Clinic and Home-Based Exercise with Blood Flow Restriction Resolves Thigh Muscle Atrophy after Anterior Cruciate Ligament Reconstruction with the Bone-Patellar Tendon-Bone Autograft: A Case Report.

Anterior cruciate ligament reconstruction (ACLR) results in thigh muscle atrophy. Of the various interventions proposed to mitigate thigh muscle atrophy, exercise with blood flow restriction (BFR) appears safe and effective. Some literature suggests daily exposure to exercise with BFR may be indicated during the early phase of ACLR rehabilitation; this case report outlines the methodology utilized to prescribe clinic- and home-based BFR within an outpatient rehabilitation program. A 15-year-old male soccer player suffered a left knee injury involving the anterior cruciate ligament and both menisci. He underwent ACLR and completed exercise with BFR as part of his clinic- and home-based rehabilitation program, which included practical blood flow restriction during home-based rehabilitation. After 16 weeks of rehabilitation, surgical limb thigh girth values were objectively larger than the non-surgical limb (surgical, 52.25 cm; non-surgical 50 cm), as well as the multi-frequency bioelectrical impedance analysis of his lower-extremity lean body mass (surgical limb, 10.37 kg; non-surgical limb, 10.02 kg). The findings of this case report suggest that the inclusion of clinic- and home-based BFR within an outpatient rehabilitation program may be indicated to resolve thigh muscle atrophy early after ACLR.

Femur Length is Correlated with Isometric Quadriceps Strength in Post-Operative Patients.

BACKGROUND: Few existing studies have examined the relationship between lower extremity bone length and quadriceps strength. PURPOSE/HYPOTHESIS: To evaluate the relationship between lower extremity, tibia and femur lengths, and isometric quadriceps strength in patients undergoing knee surgery. The null hypothesis was that there would be no correlation between lower extremity length and isometric quadriceps strength. STUDY DESIGN: Cross-sectional study. METHODS: Patients with full-length weightbearing radiographs that underwent isometric quadriceps strength testing after knee surgery were included. Using full-length weightbearing radiographs, limb length was measured from the ASIS to the medial malleolus; femur length was measured from the center of the femoral head to the joint line; tibia length was measured from the center of the plateau to the center of the plafond. Isometric quadriceps strength was measured using an isokinetic dynamometer. Pearson's correlation coefficient was used to report the correlation between radiographic limb length measurements. A Bonferroni correction was utilized to reduce the probability of a Type 1 error. RESULTS: Forty patients (26 males, 14 females) with an average age of 25.8 years were included. The average limb, femur, and tibia lengths were not significantly different between operative and non-operative limbs (p>0.05). At an average of 5.8±2.5 months postoperatively, the peak torque (156.6 vs. 225.1 Nm), average peak torque (151.6 vs. 216.7 Nm), and peak torque to bodyweight (2.01 vs 2.89 Nm/Kg) were significantly greater in the non-surgical limb (p<0.01). Among ligament reconstructions there was a significant negative correlation between both limb length and strength deficit (r= -0.47, p=0.03) and femur length and strength deficit (r= -0.51, p=0.02). The average strength deficit was 29.6% among the entire study population; the average strength deficit was 37.7% among knee ligament reconstructions. For the non-surgical limb, femur length was significantly correlated with peak torque (r = 0.43, p = 0.048). CONCLUSION: Femur length was significantly correlated with the isometric quadriceps peak torque for non-surgical limbs. Additionally, femur length and limb length were found to be negatively correlated with quadriceps strength deficit among ligament reconstruction patients. A combination of morphological features and objective performance metrics should be considered when developing individualized rehabilitation and strength programs.

Quadriceps Strength following Anterior Cruciate Ligament Reconstruction: Normative Values based on Sex, Graft Type and Meniscal Status at 3, 6 & 9 Months.

