The association between eccentric hip abduction strength and hip and knee angular movements in recreational male runners: An explorative study

Weak hip abductors may be related with increased hip adduction and knee abduction angular movement, which may be risk factors of lower extremity injuries. As the role of eccentric hip abduction strength (EHAS ) on hip adduction angular movement and knee abduction angular movement (KABD ) remains unclear, the purpose of this study was to explore the association between EHAS and hip and knee angular movement. In 100 healthy male recreational runners, EHAS was quantified using an isokinetic dynamometer, while hip and knee angular movements were collected using pressure‐sensitive treadmill and Codamotion active marker system. Using multiple linear regression models (n=186 legs), no relationships between EHAS and hip and knee kinematics were found. A possible reason for the lack of relationship between EHAS and hip and knee kinematics may be owing to differences in the running kinematics. Some runners with weak EHAS may compensate the weakness by leaning toward the stance limb and thereby reduces the demand on the hip abductors with the consequence of increased knee abduction moment, which may lead to an increased knee abduction angular excursion. Possible, others mechanism as the quadriceps strength and activity in the hip and thigh muscles may also be able to explain the lack of relationship that may or may not exist. Despite the inconclusive results of this study, the findings may suggest that weak hip abductor muscles may be a relevant factor to focus on in future studies.     

Hip strength assessment using handheld dynamometry is subject to intertester bias when testers are of different sex and strength

Handheld dynamometry (HHD) is a promising tool for obtaining reliable hip strength measurements in the clinical setting, but intertester reliability has been questioned, especially in situations where testers exhibit differences in upper‐extremity muscle strength (male vs female). The purpose of this study was to examine the intertester reliability concerning strength assessments of hip abduction, adduction, external and internal rotation, flexion and extension using HHD, and to test whether systematic differences in test values exist between testers of different upper‐extremity strength. Fifty healthy individuals (29 women), aged 25 ± 5 years were included. Two physiotherapist students (one female, one male) of different upper‐extremity strength performed the measurements. The tester order and strength test order were randomized. Intraclass correlation coefficients were used to quantify reliability, and ranged from 0.82 to 0.91 for the six strength test. The female tester systematically measured lower strength values for all isometric strength tests (P < 0.05). In hip strength assessments using HHD, systematic bias exists between testers of different sex, which is likely explained by differences in upper‐extremity strength. Hence, to improve intertester reliability, the dynamometer likely needs external fixation, as this will eliminate the influence of differences in upper‐extremity strength between testers.     

The clinical assessment of hip muscle strength in professional rugby union players

Groin/hip injuries are prevalent in rugby union (RU). Assessment of hip muscle strength is important when designing bespoke injury prevention and rehabilitation programmes.ObjectiveThe primary aim of this study was to determine normative values of hip muscle strength in elite-level RU players. A secondary aim of this study was to compare the Copenhagen Hip and Groin Outcome Score (HAGOS) between players with and without a history of groin/hip injury.DesignCross-sectional cohort study.SettingProfessional RU club.Participants58 male professional RU players competing in the PRO14 league elite club level competition.Main outcome measuresHandheld dynamometry eccentric strength values of hip abduction (ABD), adduction (ADD), internal rotation (IR) and external rotation (ER), HAGOS.ResultsPlayers' dominant (DOM) and non-dominant (NDOM) hip strength values were, 2.38 and 2.34 N m/kg for ABD, 2.79 and 2.71 N m/kg for ADD, 2.69 and 2.55 N m/kg for IR, and 2.65 and 2.54 N m/kg for ER. ADD:ABD strength ratio was 1.17 ± 0.26 for the DOM limb and 1.16 ± 0.24 for the NDOM limb. There was no clinically significant difference in strength between players’ DOM and NDOM limbs. Players with a history of groin/hip injury scored lower on four of the HAGOS subscales (pain; symptoms; sport; quality of life) compared to those without a history of groin/hip injury.ConclusionsThis study may help establish normative hip strength and HAGOS values for elite-level RU players. The results presented have important implications for the assessment of hip muscle strength and could provide clinical markers for return-to-play following injury.     

