Test-Retest Reliability of Movement Displacement during a 20-s Stepping-in-Place Test in Community-Dwelling Older Adults with and without Supportive Care.

Introduction: Our recent reports have shown that movement pattern and displacement assessed with an infrared depth sensor during a 20-s stepping-in-place test (ST) correlates with measures of balance and need for assistance in older individuals. This study investigated ST test-retest reliability in community-dwelling older adults with and without supportive care.

Methods: Two groups were included: those not participating (HO: n = 25, 74.

The stepping test, and infrared depth sensor, provide reliable measures of balance in community-dwelling older adults.

[Purpose] The purpose was to examine relationships between variables characterizing the 20-second stepping test movement pattern, assessed with an infrared depth sensor (Kinect), and measurements of dynamic and static balance. [Participants and Methods] A total of 27 independent-living, older adults (7 males and 20 females) participated in this study. For each participant, the stepping test total movement distance, movement displacement, knee movement distance, and step number were calculated from Kinect closed joint-point coordinate data.

Prediction of Anaerobic Power From Standing Long Jump in NCAA Division IA Football Players.

Mann, JB, Bird, M, Signorile, JF, Brechue, WF, and Mayhew, JL. Prediction of anaerobic power from standing long jump in NCAA Division IA football players. J Strength Cond Res 35(6): 1542-1546, 2021-Despite the popularity of the standing long jump (SLJ), limited research has explored the estimation of power developed during this test.

A 20-sec Stepping Test and KINECT Sensor Provides Objective Quantification of Movement/Balance Dysfunction in Older Individuals.

: Tests such as the Functional Independence Measure (FIM) are widely used measures of infirmity and burden of care. However, these scales are largely qualitative and especially problematic when assessing movement-based tasks. Effective, reliable analysis of human movement is technically complicated and expensive, but an infrared depth sensor is potentially a low-cost, portable devise which may provide a quantitative aspect to clinical testing.

Validity and reliability of a novel instrumented one-legged hop test in patients with knee injuries.

Background: Conventional one-legged hop tests simply evaluate the total hop distance, thus neglecting important temporal and spatial parameters related to the strategy of execution, such as foot contact time.

Aim: To examine the validity and reliability of an instrumented one-legged hop test, the "four hops, three contacts" (4H3C) test, in patients with knee injuries.

Methods: The 4H3C test consists of four consecutive one-legged hops, of which individual hop distance and foot contact time are recorded by a validated floor-based photocell system.

Inter-Investigator Reliability of Anthropometric Prediction of 1RM Bench Press in College Football Players.

The purpose of this study was to determine the effect of inter-investigator differences in anthropometric assessments on the prediction of one-repetition maximum (1RM) bench press in college football players. Division-II players (n = 34, age = 20.4 ± 1.

The Association Between Serum Biomarkers of Collagen Turnover and Subsequent Anterior Cruciate Ligament Rupture.

Background: No study has attempted to associate the levels of preinjury serum biomarkers of collagen turnover with the subsequent risk of anterior cruciate ligament (ACL) injury.

Hypothesis: Preinjury serum biomarkers of collagen turnover would be associated with the subsequent risk of ACL injury.

Study Design: Case-control study; Level of evidence, 3.

Relationship Between Agility Tests and Short Sprints: Reliability and Smallest Worthwhile Difference in National Collegiate Athletic Association Division-I Football Players.

The Pro-Agility test (I-Test) and 3-cone drill (3-CD) are widely used in football to assess quickness in change of direction. Likewise, the 10-yard (yd) sprint, a test of sprint acceleration, is gaining popularity for testing physical competency in football players. Despite their frequent use, little information exists on the relationship between agility and sprint tests as well the reliability and degree of change necessary to indicate meaningful improvement resulting from training.

Validity and reliability of hand and electronic timing for 40-yd sprint in college football players.

The 40-yd sprint is the premier event for evaluating sprint speed among football players at all competitive levels. Some questions remain concerning the validity of hand timing compared with electronic timing, as well as the lack of assessment and reliability of each method. The purpose of this study was to evaluate the validity of hand timing by experienced and novice timers compared with electronic timing and to establish the reliability and smallest worthwhile difference (SWD) of each method for the 40-yd sprint.