Background: Higher postoperative quadriceps function has been positively associated with surgical outcomes after anterior cruciate ligament reconstruction (ACLR). However, the impact of autograft harvest and/or a concomitant meniscal procedure on the recovery of quadriceps strength is not well defined. Purpose: To describe postoperative recovery of quadriceps strength following ACLR related to autograft selection, meniscal status, and sex. Study Design: Retrospective Cohort. Methods: One hundred and twenty-five participants who underwent ACLR with either a hamstring tendon (HT), bone-patellar tendon-bone (BPTB) or quadriceps tendon (QT) autograft were included. At postoperative months 3, 6 and 9, each participant completed an isometric quadriceps strength testing protocol at 90-degrees of knee flexion. Participants' quadriceps average peak torque (Q-AvgPKT), average peak torque relative to body weight (Q-RPKT), and calculated limb symmetry index (Q-LSI) were collected and used for data analysis. Patients were placed in groups based on sex, graft type, and whether they had a concomitant meniscal procedure at the time of ACLR. At each time point, One-way ANOVAs, independent samples t-test and chi-square analyses were used to test for any between-group differences in strength outcomes. Results: At three months after ACLR, Q-RPKT was significantly higher in those with the HT compared to the QT. At all time points, males had significantly greater Q-RPKT than females and HT Q-LSI was significantly higher than BPTB and QT. A concomitant meniscal procedure at the time of ACLR did not significantly affect Q-LSI or Q-RPKT at any testing point. Conclusion: This study provides outcomes that are procedure specific as well as highlights the objective progression of quadriceps strength after ACLR. This information may help better-define the normal recovery of function, as well as guide rehabilitation strategies after ACLR. Level of Evidence: 3.

Physical Preparation Strategies of Professional Jockeys.

ABSTRACT: Kiely, M, Warrington, G, McGoldrick, A, and Cullen, S. Physical preparation strategies of professional jockeys. J Strength Cond Res 36(11): 3184-3189, 2022-Professional horse racing is a physically demanding sport. The aim of the study was to examine the physical preparation strategies of jockeys for racing. A questionnaire was developed and validated which comprised of 4 sections; (a) background information, (b) making weight and current associated exercise habits, (c) current physical activity practices, and (d) jockey perceptions of strength and conditioning (S&C) and current practices. Eighty-five jockeys ( n = 38 professional flat, n = 47 professional jump) completed the questionnaire in race course weighing rooms representing 80% of the professional athlete population. In total, 77.6% of jockeys participate in physical activity outside of riding. Jockeys that participated in S&C (42.4%) reported their most frequent type of S&C practice; cardio (52.8%), high-intensity interval training (33.3%), flexibility and mobility training (8.3%), resistance training (5.6%). There was no significant difference in S&C participation between total flat and total jump licenses ( p = 0.530; [PHI] = 0.068). Difficulty making weight was reported by 55.3% of jockeys. Exercise alone was used by 29.4% of jockeys to rapidly reduce weight. There was no significant difference ( p = 0.201, [PHI] = 0.357) between the frequency of rapid weight loss per month for total flat (1.7 ± 1.7) and total jump jockeys (1.6 ± 0.5). This study represents the only published data on the physical preparation strategies of jockeys. Jockeys do not partake in physical activity, which mimics the repeated high-intensity demands of racing. Future research is required to examine the effects of specific S&C interventions on riding performance.

Competition Volume and Changes in Countermovement Jump Biomechanics and Motor Signatures in Female Collegiate Volleyball Players.

ABSTRACT: Kipp, K, Kiely, M, and Geiser, C. Competition volume and changes in countermovement jump biomechanics and motor signatures in female collegiate volleyball players. J Strength Cond Res 35(4): 970-975, 2021-The purpose of this study was to investigate the relationship between competition volume and preseason to postseason changes in countermovement jump (CMJ) biomechanics and motor signatures in female collegiate volleyball players. Ten National Collegiate Athletic Association Division I female volleyball players performed CMJs on force plates before (PRE) and after (POST) their season. Countermovement jump height was calculated, and 4 discrete biomechanical variables (peak body-mass normalized force [PeakF], peak body-mass normalized rate of force development [PeakRFD], movement time [TIME], and the ratio between eccentric and total movement time [EccT:TIME]) were calculated. A factor analysis of the 4 biomechanical variables was used to identify CMJ motor signatures. The total number of sets played by each player was used to define total competition volume for the season. Correlation coefficients were used to investigate the associations between competition volume and changes in CMJ height, discrete biomechanical variables, and the components of the CMJ motor signature. The statistical analysis indicated that team-average jump height did not change over the course of the season. However, competition volume was negatively associated with changes in CMJ height, such that decreases in CMJ height over the course of the season occurred in players who played large numbers of sets. Although CMJ during POST testing was characterized by longer TIME and greater PeakRFD, CMJ motor signatures did not change and suggest that the female volleyball players in this study retained their preferred jumping strategy across the season. Given that decreases in CMJ height were most pronounced in players who played the most sets, and scored the most points during the season, future research may need to focus on player- or position-specific interventions that help players retain CMJ performance in the face of the competitive demands of a collegiate volleyball season.

