The purpose of this Position Stand is to provide guidance to professionals who counsel and prescribe individualized exercise to apparently healthy adults of all ages. These recommendations also may apply to adults with certain chronic diseases or disabilities, when appropriately evaluated and advised by a health professional. This document supersedes the 1998 American College of Sports Medicine (ACSM) Position Stand, "The Recommended Quantity and Quality of Exercise for Developing and Maintaining Cardiorespiratory and Muscular Fitness, and Flexibility in Healthy Adults." The scientific evidence demonstrating the beneficial effects of exercise is indisputable, and the benefits of exercise far outweigh the risks in most adults. A program of regular exercise that includes cardiorespiratory, resistance, flexibility, and neuromotor exercise training beyond activities of daily living to improve and maintain physical fitness and health is essential for most adults. The ACSM recommends that most adults engage in moderate-intensity cardiorespiratory exercise training for ≥30 min·d on ≥5 d·wk for a total of ≥150 min·wk, vigorous-intensity cardiorespiratory exercise training for ≥20 min·d on ≥3 d·wk (≥75 min·wk), or a combination of moderate- and vigorous-intensity exercise to achieve a total energy expenditure of ≥500-1000 MET·min·wk. On 2-3 d·wk, adults should also perform resistance exercises for each of the major muscle groups, and neuromotor exercise involving balance, agility, and coordination. Crucial to maintaining joint range of movement, completing a series of flexibility exercises for each the major muscle-tendon groups (a total of 60 s per exercise) on ≥2 d·wk is recommended. The exercise program should be modified according to an individual's habitual physical activity, physical function, health status, exercise responses, and stated goals. Adults who are unable or unwilling to meet the exercise targets outlined here still can benefit from engaging in amounts of exercise less than recommended. In addition to exercising regularly, there are health benefits in concurrently reducing total time engaged in sedentary pursuits and also by interspersing frequent, short bouts of standing and physical activity between periods of sedentary activity, even in physically active adults. Behaviorally based exercise interventions, the use of behavior change strategies, supervision by an experienced fitness instructor, and exercise that is pleasant and enjoyable can improve adoption and adherence to prescribed exercise programs. Educating adults about and screening for signs and symptoms of CHD and gradual progression of exercise intensity and volume may reduce the risks of exercise. Consultations with a medical professional and diagnostic exercise testing for CHD are useful when clinically indicated but are not recommended for universal screening to enhance the safety of exercise.

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Quantity and Quality of Exercise for Developing and Maintaining Cardiorespiratory, Musculoskeletal, and Neuromotor Fitness in Apparently Healthy Adults: Guidance for Prescribing Exercise

Minimal measurement error (reliability) during the collection of interval- and ratio-type data is critically important to sports medicine research. The main components of measurement error are systematic bias (e.g. general learning or fatigue effects on the tests) and random error due to biological or mechanical variation. Both error components should be meaningfully quantified for the sports physician to relate the described error to judgements regarding ‘analytical goals’ (the requirements of the measurement tool for effective practical use) rather than the statistical significance of any reliability indicators.

Statistical Methods For Assessing Measurement Error (Reliability) in Variables Relevant to Sports Medicine

Delayed onset muscle soreness (DOMS) is a familiar experience for the elite or novice athlete. Symptoms can range from muscle tenderness to severe debilitating pain. The mechanisms, treatment strategies, and impact on athletic performance remain uncertain, despite the high incidence of DOMS. DOMS is most prevalent at the beginning of the sporting season when athletes are returning to training following a period of reduced activity. DOMS is also common when athletes are first introduced to certain types of activities regardless of the time of year. Eccentric activities induce micro-injury at a greater frequency and severity than other types of muscle actions. The intensity and duration of exercise are also important factors in DOMS onset. Up to six hypothesised theories have been proposed for the mechanism of DOMS, namely: lactic acid, muscle spasm, connective tissue damage, muscle damage, inflammation and the enzyme efflux theories. However, an integration of two or more theories is likely to explain muscle soreness. DOMS can affect athletic performance by causing a reduction in joint range of motion, shock attenuation and peak torque. Alterations in muscle sequencing and recruitment patterns may also occur, causing unaccustomed stress to be placed on muscle ligaments and tendons. These compensatory mechanisms may increase the risk of further injury if a premature return to sport is attempted. A number of treatment strategies have been introduced to help alleviate the severity of DOMS and to restore the maximal function of the muscles as rapidly as possible. Nonsteroidal anti-inflammatory drugs have demonstrated dosage-dependent effects that may also be influenced by the time of administration. Similarly, massage has shown varying results that may be attributed to the time of massage application and the type of massage technique used. Cryotherapy, stretching, homeopathy, ultrasound and electrical current modalities have demonstrated no effect on the alleviation of muscle soreness or other DOMS symptoms. Exercise is the most effective means of alleviating pain during DOMS, however the analgesic effect is also temporary. Athletes who must train on a daily basis should be encouraged to reduce the intensity and duration of exercise for 1–2 days following intense DOMS-inducing exercise. Alternatively, exercises targeting less affected body parts should be encouraged in order to allow the most affected muscle groups to recover. Eccentric exercises or novel activities should be introduced progressively over a period of 1 or 2 weeks at the beginning of, or during, the sporting season in order to reduce the level of physical impairment and/or training disruption. There are still many unanswered questions relating to DOMS, and many potential areas for future research.

