training with a strengthening component is currently recommended for older adults who wish to increase strength and overall health. However, muscle power has recently been found to contribute more to improvement in physical functioning than muscle strength and is becoming a focus of many resistance training studies in older adults. This review will discuss the current research supporting the implementation of traditional strength-enhancing resistance training, examine the contribution of muscle power to function, explore the rationale for implementing high velocity power training interventions, and review the recent literature on these novel power training interventions in older men and women. Recommendations for future research will be discussed.

Bike, walk, and wheel: a way of life in Columbia, Missouri

BACKGROUND

With funding support from the Robert Wood Johnson Foundation, the Active Living Partnership of Columbia, Missouri, sought to make routine physical activity more commonplace in the community through behavioral and environmental change strategies.

INTERVENTION

The Active Living by Design 5P model (partnerships, promotions, programs, policy changes, and physical projects) was modified to create two mutually reinforcing components. Programs and promotions (e.g., Walking School Bus) were implemented to influence individual behaviors and generate public policy advocates. Policy changes, such as activity-friendly street design standards, created safe and attractive places for physical activity programs. A strong, diverse community partnership supported all efforts.

RESULTS

Key project successes were a citywide social marketing program; the Walking School Bus program, which grew rapidly; and policy campaigns resulting in improved street design standards and a voter-approved $3.5 million sales tax for sidewalks around schools. Notable challenges included programs targeting teenagers and efforts to increase physical activity through self-reported activity logging.

LESSONS LEARNED

The most important lesson was to implement multiple strategies because programs can leverage policy successes, and new policies often lead to more funding for infrastructure. Other lessons learned were to build early successes by reaching first for the "low-hanging fruit" (e.g., elementary-age children rather than teenagers) and to have a flexible plan to take advantage of unexpected opportunities (e.g., a new, influential partner with a specific interest).

CONCLUSIONS

A modified 5P model was tested and found to be an effective framework for achieving behavioral and environmental changes that promote healthy, active lifestyles in the community.

The effect of a high-intensity interval training program on high-density lipoprotein cholesterol in young men

This study examined the impact of an 8-week program of high-intensity interval training on high-density lipoprotein cholesterol (HDL-C), total cholesterol (TC), and the atherogenic index (TC/HDL-C) in 36 untrained men ages 21-36 years. Participants were randomly assigned to an interval training group (n = 20) or a control group (n = 16). Participants in the experimental group performed 3.2 km of interval running (1:1 work:rest ratio) 3 times a week for 8 weeks at an intensity of 90% of maximal heart rate ( approximately 423 kcal per session). Results indicated significant pre- to posttraining changes in HDL-C (1.1 vs. 1.3 mmolxL, p < 0.0001) and TC/HDL-C (3.8 vs. 3.1, p < 0.0001) but no significant changes in TC (3.9 vs. 3.8 mmolxL, p > 0.05) with interval training. It was concluded that an 8-week program of high-intensity interval training is effective in eliciting favorable changes in HDL-C and TC/HDL-C but not TC in young adult men with normal TC levels. Our findings support the recommendations of high-intensity interval training as an alternative mode of exercise to improve blood lipid profiles for individuals with acceptable physical fitness levels.

Accuracy of a non-radiographic method of measuring varus/valgus alignment in knees with osteoarthritis

Knee alignment has been shown to affect incidence, progression and treatment of knee osteoarthritis (OA). The gold standard for measuring alignment is a radiograph that is often difficult to obtain. This study demonstrates that a clinical non-radiographic measure can serve as a surrogate assessment of knee alignment in older adults with knee OA. We believe these findings will allow more widespread evaluation of one critical mechanical factor essential to the study of knee OA.

Robotic gait-assisted therapy in patients with neurological injury

Robotic gait training in the treatment of mobility deficits resulting from cerebral vascular injury is gaining popularity in U.S. hospitals and rehabilitation facilities. Advantages of robotic training include patient safety, early mobility training, increased training time per session and reduced physical burden to the therapist. Disadvantages include limited variance of movement and reduced interaction between patient and therapist. Although research has demonstrated positive effects of these devices on mobility improvements, future research with larger patient populations is warranted.