In hip osteoarthritis,Nordic Walking is superior to strength training and home‐based exercise for improving function

This observer‐blinded, randomized controlled trial compared the short‐ and long‐term effects of 4 months of supervised strength training (ST) in a local fitness center, supervised Nordic Walking (NW) in a local park, and unsupervised home‐based exercise (HBE, control) on functional performance in 60+‐year‐old persons (n = 152) with hip osteoarthritis (OA) not awaiting hip replacement. Functional performance [i.e., 30‐s chair stand test (primary outcome), timed stair climbing, and 6‐min walk test] and self‐reported outcomes (i.e., physical function, pain, physical activity level, self‐efficacy, and health‐related quality of life) were measured at baseline and at 2, 4, and 12 months. Based on intention‐to‐treat‐analyses improvements [mean (95% CI)] after intervention in number of chair stands were equal in all three groups at 4 months [ST: 0.9 (0.2–1.6), NW: 1.9 (0.8–3.0), HBE: 1.1 (0.1–2.0)] but greater in the NW group [1.4 (0.02–2.8)] than in the ST group at 12 months. Generally, improvements in functional performance were greater (P < 0.001–P < 0.03) after NW compared with HBE and ST at all follow‐up time points. Furthermore, NW was superior (P < 0.01) to HBE for improving vigorous physical activity and to both ST and HBE for improving (P < 0.01) mental health. These data suggest that NW is the recommended exercise modality compared with ST and HBE.     

T1 assessment of hip joint cartilage following intra‐articular gadolinium injection: A pilot study

This pilot study defines the feasibility of cartilage assessment in symptomatic femoroacetabular impingement patients using intra‐articular delayed gadolinium‐enhanced MRI of cartilage (ia‐dGEMRIC). Nine patients were scanned preliminary to study the contrast infiltration process into hip joint cartilage. Twenty‐seven patients with symptomatic femoroacetabular impingement were subsequently scanned with intra‐articular delayed gadolinium‐enhanced MRI of cartilage. These T₁ findings were correlated to morphological findings. Zonal variations were studied. This pilot study demonstrates a significant difference between the pre‐ and postcontrast T₁ values (P < 0.001) remaining constant for 45 min. We noted higher mean T₁ values in morphologically normal‐appearing cartilage than in damaged cartilage, which was statistically significant for all zones except the anterior‐superior zone. Intraobserver (0.972) and interobserver correlation coefficients (0.933) were statistically significant. This study outlines the feasibility of intra‐articular delayed gadolinium‐enhanced MRI of cartilage for assessment of cartilage changes in patients with femoroacetabular impingement. It can also define the topographic extent and differing severities of cartilage damage. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.     

Sports and physical activity after cementless total hip arthroplasty with a minimum follow‐up of 10 years

The present retrospective cohort study was conducted to compare sporting activity levels before and a minimum of 10 years after primary cementless total hip arthroplasty (THA). A consecutive series of 86 patients with a mean age at surgery of 52 years (range, 21–60 years) was evaluated 11 years after surgery (range, 10–12 years). Pre‐ and post‐operative sporting activities were assessed at routine follow‐up using the University of California, Los Angeles activity score and the Schulthess Clinic sports and activity questionnaire. Post‐operative health‐related quality of life was measured using the Short‐Form 36 (SF‐36) questionnaire and compared with age‐matched reference populations from the SF‐36 database. Eleven years after THA, 89% of preoperatively active patients had returned to sport. Comparing sports activity preoperatively (before the onset of symptoms) and 11 years after THA, no significant difference was found for the mean number of disciplines or session length. A significant decline in high‐impact activities was observed, while participation in low‐impact activities significantly increased. Health‐related quality of life compared well against a healthy age‐matched reference population and was significantly higher than in a reference group of patients with osteoarthritis. The majority of patients were able to maintain their physical activity level in the long term after primary cementless THA, compared with the activity level before the onset of restricting osteoarthritis symptoms. However, a change in disciplines toward low‐impact activities was observed.     