Delayed onset muscle soreness : treatment strategies and performance factors.

Synopsis During the last decade, there has been a growing body of literature suggesting that proximal factors may play a contributory role with respect to knee injuries. A review of the biomechanical and clinical studies in this area indicates that impaired muscular control of the hip, pelvis, and trunk can affect tibiofemoral and patellofemoral joint kinematics and kinetics in multiple planes. In particular, there is evidence that motion impairments at the hip may underlie injuries such as anterior cruciate ligament tears, iliotibial band syndrome, and patellofemoral joint pain. In addition, the literature suggests that females may be more disposed to proximal influences than males. Based on the evidence presented as part of this clinical commentary, it can be argued that interventions which address proximal impairments may be beneficial for patients who present with various knee conditions. More specifically, a biomechanical argument can be made for the incorporation of pelvis and trunk stability, as we...

https://www.jospt.org/doi/pdf/10.2519/jospt.2010.3337

The Influence of Abnormal Hip Mechanics on Knee Injury: A Biomechanical Perspective

Although patellofemoral pain (PFP) is recognized as being one of the most common disorders of the lower extremity, treatment guidelines and underlying rationales remain vague and controversial. The premise behind most treatment approaches is that PFP is the result of abnormal patellar tracking and/or patellar malalignment. Given as such, interventions typically focus on the joint itself and have traditionally included strengthening the vastus medialis oblique, taping, bracing, soft tissue mobilization, and patellar mobilization. More recently, it has been recognized that the patellofemoral joint and, therefore, PFP may be influenced by the interaction of the segments and joints of the lower extremity. In particular, abnormal motion of the tibia and femur in the transverse and frontal planes may have an effect on patellofemoral joint mechanics. With this in mind, interventions aimed at controlling hip and pelvic motion (proximal stability) and ankle/foot motion (distal stability) may be warranted and shoul...

/pdf/the-influence-of-altered-lower-extremity-kinematics-on-ip4mgr5mwu.pdf

The Influence of Altered Lower-Extremity Kinematics on Patellofemoral Joint Dysfunction: A Theoretical Perspective

Background and Purpose. Stretching protocols for elderly people (≥65 years of age) have not been studied to determine the effectiveness of increasing range of motion (ROM). The purpose of this study was to determine which of 3 durations of stretches would produce and maintain the greatest gains in knee extension ROM with the femur held at 90 degrees of hip flexion in a group of elderly individuals. Subjects. Sixty-two subjects (mean age=84.7 years, SD=5.6, range= 65–97) with tight hamstring muscles (defined as the inability to extend the knee to less than 20° of knee flexion) participated. Subjects were recruited from a retirement housing complex and were independent in activities of daily living. Methods. Subjects were randomly assigned to 1 of 4 groups and completed a physical activity questionnaire. The subjects in group 1 (n=13, mean age=85.1 years, SD=6.4, range=70–97), a control group, performed no stretching. The randomly selected right or left limb of subjects in group 2 (n=17, mean age=85.5 years, SD=4.5, range=80–93), group 3 (n=15, mean age=85.2 years, SD=6.5, range=65–92), and group 4 (n=17, mean age=83.2 years, SD=4.6, range=68–90) was stretched 5 times per week for 6 weeks for 15, 30, and 60 seconds, respectively. Range of motion was measured once a week for 10 weeks to determine the treatment and residual effects. Data were analyzed using a growth curve model. Results. A 60-second stretch produced a greater rate of gains in ROM (60-second stretch=2.4° per week, 30-second stretch=1.3° per week, 15-second stretch=0.6° per week), which persisted longer than the gains in any other group (group 4 still had 5.4° more ROM 4 weeks after treatment than at pretest as compared with 0.7° and 0.8° for groups 2 and 3, respectively). Discussion and Conclusion. Longer hold times during stretching of the hamstring muscles resulted in a greater rate of gains in ROM and a more sustained increase in ROM in elderly subjects. These results may differ from those of studies performed with younger populations because of age-related physiologic changes.