High-speed power training: a novel approach to resistance training in older men and women. A brief review and pilot study

Over the past century, increases in both longevity and the number of older adults in the U.S.A. have given rise to greater numbers of functionally limited and disabled older adults. This has resulted in a decline in the quality of life of our elderly population, as well as an increased burden on our health care system. Resistance training (RT) with a strengthening component has traditionally been recommended to improve health and physical functioning in older adults. Muscle power (force x velocity), or the ability to produce force rapidly, has recently emerged as an important predictor of functioning in older men and women and has been the current focus of many RT studies. In this review, the physiological changes that contribute to the declines in muscle strength and power with aging will first be examined, followed by a discussion of the prevailing theories behind the use of traditional RT in older men and women. The rationale for high-velocity RT will then be explored, and the recent literature on novel training interventions designed to improve muscle power in older adults will be discussed. Finally, some preliminary evidence demonstrating the benefits of high-velocity power training in older men and women will be presented.

Muscle impairments and behavioral factors mediate functional limitations and disability following stroke

BACKGROUND AND PURPOSE

Stroke remains the leading cause of disability in the United States. The purposes of this study were to examine whether quantitative measures of muscle strength and power in the involved lower extremity predict functional limitations and to evaluate the contributions of behavioral factors to mediating disability and quality of life in people who have survived a stroke.

SUBJECTS AND METHODS

A cross-sectional study design was used, and measurements of muscle impairment, lower-body function, disability, quality of life, and behavioral factors were obtained for 31 community-dwelling volunteers who had experienced a single ischemic stroke in the past 6 to 24 months.

RESULTS

Stepwise regression models including impairment and behavioral measures were strong predictors of function, disability, and quality of life. Involved-extremity muscle strength and power and self-efficacy were independently associated with function, whereas depression and self-efficacy were strong predictors of disability and quality of life.

DISCUSSION AND CONCLUSION

The findings warrant future studies to determine whether interventions that address muscle strength and power, depressive symptoms, and low self-efficacy effectively improve function, reduce disability, and enhance quality of life in people who have survived a stroke.

Efficacy of a tart cherry juice blend in preventing the symptoms of muscle damage

BACKGROUND

Numerous antioxidant and anti-inflammatory agents have been identified in tart cherries.

OBJECTIVE

To test the efficacy of a tart cherry juice blend in preventing the symptoms of exercise induced muscle damage.

METHODS

This was a randomised, placebo controlled, crossover design. Fourteen male college students drank 12 fl oz of a cherry juice blend or a placebo twice a day for eight consecutive days. A bout of eccentric elbow flexion contractions (2 x 20 maximum contractions) was performed on the fourth day of supplementation. Isometric elbow flexion strength, pain, muscle tenderness, and relaxed elbow angle were recorded before and for four days after the eccentric exercise. The protocol was repeated two weeks later with subjects who took the placebo initially, now taking the cherry juice (and vice versa). The opposite arm performed the eccentric exercise for the second bout to avoid the repeated bout protective effect.

RESULTS

Strength loss and pain were significantly less in the cherry juice trial versus placebo (time by treatment: strength p<0.0001, pain p = 0.017). Relaxed elbow angle (time by treatment p = 0.85) and muscle tenderness (time by treatment p = 0.81) were not different between trials.

CONCLUSIONS

These data show efficacy for this cherry juice in decreasing some of the symptoms of exercise induced muscle damage. Most notably, strength loss averaged over the four days after eccentric exercise was 22% with the placebo but only 4% with the cherry juice.

Concordance and discordance between two measures of lower extremity function: 400 meter self-paced walk and SPPB

BACKGROUND AND AIMS

The purpose of the study was to assess the concurrent validity of the 400 meter self-paced walk test (400-m W) against the commonly used short physical performance battery (SPPB). A secondary purpose was to determine whether the 400-m W could better discriminate physical performance among high functioning older adults by examining the distribution of 400-m W scores.

METHODS

101 men and women (80.8+/-0.4 years) were recruited to participate in the study. The 400-mW and SPPB assessed lower extremity function. Lower extremity muscle strength, power, and contraction velocity was assessed using bilateral leg press (LP). Health history was obtained with questionnaire.