Physiological Demands of Professional Flat and Jump Horse Racing.

Kiely, M, Warrington, GD, McGoldrick, A, Pugh, J, and Cullen, S. Physiological demands of professional flat and jump horse racing. J Strength Cond Res 34(8): 2173-2177, 2020-No information is currently available on the effect of race distance on the physiological demands of jockeys. This study aimed to quantify the respective demands of short and long flat and jump race distances. Twenty professional jockeys (10 flat and 10 jump) participated in the study. The subjects initially performed a graded incremental exercise test to volitional exhaustion on a treadmill to determine the peak heart rate (HR) and blood lactate concentrations. Two competitive races (short and long) were then monitored on 2 separate occasions for each jockey type to obtain hydration, HR, blood lactate concentration, and rating of perceived exertion data. Mean distances for the 4 races were: 1,247.2 ± 184.7 m (short flat race), 2,313.4 ± 142.2 m (long flat race), 3,480.2 ± 355.3 m (short jump race), and 4,546.4 ± 194.3 m (long jump race). The mean HR for the long flat race was 151 ± 19 b·min (79 ± 11% of HRpeak), which was significantly lower than all other race distances (p = 0.000, effect size [ES] = 0.469). A longer jump race resulted in a significantly higher reported rate of perceived exertion (RPE) (14 ± 2.8) than the short jump race (11.0 ± 1.5) (p = 0.009, ES = 0.271), whereas no significant difference was revealed between peak HR responses or blood lactate concentrations when comparing other race distances (p < 0.05). The finding of this study supports previous limited research, which suggests that horse racing is a high-intensity sport, whereas RPE and mean HR fluctuate according to the race distance.

Joint- and subject-specific strategies in male basketball players across a range of countermovement jump heights.

The purpose of this study was to investigate subject- and joint-specific strategies used by male basketball players as they increase their countermovement jump (CMJ) height from sub-maximal to maximal efforts. Lower extremity joint kinematics and kinetics were recorded as 11 male, NCAA Division I basketball players performed 8-10 CMJ across effort levels of approximately 25%, 50%, 75% and 100%. Simple correlation models were used to investigate the associations between effort levels (i.e., CMJ height) and joint mechanics (i.e., negative (eccentric) and positive (concentric) mechanical work performed at the hip, knee, and ankle joints) for each individual player and the entire group. Group-analyses showed that increases in all joint mechanical variables were associated with increases in CMJ height. In contrast, single-subject analyses revealed that players used individualised strategies, and selectively scaled the magnitude of mechanical work at none (n = 2), one (n = 2), two (n = 5), or all three (n = 2) joints as they increased CMJ efforts. In addition, individual players also appeared to selectively scale different combinations of eccentric or concentric joint work as they increased CMJ height. These results highlight that male basketball players use joint-specific strategies to increase CMJ height when progressively increasing CMJ effort.

Physiological demands of daily riding gaits in jockeys.