Efficacy of the National Football League-225 Test to Track Changes in One Repetition Maximum Bench Press After Training in National Collegiate Athletic Association Division IA Football Players.

Numerous investigations have attested to the efficacy of the National Football League (NFL)-225 test to estimate one repetition maximum (1RM) bench press. However, no studies have assessed the efficacy of the test to track changes in strength across a training program. The purpose of this study was to determine the accuracy of the NFL-225 test for determining the change in 1RM bench press in National Collegiate Athletic Association Division IA college football players after training.

Progressive, Site-Specific Loss of Muscle Mass in Older, Frail Nursing Home Residents.

To clarify the progression of muscle loss in nursing home residents, frail women (n = 16; age: 85 ± 9 years; residence time: 764 days) were assessed for physical activity, caloric intake, and site-specific muscle thickness (MTH) and subcutaneous fat thickness (SFT) using B-mode ultrasound at nine anatomical sites at four intervals over one year. Height, body weight, and BMI did not change. Physical activity (246 steps/ day) and nutritional intake (1,441 kcal, 60.

Reliability and smallest worthwhile difference of the NFL-225 test in NCAA Division I football players.

The NFL-225 test is widely used to assess the strength level and evaluate the progress of college football players during resistance training. Despite the studies evaluating the validity of this test, there are no reports assessing its reliability. The purpose of this study was to determine the reliability and smallest worthwhile difference (SWD) of the NFL-225 test in Division I college football players.

Changes in serum biomarkers of cartilage turnover after anterior cruciate ligament injury.

Background: Biomarkers of cartilage turnover and joint metabolism have a potential use in detecting early degenerative changes after a traumatic knee joint injury; however, no study has analyzed biomarkers before an anterior cruciate ligament (ACL) injury and again after injury or in comparison with a similar group of uninjured controls.

Hypothesis: Changes in serum biomarker levels and the ratio of cartilage degradation to synthesis, from baseline to follow-up, would be significantly different between ACL-injured patients and uninjured controls.

Study Design: Case-control study; Level of evidence, 3.

Lower-body work capacity and one-repetition maximum squat prediction in college football players.

The purpose of this study was to assess lower-body muscular strength and work capacity after off-season resistance training and the efficacy of predicting maximal squat strength (1 repetition maximum [1RM]) from repetitions to fatigue. National Collegiate Athletic Association Division-II football players (n = 58) were divided into low-strength (LS, 1RM < 365 lb, n = 32) and high-strength (HS, 1RM ≥ 365 lb, n = 26) groups before training based on median 1RM squat performance. Maximal repetitions to failure (RTFs) were performed with a relative load of 70% of 1RM before training and 60, 70, 80, and 90% of 1RM after 12 weeks of a linear periodization resistance training program.

Impact of testing strategy on expression of upper-body work capacity and one-repetition maximum prediction after resistance training in college-aged men and women.

The purpose of this study was to assess the effect of resistance training on upper-body muscular strength and the expression of work capacity and muscular endurance. In addition, a training-induced change in the relationship between muscular strength and endurance was assessed by testing changes in the accuracy of using endurance repetitions to predict 1 repetition maximum (1RM) bench press before and after training. College-aged men (n = 85) and women (n = 62) completed a 12-week linear periodization resistance training program.

Characteristics of sprint performance in college football players.

To investigate sprinting strategy, acceleration and velocity patterns were determined in college football players (n = 61) during performance of a 9.1-, 36.6-, and 54.

Venous blood gas and metabolite response to low-intensity muscle contractions with external limb compression.

The effect of low-intensity resistance exercise with external limb compression (100 [EC100] and 160 [EC160] mm Hg) on limb blood flow and venous blood gas-metabolite response was investigated and compared with that of high-intensity resistance exercise (no external compression). Unilateral elbow flexion muscle contractions were performed at 20% (75 repetitions, 4 sets, 30-second rest intervals) and 70% of 1-repetition maximum (1-RM; 3 sets, each set was until failure, 3-minute rest intervals). Precontraction brachial arterial blood flow (Doppler ultrasound) was reduced with EC100 or EC160 (56% and 39% of baseline value, respectively) compared with no external compression (control).