RESULTS

400-m W demonstrated moderate correlations with SPPB (Pearson r=0.74; p< 0.001). In 36 high functioning individuals (SPPB score= 10, 11, 12), participants above the median 400-m W performance time (n=20) had more medical conditions (2.8+/-0.4 vs 1.7+/-0.3; p=0.038), more reported falls (0.80+/-0.2 vs 0.19+/-0.1; p=0.016), more medications (3.7+/-0.4 vs 1.8+/-0.4; p=0.001), had lower LP power at 70% of the one repetition maximum (1RM) (336+/-45 W vs 663+/-78 W; p=0.001) and 40% 1RM (329+/-43 W vs 580+/-75 W; p=0.005), and had slower LP contraction velocity at 40% 1RM (77+/-5.5 m/s vs 112+/-8.4 m/s; p=0.001) compared with those below the median (n=16).

CONCLUSIONS

A substantial number of apparently well functioning older adults demonstrated some limitations in the ability to walk 400 meters. Use of the 400-m W may be justified to obtain information to better discriminate among high functioning elderly.

CK-MM autoantibodies: Prevalence, immune complexes, and effect on CK clearance

Although the blood level of creatine kinase (CK) is the most commonly used marker of muscle injury, there is marked interindividual variability in this measure. Part of this variability may be attributed to variability in the rate of CK clearance from the circulation. In this study, we assessed the possibility that CK-MM autoantibodies form immune complexes with CK following muscle injury and subsequently affect the CK clearance rate. Using an enzyme-linked immunosorbent assay, CK-MM autoantibodies were detected in all 25 human subjects studied but the levels varied greatly. Using protein A-sepharose, the percentage of the plasma CK activity found in immune complexes was determined to be correlated with the CK-MM autoantibody level at lower CK levels (<1,022 U/L). When CK-MM antibodies were administered to mice, plasma CK activity following a bolus CK injection was reduced by 11%-32%. We conclude that CK-MM autoantibodies can modulate the rate of CK clearance from the circulation. Thus, the relatively low blood CK levels seen in some individuals following injury may be attributed partly or entirely to an autoantibody-enhanced clearance of CK.

Effect of leg muscle contraction velocity on functional performance in older men and women

OBJECTIVES

To explore the relationship between impairment (skeletal muscle strength and contraction velocity) and function in community-dwelling older adults.

DESIGN

Cross-sectional.

SETTING

University-based human physiology laboratory.

PARTICIPANTS

One hundred one men and women (aged 75-90).

MEASUREMENTS

Muscle strength and contraction velocity during bilateral leg press (LP) were calculated during one-repetition maximum (1RM) and 40% 1RM. A short physical performance battery (SPPB) and gait speed (GS) from a 400-m self-paced walk assessed function. Sex differences in LP strength and contraction velocity (at 40% 1RM) were assessed. The relationship between these variables and function was also examined.

RESULTS

Lower extremity strength and contraction velocity were significantly associated with GS (P=.02 and P=.005, respectively) and SPPB (P<.001 and P=.009, respectively) in men only. Contraction velocity, but not muscle strength, was significantly associated with GS (P<.001) and SPPB (P=.02) in women.

CONCLUSION

Sex differences exist in the relationship between impairment (muscle strength and contraction velocity) and function. Older men and women may employ different strategies to achieve success on different functional tasks. These findings may have important implications for clinicians practicing geriatric rehabilitation.

The effects of yoga training and a single bout of yoga on delayed onset muscle soreness in the lower extremity