Arthroscopic assessment of total hip replacement and polyethylene wear: a case report

We report the case of a patient who showed clinical and radiological signs of massive polyethylene wear 3 years after total hip replacement. Arthroscopy was performed to assess the loosening of the acetabular cup. The procedure showed the polyethylene element to be broken into three pieces in the area corresponding to the upper border. Received: 18 December 1998 Accepted: 25 November 1999     

Excellent reliability of toe strength measurements in children aged ten to twelve years achieved with a novel fixed dynamometer

BackgroundStronger toe flexor muscles improve performance outcomes in children, including balance, sprinting, jumping and side stepping. Toe flexor strength (TFS) is recommended as part of the clinical assessment of foot function in children. Fixed dynamometry, rather than handheld, is the gold standard of measurement; however, it can be prohibitively costly. No fixed dynamometer reliability studies on toe flexion have been conducted in children to date.Research questionsDoes the novel fixed hand-held dynamometer (HHD) protocol provide reliable intra-rater and test-retest measurements of toe flexor strength in children aged 10 to 12?MethodsTwo trials were recorded from 14 healthy children (10–12 years), 7–14 days apart by the same rater. A Lafayette HHD (model 01163) measured peak force. The HHD was secured in a mobile custom mould below a step with a strap, which secured the foot of the participant. The receptor pads of the HHD were level with the upper surface of the step, maintaining neutral toe joints at rest. The participant was seated on an adjustable stool to ensure the hip, knee and ankle were each at 90° flexion, with the testing foot flat on the upper surface of the step. The averages of three maximal five second efforts were used for data analysis using a two-way mixed effects model with repeated measures ANOVA (intraclass correlation coefficient ICC 3,3). Standard error of measurement (SEM) was calculated to determine the absolute between trial variability.ResultsThe novel fixed HHD protocol provided excellent test-retest reliability with small measurement error for hallux (ICC 3,3 = 0.93, 95 % CI 0.78−0.98, SEM = 4.31 N) and lesser toe flexor strength testing (ICC 3,3 = 0.96, 95 % CI 0.87−0.99, SEM = 1.86 N).SignificanceThe fixed HHD protocol described in this study has excellent reliability for the test-retest evaluation of children’s toe flexor strength.     

Feasibility of T mapping for the evaluation of hip joint cartilage at 1.5T using a three‐dimensional (3D), gradient‐echo (GRE) sequence: A prospective study

This study defines the feasibility of utilizing three‐dimensional (3D) gradient‐echo (GRE) MRI at 1.5T for T mapping to assess hip joint cartilage degenerative changes using standard morphological MR grading while comparing it to delayed gadolinium‐enhanced MRI of cartilage (dGEMRIC). MRI was obtained from 10 asymptomatic young adult volunteers and 33 patients with symptomatic femoroacetabular impingement (FAI). The protocol included T mapping without gadolinium‐enhancement utilizing a 3D‐GRE sequence with six echoes, and after gadolinium injection, routine hip sequences, and a dual‐flip‐angle 3D‐GRE sequence for dGEMRIC T₁ mapping. Cartilage was classified as normal, with mild changes, or with severe degenerative changes based on morphological MRI. T₁ and T findings were subsequently correlated. There were significant differences between volunteers and patients in normally‐rated cartilage only for T₁ values. Both T₁ and T values decreased significantly with the various grades of cartilage damage. There was a statistically significant correlation between standard MRI and T (T₁) (P < 0.05). High intraclass correlation was noted for both T₁ and T. Correlation factor was 0.860 to 0.954 (T‐T₁ intraobserver) and 0.826 to 0.867 (T‐T₁ interobserver). It is feasible to gather further information about cartilage status within the hip joint using GRE T mapping at 1.5T. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.     