BACKGROUND: Jockeys should maintain a high level of physical fitness to meet the physical demands of horse racing. The aim of this study was to determine the physiological requirements of the riding gaits used regularly in training. METHODS: Eleven trainee jockeys performed a maximal incremental Wattbike cycle ergometer test. Mean absolute and relative oxygen uptake (VO2) and heart rate (HR) were recorded for the steady-state period during a walk, trot and canter. Energy expenditure (EE) and associated metabolic equivalent (MET) were also estimated. RESULTS: During a walk, trot and canter, relative mean VO2 corresponded to 15±4%, 38±6%, 47±9% of VO2peak and mean HR corresponded to 48±6%, 60±6%, 71±7% of HRpeak respectively. Mean VO2 and mean HR were significantly different amongst gaits; P≤0.001. Walking required the lowest estimated EE of 2.25±0.6 kcal.min-1 (P≤0.001; 2.4 METs;) and it was significantly lower than trotting at 5.72±1.0 kcal.min-1 (P≤0.001; 6.2 METs) and cantering at 7.10±1.8 kcal.min-1 (P≤0.001; 7.7 METs). CONCLUSIONS: These riding activities are associated with relatively low physiological demand and alternate modes of exercise are recommended for trainee jockeys to ensure the demands of racing are met. Future research should investigate the physical training, both riding-specific and general conditioning, jockeys perform in preparation for racing.

Biomechanical Determinants of the Reactive Strength Index During Drop Jumps.

The Reactive Strength Index (RSI) is often used to quantify drop-jump (DJ) performance; however, not much is known about its biomechanical determinants. The purpose of this study was to investigate the correlations between the RSI and several biomechanical variables calculated from DJ performed with different initial drop heights. Twelve male NCAA Division I basketball players performed DJs from drop heights of 30, 45, and 60 cm. Force plates were used to calculate DJ performance parameters (ie, DJ height, contact time, and RSI) and DJ biomechanical variables (ie, vertical stiffness and eccentric/concentric energetics). Regression analyses were used to assess the correlations between variables at each drop height, and ANOVAs were used to assess the differences of all variables across drop heights. Follow-up analyses used 2 neural networks to determine if DJ performance and biomechanical data could accurately classify DJ trials by drop-height condition. Vertical-stiffness values were significantly correlated with RSI at each height but did not change across drop heights. Surprisingly, the RSI and other DJ parameters also did not vary across drop height, which resulted in the inability of these variables to accurately classify DJ trials. Given that vertical stiffness did not change across drop height and was highly correlated with RSI at each height, the RSI appears to reflect biomechanical behavior related to vertical stiffness during DJ. However, the inability of the RSI to accurately classify drop-height condition questions the use of RSI profiles established from DJs from different heights.

Mechanical Demands of the Hang Power Clean and Jump Shrug: A Joint-Level Perspective.

Kipp, K, Malloy, PJ, Smith, J, Giordanelli, MD, Kiely, MT, Geiser, CF, and Suchomel, TJ. Mechanical demands of the hang power clean and jump shrug: a joint-level perspective. J Strength Cond Res 32(2): 466-474, 2018-The purpose of this study was to investigate the joint- and load-dependent changes in the mechanical demands of the lower extremity joints during the hang power clean (HPC) and the jump shrug (JS). Fifteen male lacrosse players were recruited from a National Collegiate Athletic Association DI team, and completed 3 sets of the HPC and JS at 30, 50, and 70% of their HPC 1 repetition maximum (1RM HPC) in a counterbalanced and randomized order. Motion analysis and force plate technology were used to calculate the positive work, propulsive phase duration, and peak concentric power at the hip, knee, and ankle joints. Separate 3-way analysis of variances were used to determine the interaction and main effects of joint, load, and lift type on the 3 dependent variables. The results indicated that the mechanics during the HPC and JS exhibit joint-, load-, and lift-dependent behavior. When averaged across joints, the positive work during both lifts increased progressively with external load, but was greater during the JS at 30 and 50% of 1RM HPC than during the HPC. The JS was also characterized by greater hip and knee work when averaged across loads. The joint-averaged propulsive phase duration was lower at 30% than at 50 and 70% of 1RM HPC for both lifts. Furthermore, the load-averaged propulsive phase duration was greater for the hip than the knee and ankle joint. The joint-averaged peak concentric power was the greatest at 70% of 1RM for the HPC and at 30%-50% of 1RM for the JS. In addition, the joint-averaged peak concentric power of the JS was greater than that of the HPC. Furthermore, the load-averaged peak knee and ankle concentric joint powers were greater during the execution of the JS than the HPC. However, the load-averaged power of all joints differed only during the HPC, but was similar between the hip and knee joints for the JS. Collectively, these results indicate that compared with the HPC the JS is characterized by greater hip and knee positive joint work, and greater knee and ankle peak concentric joint power, especially if performed at 30 and 50% of 1RM HPC. This study provides important novel information about the mechanical demands of 2 commonly used exercises and should be considered in the design of resistance training programs that aim to improve the explosiveness of the lower extremity joints.