The purpose of this study was to determine the effects of yoga training and a single bout of yoga on the intensity of delayed onset muscle soreness (DOMS). 24 yoga-trained (YT; n = 12) and non-yoga-trained (CON; n = 12), matched women volunteers were administered a DOMS-inducing bench-stepping exercise. Muscle soreness was assessed at baseline, 24, 48, 72, 96, and 120 hours after bench-stepping using a Visual Analog Scale (VAS). Groups were also compared on body awareness (BA), flexibility using the sit-and-reach test (SR), and perceived exertion (RPE). Statistical significance was accepted at p </= 0.05. A 2 x 2 mixed factorial ANOVA with repeated measures at 24 and 48 hours revealed a significant (p < 0.05) group main effect with VAS scores greater for CON than YT. Paired t-tests revealed that in YT, VAS scores were higher before yoga class than after yoga class at 24 hours (21.4 [+/- 6.9] mm vs. 11.1 [+/- 4.1] mm; p = 0.02). The SR was greater in YT than in CON (65.0 [+/- 7.9] cm vs. 33.3 [+/- 7.0] cm; p < 0.01); however, no differences were found between yoga and control in BA (94.0 [+/- 4.4] units vs. 83.8 [+/- 3.7] units; p = 0.21) or in RPE at 5-minute intervals (2.9 [+/- 0.3], 5.3 [+/- 0.8], 5.8 [+/- 0.9], and 5.2 [+/- 0.8] vs. 2.5 [+/- 0.3], 4.0 [+/- 0.5], 4.2 [+/- 0.3], and 4.9 [+/- 0.4]. Yoga training and a single bout of yoga appear to attenuate peak muscle soreness in women following a bout of eccentric exercise. These findings have significant implications for coaches, athletes, and the exercising public who may want to implement yoga training as a preseason regimen or supplemental activity to lessen the symptoms associated with muscle soreness.

Validation of the Late-Life Function and Disability Instrument

OBJECTIVES

To assess the concurrent and predictive validity of the Late-Life Function and Disability Instrument (LLFDI).

DESIGN

Cross-sectional.

SETTING

University-based human physiology laboratory.

PARTICIPANTS

One hundred one men and women aged 80.8 +/- 0.4.

MEASUREMENTS

A short physical performance battery (SPPB) and a self-paced 400-m walk (400-m W) were used as performance tests of lower extremity function. The LLFDI was used to assess self-reported function and physical disability. Partial correlations adjusted for age and body mass index were used to determine the concurrent and predictive validity of the LLFDI. Statistical significance was accepted at P<.004 using a testwise correction.

RESULTS

LLFDI Overall Function scores were moderately associated with the SPPB (r=0.65, P<.001), 400-m W gait speed (r=0.69, P<.001), and measures of lower extremity function. Correlations of the two lower extremity subscores of the LLFDI (correlation coefficient (r)=0.63-0.73, P<.001) were greater than for the LLFDI upper extremity subscores (r=0.19-0.26, P>.004). Performance measures of function predicted disability limitations in the range of r=0.37-0.44 (P<.001) and disability frequency in the range of r=0.16-0.20 (P>.004).

CONCLUSION

These findings support the concurrent and predictive validity of the LLFDI. Results support the use of the LLFDI scales as a substitute for physical performance tests when self-report is a preferred data-collection format.

Changes in function and disability after resistance training: does velocity matter?: a pilot study

OBJECTIVE

To compare the effects of high- and low-velocity resistance training on functional performance and disability outcomes in physically limited older women.

DESIGN

A total of 16 wk of high-velocity resistance training or traditional low-velocity resistance training consisting of knee extension and leg press exercises was performed three times per week by 30 women with self-reported disability to compare their effect on functional performance and disability. Tests of dynamic balance, stair-climb time, chair-rise time, and gait velocity were used to assess changes in functional performance. Changes in disability were assessed using the Medical Outcomes Study Short Form.

RESULTS

Dynamic balance and stair-climb time improved 8% and 10%, respectively, with training. Self-reported disability, physical functioning, role physical, and mental health improved 11, 9, and 5% with training, respectively. There were no significant differences between high- and low-velocity training groups.

CONCLUSIONS

High- and low-velocity training achieved similar improvements in functional performance and disability. Improvements in functional performance and disability were modest compared with robust increases in strength and power. Specific modes of training or behavioral strategies may be necessary to optimize improvements in these outcomes.

Short-term immobilization after eccentric exercise. Part II: creatine kinase and myoglobin

PURPOSE

Although creatine kinase (CK) is commonly used as a marker of muscle damage, there is large variability in the response to exercise. We previously found short-term immobilization blunted the rise in plasma CK after eccentric exercise, suggesting subsequent movement of damaged muscle may contribute to variability. We hypothesized that immobilization decreases lymphatic transport of CK from damaged muscle, blunting the CK response. In this study, we compared changes in plasma CK and myoglobin (Mb), as Mb is released from damaged muscle directly into the bloodstream whereas CK is released first into the lymph.