Comparison between hand and electronic timing of 40-yd dash performance in college football players.

The purpose of this study was to determine the difference between hand and electronic timing of 40-yd dashes in college football players. National Collegiate Athletic Association Division II players (n = 59) were measured during a 40-yd sprint by electronic timing and simultaneously by 7 experienced hand timers using digital stopwatches. Electronic times were initiated by lifting the hand from a switch mat and stopped by the torso passing through an infrared beam.

Metabolic and cardiovascular responses to upright cycle exercise with leg blood flow reduction.

The purpose of this study was to examine the metabolic and cardiovascular response to exercise without (CON) or with (BFR) restricted blood flow to the muscles. Ten young men performed upright cycle exercise at 20, 40, and 60% of maximal oxygen uptake, VO2max in both conditions while metabolic and cardiovascular parameters were determined. Pre-exercise VO2 was not different between CON and BFR.

Upper-body work capacity and 1RM prediction are unaltered by increasing muscular strength in college football players.

The purpose of this study was to assess changes in upper-body muscular strength and work capacity following off-season resistance training and the resultant effect on prediction of muscular strength (1 repetition maximum, or 1RM). National Collegiate Athletic Association (NCAA) Division II football players (n = 58) were divided into low-strength (LS, 1RM <275 lb, n = 23) and high-strength (HS, 1RM > or =275 lb, n = 35) groups based on initial 1RM bench press. Maximal repetitions to failure (RTF) were performed with a relative (60, 70, 80, and 90% of 1RM) and absolute load (185 lb for players with 1RM <275 lb; 225 lb for players with 1RM > or =275 lb) at pre- and post-training.

Muscle activation during low-intensity muscle contractions with restricted blood flow.

We examined muscle activation during low-intensity muscle contractions with a moderate restriction of blood flow and complete occlusion of blood flow. Unilateral elbow flexion muscle contractions (20% of 1-RM) were performed in Experiment 1 (30 contractions), Experiment 2 (3 sets x 10 contractions), and Experiment 3 (30 repetitive contractions followed by 3 sets x 15 contractions) with moderate restriction, complete occlusion of blood flow or unrestricted blood flow (control). Electromyography (EMG) was recorded from surface electrodes placed on the biceps brachii muscle and the integrated EMG (iEMG) and mean power frequency (MPF) obtained.

Muscle activation during low-intensity muscle contractions with varying levels of external limb compression.

The purpose was to investigate muscle activation during low- intensity muscle contractions with various levels of external limb compression to reduce muscle perfusion/outflow. A series of unilateral elbow flexion muscle contractions (30 repetitive contractions followed by 3 sets x 15 contractions) was performed at 20% of 1RM with varying levels of external compression (0 (without compression), 98, 121, and 147 mmHg external compression) around the upper arm. Electromyography (EMG) signals were recorded from surface electrodes placed on the biceps brachii muscle and analyzed for integrated EMG (iEMG).

Equipment and running surface alter sprint performance of college football players.

The purpose of this study was to determine the effect of football equipment and running surface on sprint performance in NCAA Division II football players (n = 68). Players were timed in the 40-yd sprint on an indoor rubberized track (Day 1) and on an outdoor, natural-grass football field (Day 2) wearing either regulation football equipment or shorts and a T-shirt. Each player was assigned randomly to perform 2 trials under each condition on each surface, and the average of the 2 trials was used for analysis.

Depression of h-reflex following carbonic anhydrase inhibition appears unrelated to changes in synaptic effectiveness.

Presynaptic inhibition (PI) of Ia afferents was examined as a possible contributor to the depression of the soleus H-reflex following carbonic anhydrase (CA) inhibition with Acetazolamide (ACZ). Ten males (aged 22-32) were studied in two randomized conditions, control and ACZ administration (250 mg 14, 8, and 2 h before testing) separated by at least one week. PI of soleus Ia afferents was indirectly assessed two ways: a conditioning stimulus of Ia afferents in the common peroneal nerve (N = 6), and heteronymous Ia facilitation from the quadriceps to soleus muscle (N = 4).