Reactive Strength Index Modified Is a Valid Measure of Explosiveness in Collegiate Female Volleyball Players.

The purpose of this study was to investigate the validity of the reactive strength index modified (RSImod) as a measure of lower body explosiveness. Fifteen female, National Collegiate Athletic Association Division I volleyball players performed vertical countermovement jumps (CMJs) while standing on a force plate. Each player performed 3 CMJs. The vertical ground reaction forces collected during each jump were used to calculate jump height, time to take-off, time to peak force, peak force, peak rate of force development, and peak power; the latter 3 variables were all normalized to body mass. Reactive strength index modified was calculated as the ratio between jump height and time to take-off. All variables, except for jump height, were then entered a factor analysis, which reduced the input data into 2 factors: a force factor and a speed factor. Although RSImod loaded more strongly onto the force factor, further analysis showed that RSImod loaded positively onto both force and speed factors. Visual analysis of the Cartesian coordinates also showed that RSImod loaded into the quadrant of greater force and speed abilities. These results indicate that the construct of RSImod, as derived from CMJ force-time data, captures a combination of speed-force factors that can be interpreted as lower body explosiveness during the CMJ. Reactive strength index modified therefore seems to be a valid measure to study lower body explosiveness.

Time on wait lists for coronary bypass surgery in British Columbia, Canada, 1991-2000.

BACKGROUND: In British Columbia, Canada, all necessary medical services are funded publicly. Concerned with growing wait lists in the mid-1990s, the provincial government started providing extra funding for coronary artery bypass grafting (CABG) operations annually. Although aimed at improving access, it is not known whether supplementary funding changed the time that patients spent on wait lists for CABG. We sought to determine whether the period of registration on wait lists had an effect on time to isolated CABG and whether the period effect was similar across priority groups. METHODS: Using records from a population-based registry, we studied the wait-list time before and after supplementary funding became available. We compared the number of weeks from registration to surgery for equal proportions of patients in synthetic cohorts defined by five registration periods in the 1990s. RESULTS: Overall, 9,231 patients spent a total of 137,126 person-weeks on the wait lists. The time to surgery increased by the middle of the decade, and decreased toward the end of the decade. Relative to the 1991-92 registration period, the conditional weekly probabilities of undergoing surgery were 30% lower among patients registered on the wait lists in 1995-96, hazard ratio (HR) = 0.70 (0.65-0.76), and 23% lower in 1997-98 patients, HR = 0.77 (0.71-0.83), while there were no differences with 1999-2000 patients, HR = 0.94 (0.88-1.02), after adjusting for priority group at registration, comorbidity, age and sex. We found that the effect of registration period was different across priority groups. CONCLUSION: Our results provide evidence that time to CABG shortened after supplementary funding was provided on an annual basis to tertiary care hospitals within a single publicly funded health system. One plausible explanation is that these hospitals had capacity to increase the number of operations. At the same time, the effect was not uniform across priority groups indicating that changes in clinical practice should be considered when adding extra funding to reduce wait lists.

Use of physiologic pacing after the Canadian trial of physiologic pacing.

The Canadian trial of physiologic pacing (CTOPP), published in 2000, demonstrated a reduction in atrial fibrillation (AF), stroke and death with preservation of atrioventricular synchrony, though only the lower rate of AF was statistically significant. The purpose of this study was to determine the effect of CTOPP on pacing mode selection in our region. The British Columbia Cardiac Registry contains prospectively entered data covering a population of 4 millions (M) and 17 implanting centers. It was examined for mode selection trends from 1997 to 2002. At examination, there were data on 22,446 pulse generators (PG) and 29,898 leads. New implant rates per M population were 1997:473; 1998:456; 1999:505; 2000:513; 2001:486; 2002:510. PG replacements also increased, resulting in a total implant rate of 667 PG per M in 2002. Over the 6-year period, DDD use decreased from 321 to 306, but DDDR use, more than doubled from 317 to 750 PG/year. VVI use steadily decreased from 741 to 410 PG/year, while VVIR use increased more modestly from 1997 to 1999, then remained stable. During the 6-year period bracketing CTOPP, use of modes maintaining AV synchrony increased by over 32%, to 53% of PG implanted in 2002. Our PG implant rate was much higher than expected from prior retrospective surveys, and similar to rates in Belgium, France, and Germany. CTOPP did not decrease our use of physiologic pacing but, instead, was associated with a brief pause, then progressively increased in both academic and community centers. Patients' need and widely accepted standards of care proved more important in clinical decision making than the results of a flawed randomized trial.