METHODS

Twenty-five college-age males were matched according to force loss after 50 maximal eccentric contractions of the elbow flexors and placed into an immobilization (IMM, N = 12) or control (CON, N = 13) group. IMM had their arm immobilized at 90 degrees and secured in a sling for 4 d (treatment). Venipuncture was performed during baseline, treatment, and for 5 d after treatment (recovery) to assess plasma CK activity and Mb. Urine specific gravity (USG) and muscle activity (ACT) were assessed.

RESULTS

Immobilization significantly blunted increases in CK activity (IMM: 955 +/- 316 IU.L-1 vs CON: 2884 +/- 1083 IU.L-1; P < 0.05) but not increases in Mb (IMM: 712 +/- 278 ng.mL-1 vs CON: 891 +/- 253 ng.mL-1; P > 0.05). There were no differences in USG between groups over time (P > 0.05) and no group differences in ACT (P > 0.05).

CONCLUSIONS

Short-term immobilization after eccentric exercise blunted the CK response but not the Mb response, suggesting lymphatic transport of CK may be responsible. Because hydration status and muscular activity after exercise were not different between groups, the blunted CK response was likely due to inactivation of CK activity before entering circulation.

Neuromuscular variables affecting the magnitude of force loss after eccentric exercise

The aim of this study was to examine neuromuscular variables contributing to differences in force loss after participants were exposed to the same relative bout of eccentric exercise. Thirty-six males performed 50 maximal eccentric contractions of the elbow flexors and were stratified into high responders (n = 10) and low responders (n = 10) based on force loss 36 h after exercise. Maximal voluntary isometric contractions (MVCs) and electromyography (EMG) were measured at baseline and 36 h after exercise. During eccentric exercise, mean peak torque, mean end-range torque from the final 25% of each trial and total angular impulse were computed over 25 contractions in each of two bouts. The slope of the change in these values for each 25 eccentric contractions was calculated for each participant using linear regression. At baseline, MVC was not different between groups (low responders: 97.0 +/- 9.6 N x m; high responders: 82.7 +/- 6.4 N x m; P = 0.08). High responders demonstrated a 68% (range 62-78%) reduction in MVC and low responders a 39% (29-48%) reduction after exercise. Peak torque, end-range torque and total angular impulse were 13%, 40% and 33% higher, respectively, in the low than in the high responders (peak torque: P = 0.0002; end-range torque: P < 0.0001; total angular impulse: P < 0.001). The rate of decline in peak torque slope was greater in high than in low responders (P = 0.044). In conclusion, lower peak torque, end-range torque and total angular impulse during eccentric contractions and a greater peak torque slope may identify high responders to eccentric exercise.

Short-term immobilization after eccentric exercise. Part I: contractile properties

PURPOSE

The purpose of this study was to examine the compound muscle action potential (M-wave) and evoked contractile properties of immobilized muscle after high-force eccentric exercise. We believed that changes in these variables would contribute to the enhanced recovery of maximal voluntary force observed after short-term immobilization of damaged muscle. We hypothesized that immobilization after eccentric exercise would result in an enhanced M-wave and a change in contractile properties toward characteristics of faster muscle fibers.

METHODS

Twenty-five college-age males were matched according to force loss after 50 maximal eccentric contractions of the elbow flexors and placed into an immobilization (IMM, N = 12) or control (CON, N = 13) group. IMM had their arm immobilized at 90 degrees and secured in a sling during a 4-d treatment. Maximal isometric torque (MVC) was assessed at baseline and for 8 d after treatment. M-wave and evoked contractile properties of the muscle (twitch torque [TT], maximal rate of torque development [MRTD], time to peak torque [TPT], and one-half relaxation time [HRT]) were assessed at baseline and for the first 5 d after treatment.

RESULTS

Immediately postexercise, MVC was reduced 43% and 42% in IMM and CON, respectively. Recovery of MVC was significantly greater in IMM during recovery (P < 0.05), 95% of baseline MVC compared with 83% in CON. M-wave was reduced 32%, and all contractile properties were altered immediately postexercise. M-wave, MRTD, TPT, and HRT were not significantly different between groups during recovery (P > 0.05). TT demonstrated enhanced recovery in IMM (P < 0.05).