The Effect of Duration of Stretching of the Hamstring Muscle Group for Increasing Range of Motion in People Aged 65 Years or Older

Study Design A randomized, counterbalanced 2×3×5 repeated-measures design Objective To compare changes in hamstring flexibility after treatments of pulsed shortwave diathermy and prolonged stretch, sham diathermy and prolonged stretch, and control Background Heat and stretch techniques have been touted for years To date, the effect of shortwave diathermy and hamstring stretching has not been studied Because diathermy heats a large area and penetrates deep into the muscle, use of this device prior to or during hamstring stretching may increase flexibility Methods and Measures Thirty college-age students (mean age, 215 years) with tight hamstrings (inability to achieve greater than 160° knee extension at 90° hip flexion) participated Subjects were assigned to 1 of 3 groups: diathermy and stretch, sham diathermy and stretch, and control) Range of motion was recorded before and after each treatment for 5 days and on day 8 A straight leg-raise stretch was performed using a mechanical apparatus Subjec

https://www.jospt.org/doi/pdfplus/10.2519/jospt.2004.34.1.13

Shortwave diathermy and prolonged stretching increase hamstring flexibility more than prolonged stretching alone.

We assessed the reliability of the KT-2000 knee ar thrometer at 67, 89, 134, and 178 N and at manual maximum forces on 30 college students who were free from present or previous knee injuries. Two examiners tested all subjects on two occasions. Anterior laxity (P < 0.0001) and side-to-side difference (P < 0.05) sig nificantly increased as force increased. There was a significant difference (P < 0.0001) between testers for anterior laxity but not for side-to-side difference. We used intraclass correlation coefficients to estimate rel ative reliability. Anterior laxity intraclass correlation co efficients (2,1) between testers ranged from 0.81 to 0.86 and within tester correlations ranged from 0.92 to 0.95. Intraclass correlation coefficients for between testers for side-to-side differences ranged from 0.38 to 0.58 and within tester correlations ranged from 0.53 to 0.64. Subject-to-subject variability needs to be taken into account when interpreting intraclass correlation coefficient values. Our absolute re...

Relative and Absolute Reliability of the KT-2000 Arthrometer for Uninjured Knees Testing at 67, 89, 134, and 178 N and Manual Maximum Forces

Objective Therapeutic ultrasound is an effective deep heating modality commonly applied alone or after cooling or heating of the treatment area. The purpose of this study was to examine the tissue temperature rise in the human triceps surae muscle group after ultrasound with prior heating via a silicate gel hot pack. Design and setting This study was designed as a 2 x 2 x 3 factorial with repeated measures on two factors (depth and time). Independent variables were temperature of pack (hot and room temperature), depth of measurement (1 cm and 3 cm), and time (beginning, after pack application, and after ultrasound). The dependent variable was tissue temperature. Subjects were assigned to one of two treatment groups: ultrasound preceded by a 15-minute hot pack treatment or ultrasound preceded by a 15-minute application with a silicate gel pack at room temperature. Measurements were taken while subjects were treated in a university training room. Subjects Twenty-one uninjured male and female college student volunteers were randomly assigned to one of the two pack groups. Measurements The hot packs were stored in 75 degrees C water. A 1-MHz ultrasound treatment was administered for 10 minutes at an intensity of 1.5 W/cm(2). Tissue temperature was measured every 30 seconds using 23-gauge hypodermic microprobes interfaced with a telethermometer and inserted 1 and 3 cm below the surface of anesthetized triceps surae muscle. Results At both tissue depths, there was a 0.8 degrees C greater increase in tissue temperature with hot packs and ultrasound. At 1 cm, ultrasound increased temperature 3.5 degrees C after a 0.5 degrees C rise during the room temperature-pack application, but only 0.6 degrees C after a 3.8 degrees C increase during hot-pack application. At 3 cm, ultrasound increased temperature 3.85 degrees C following a slight (-0.26 degrees C) decrease during the room temperature-pack application and 3.68 degrees C after a 0.74 degrees C increase during hot-pack application. Conclusions Vigorous increases in deep muscle temperature (>/=4 degrees C) can be reached with 2 to 3 minutes less total sonation time when preheated with a hot pack. Thus, ultrasound and hot packs have an additive effect on intramuscular temperature, but the characteristics of the additive effect are different, primarily because there appears to be a tissue temperature plateau.

Hot-Pack and 1-MHz Ultrasound Treatments Have an Additive Effect on Muscle Temperature Increase.

https://www.archives-pmr.org/article/S0003-9993(05)01377-8/pdf

Shane S. Schulthies

Papers

The Effect of Duration of Stretching of the Hamstring Muscle Group for Increasing Range of Motion in People Aged 65 Years or Older

Shortwave diathermy and prolonged stretching increase hamstring flexibility more than prolonged stretching alone.

Relative and Absolute Reliability of the KT-2000 Arthrometer for Uninjured Knees Testing at 67, 89, 134, and 178 N and Manual Maximum Forces

Hot-Pack and 1-MHz Ultrasound Treatments Have an Additive Effect on Muscle Temperature Increase.

Effects of Neuromuscular Training on the Reaction Time and Electromechanical Delay of the Peroneus Longus Muscle