Population rates of invasive cardiac procedures in British Columbia, 1995 to 2001.

BACKGROUND: This study examined the rates of coronary angiography (CA), percutaneous coronary intervention (PCI) and coronary artery bypass graft surgery (CABG) in British Columbia (BC) between 1995 and 2001. METHODS: Data sources were as follows: CABG--BC Cardiac Registries; CA and PCI--BC Medical Services Plan; acute coronary syndromes (ACS)--Hospital Separation database; population data--BC Statistics. All rates were age and sex standardized per 100,000 BC resident adults over 20 years of age. RESULTS: The rate of diagnostic CA increased from 352 per 100,000 in 1995 to 400 per 100,000 in 2001 (P<0.01). The rate of PCI increased from 101 per 100,000 in 1995 to 154 per 100,000 in 2001 (P<0.01). Single stage 'ad hoc' PCI increased from 38% in 1995 to 68% in 2001. The rate of CABG remained stable at between 70 and 79 per 100,000. There was a downward trend in the annual hospitalized incidence of ACS (477 to 430 per 100,000, P=0.04). The incidence of ACS and the rates of CA, PCI and CABG were higher for men in all age groups. PCI was more common than CABG in all groups. CONCLUSIONS: The incidence of ACS in BC is falling. The rates of diagnostic CA and PCI are increasing. The latter finding may reflect an appropriate evidence-based response to data supporting greater application of CA following ACS after publication of several studies supporting a routine invasive approach. The PCI rate is rising compared with the CABG rate, likely reflecting changes in patient selection and improved PCI technology, as well as a limited ability of the system to provide surgical procedures.

Clinical, magnetic resonance imaging, and electroencephalographic findings in paraneoplastic limbic encephalitis.

OBJECTIVE: To analyze clinical presentation of and paraclinical test abnormalities in patients with paraneoplastic limbic encephalitis (PLE). PATIENTS AND METHODS: We retrospectively reviewed 24 patients seen at the Mayo Clinic in Rochester, Minn, between 1985 and 2002 in whom PLE was suspected. Patients were identified on the basis of clinical history and presence of cancer. Data were reviewed from magnetic resonance imaging (MRI), cerebrospinal fluid (CSF) analysis, electroencephalography (EEG), and paraneoplastic serologic studies. RESULTS: Common manifestations were cognitive dysfunction (92%), seizures (58%), and psychiatric symptoms (50%); 13 patients had small cell lung carcinoma; 11 had other malignancies. Paraneoplastic neuronal autoantibodies were found in 14 (64%) of 22 patients tested. Electroencephalography showed focal or generalized slowing and/or epileptiform activity, maximal in the temporal regions, in all 22 patients tested. Magnetic resonance imaging revealed increased T2 signal involving one or both temporal lobes in 15 (83%) of 18 patients. Cerebrospinal fluid test results were abnormal in 18 (78%) of 23 patients tested. Clinical or radiographic evidence of extralimbic involvement was documented in 12 (55%) of 22 patients. No abnormality on EEG, MRI, or CSF analysis correlated with a specific cancer type or with a specific paraneoplastic autoantibody. CONCLUSIONS: In patients with suspected PLE, EEG is invaluable for confirming cerebral dysfunction. Magnetic resonance imaging can show unequivocal involvement of temporolimbic structures and helps exclude other diagnoses. When EEG and cranial MRI are both normal, PLE is unlikely. Comprehensive testing for paraneoplastic neuronal nuclear, cytoplasmic, and ion channel autoantibodies is an important part of the evaluation, but negative results do not rule out PLE.