CONCLUSIONS

Short-term immobilization after eccentric exercise resulted in enhanced recovery of maximal voluntary force. However, enhanced force recovery cannot be explained by muscle activation and evoked contractile properties of the muscle.

Treatment and prevention of delayed onset muscle soreness

Eccentric exercise continues to receive attention as a productive means of exercise. Coupled with this has been the heightened study of the damage that occurs in early stages of exposure to eccentric exercise. This is commonly referred to as delayed onset muscle soreness (DOMS). To date, a sound and consistent treatment for DOMS has not been established. Although multiple practices exist for the treatment of DOMS, few have scientific support. Suggested treatments for DOMS are numerous and include pharmaceuticals, herbal remedies, stretching, massage, nutritional supplements, and many more. DOMS is particularly prevalent in resistance training; hence, this article may be of particular interest to the coach, trainer, or physical therapist to aid in selection of efficient treatments. First, we briefly review eccentric exercise and its characteristics and then proceed to a scientific and systematic overview and evaluation of treatments for DOMS. We have classified treatments into 3 sections, namely, pharmacological, conventional rehabilitation approaches, and a third section that collectively evaluates multiple additional practiced treatments. Literature that addresses most directly the question regarding the effectiveness of a particular treatment has been selected. The reader will note that selected treatments such as anti-inflammatory drugs and antioxidants appear to have a potential in the treatment of DOMS. Other conventional approaches, such as massage, ultrasound, and stretching appear less promising.

Metabolic response to light exercise after exercise-induced rhabdomyolysis

Inherent compromises in substrate metabolism, or impaired perfusion of muscle may contribute to the occurrence of exercise-induced rhabdomyolysis. In this study, the lactate response of the elbow flexor muscles to light exercise was examined in eight subjects (five males, three females) who previously demonstrated rhabdomyolysis with extreme swelling (ES; n = 4) or no swelling (NS; n = 4) of the upper arm after eccentric exercise. Subjects performed identical light exercise bouts (45 s of rapid isotonic biceps curls consisting of both concentric and eccentric actions at 25% of maximum voluntary contraction force) using their previously eccentrically exercised arm (E-ARM) and control arm, which was not used previously to perform eccentric exercise (C-ARM). Blood lactate concentration ([La]b) was assessed 1.5, 3, 4.5, 6, and 9 min post-exercise. Peak [La]b and the area under the curve (AUC) were compared between the E-ARM of the ES and NS groups and between the C-ARM and E-ARM of the ES group. The AUC did not differ between the E-ARM of the ES and NS groups (P > 0.05) or between the C-ARM and E-ARM of the ES group (P > 0.05). In the ES group, the increase in [La]b after light exercise with the C-ARM [mean (SD) change, delta: 1.98 (0.7) mmol/l] was not different from the increase after exercising the E-ARM [delta: 2.10 (0.7) mmol/l; P>0.05]. Comparing the response of the E-ARM between groups, the increase in [La]b of the NS group [delta: 1.40 (0.4) mmol/l] was not different than that observed in the ES group [delta: 2.10 (0.7) mmol/l; P>0.05). Thus, subjects who had previously exhibited signs of exercise-induced rhabdomyolysis did not show an abnormal response to low-intensity anaerobic exercise.

Effect of ketoprofen on muscle function and sEMG activity after eccentric exercise

PURPOSE

This study examined whether ketoprofen, a nonsteroidal anti-inflammatory drug, attenuated muscle soreness (SOR), improved maximal isometric force (MIF) recovery, and/or altered myoelectric activity after high-force eccentric exercise.

METHODS

48 subjects were randomly assigned to one of four groups: CON: no exercise/no drug (N = 12); PLA: exercise + placebo (N = 12); TRT-100: exercise + 100 mg oral ketoprofen (N = 12); and TRT-25: exercise + 25 mg oral ketoprofen (N = 12). PLA, TRT-100, and TRT-25 were administered in a double-blind fashion. Baseline measurements of SOR, MIF, and surface electromyographic (EMG) amplitude were taken, and PLA, TRT-100, and TRT-25 performed 50 maximal eccentric contractions of the elbow flexors; 36 h later, subjects reporting moderate soreness were given ketoprofen or placebo and SOR measures were taken hourly for 8 h. EMG amplitude was assessed during MIF before dosing and again 8 h later and during submaximal contractions of 5%, 10%, and 20% of MIF before dosing and hourly for 8 h.

RESULTS

Eccentric exercise increased myoelectric activity during submaximal force measurements in PLA, TRT-100, and TRT-25 in all conditions. Ketoprofen had no effect on reducing this increase in EMG activity. Ketoprofen attenuated perceived SOR (P < 0.05) and enhanced MIF recovery (P < 0.05) compared with placebo. TRT-100 and TRT-25 demonstrated 10% and 19% reductions in SOR, respectively, and 16% and 9% increases in MIF, respectively, whereas PLA demonstrated a 1% increase in SOR and 9% decrease in MIF over 8 h.

CONCLUSION

Ketoprofen treatment after muscle damaging exercise reduces muscle soreness and improves force recovery.

Force recovery after eccentric exercise in males and females

In this study we investigated force loss and recovery after eccentric exercise, and further characterized profound losses in muscle function (n = 192 subjects--98 males, 94 females; population A). Maximal voluntary contractile force (MVC) was assessed before, immediately after, and at 36 and 132 h after eccentric exercise. Two groups were then established (A1 and A2). Group A1 demonstrated a > 70% reduction in MVC immediately after exercise, but were recovering at 132 h after exercise. These subjects performed a follow-up MVC 26 days later (n = 32). Group A2 demonstrated a > 70% reduction in MVC immediately post-exercise, but still exhibited a > 65% reduction in force at 132 h post-exercise; these subjects also performed a follow-up MVC every 7 days until full recovery was established (n = 9). In population A, there was a 57% reduction in MVC immediately post-exercise and a 67% recovery by 132 h post-exercise (P < 0.01), with no significant gender differences (P > 0.05). In group A1, although more females (two-thirds) showed large force losses after exercise, these females demonstrated greater %MVC recovery at 132 h post-exercise (59% vs 44%) and at 26 days post-exercise (93% vs 81%) compared to the males. In group A2, MVC recovery occurred between 33 and 47 days post-exercise. In conclusion, 21% of all subjects showed a delayed recovery in MVC after high-force eccentric exercise. Although there were no significant gender differences in force loss, a disproportionately larger number of females demonstrated force reductions of > 70%. However, their recovery of force was more rapid than that observed for the males who also demonstrated a > 70% force loss.

Activity and immobilization after eccentric exercise: I. Recovery of muscle function

PURPOSE

The purpose of the present study was to determine whether activity would affect the recovery of muscle function after high-force eccentric exercise of the elbow flexors.

METHODS

Twenty-six male volunteers were randomly assigned to one of three groups for a 4-d treatment period: immobilization (N = 9), control (N = 8), and light exercise (N = 9). Relaxed arm angle (RANG), flexed arm angle (FANG), maximal isometric force (MIF), and perceived muscle soreness (SOR) were obtained for 3 consecutive days pre-exercise (baseline), immediately post-exercise, and for 8 consecutive days after the 4-d treatment period (recovery). During the treatment period, the immobilization group had their arm placed in a cast and supported in a sling at 90 degrees. The control group had no restriction of their arm activity. The light exercise group performed a daily exercise regimen of 50 biceps curls with a 5-lb dumbbell.

RESULTS

All subjects showed a prolonged decrease in RANG, increase in FANG, loss in MIF, and increase in SOR in the days after eccentric exercise. During recovery, there was no significant interaction observed among groups over time in RANG (P > 0.05) or FANG (P > 0.05), but there was a significant interaction observed among groups over time in both MIF (P < 0.01) and SOR (P < 0.01). Recovery of MIF was facilitated by light exercise and immobilization, whereas recovery from SOR was facilitated by light exercise and delayed by immobilization.

CONCLUSIONS

The recovery of MIF in both the light exercise and immobilization groups suggests that more than one mechanism may be involved in the recovery of isometric force after eccentric exercise.