Measurement properties of handheld dynamometry for assessment of shoulder muscle strength: A systematic review

Like any assessment tool, handheld dynamometry (HHD) must be valid and reliable in order to be meaningful in clinical practice and research. To summarize the evidence of measurement properties of HHD for the assessment of shoulder muscle strength. Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, EMBASE, and PEDro were searched up to February 2020. Inclusion criteria were studies (a) evaluating HHD used on the glenohumeral joint, (b) evaluating measurement properties, and (c) included individuals ≥ 18 years old with or without shoulder symptoms. Exclusion criteria were studies (a) including patients with neurologic, neuromuscular, systemic diseases, or critical illness or bed-side patients and (b) that did not report the results separately for each movement. In total, 28 studies with 963 participants were included. The reliability results showed that 98% of the intraclass correlation coefficient (ICC) values were ≥0.70. The measurement error showed that the minimal detectable change in percent varied from 0% to 51.0%. The quality of evidence was high or moderate for the majority of movements and type of reliability examined. Based on the evidence of low or very low quality of evidence, the convergent validity and discriminative validity of HHD were either sufficient, indeterminate, or insufficient. The reliability of HHD was overall sufficient, and HHD can be used to distinguish between individuals on the group level. The measurement error was not sufficient, and evaluation of treatment effect on the individual level should be interpreted with caution.     

Trunk muscle strength and lumbo‐pelvic kinematics in adolescent athletes: Effects of age and sex

Considering their potential relevance for low‐back pain, we investigated trunk muscle strength, sagittal lumbo‐pelvic alignment while standing and lumbo‐pelvic ratio during trunk flexion in adolescent athletes with regard to the effects of age and sex. Twenty‐two early adolescent (EA: 13‐15 years, 10 females) and 28 late adolescent (LA: 16‐19 years, 14 females) high‐level athletes (training duration more than 12 hours per week) participated in the study. We measured trunk extension and trunk flexion moments during maximum voluntary isometric contractions using a dynamometer. Further, we examined lumbo‐pelvic kinematics in the upright standing position and during forward trunk bending using two 3‐dimensional accelerometers. Using a lineal regression model in which the flexion moment from each participant was used as predictor for the corresponding extension moment, we found higher residuals (P < 0.001) in the EA compared to LA, indicating greater imbalances in the trunk muscle strength in EA. We found a higher lordosis in the upright position, greater pelvic rotation, and greater lordotic posture during the forward bending in females (P < 0.01). These age‐related imbalances and sex‐related characteristics in lumbo‐pelvic kinematics might affect the neuromuscular control of trunk stability and the magnitude of spine loading. We recommend the implementation of specific coordination and stabilization programs for muscle groups that contribute to lumbo‐pelvic kinematics and training routines that support a balanced strength development within the trunk muscles in adolescent athletes.     

Prevalence and severity of hip and groin pain in sub‐elite male football: a cross‐sectional cohort study of 695 players

The purpose of this study was twofold: (a) to investigate the prevalence of hip and groin pain in sub‐elite male adult football in Denmark and (b) to explore the association between prevalence and duration of hip and groin pain in the previous season with the Copenhagen Hip and Groin Outcome Score (HAGOS) in the beginning of the new season. In total 695 respondents from 40 teams (Division 1–4) were included. Players completed in the beginning of the new season (July–Sept 2011) a self‐reported paper questionnaire on hip and/or groin pain during the previous season and HAGOS. In total 49% (95% CI: 45–52%) reported hip and/or groin pain during the previous season. Of these, 31% (95% CI: 26–36%) reported pain for >6 weeks. Players with the longest duration of pain during the previous season had the lowest HAGOS scores, when assessed at the beginning of the new season, P < 0.001. This study documents that half of sub‐elite male adult football players report pain in the hip and/or groin during a football season. The football players with the longest duration of pain in previous season displayed the lowest HAGOS scores in the beginning of the new season.     

Velocity‐specific and time‐dependent adaptations following a standardized Nordic Hamstring Exercise training

The Nordic Hamstring Exercise (NHE ) is effective for selective hamstring strengthening to improve muscle balance between knee flexors and extensors. The purpose of this study (within subject design of repeated measures) was to determine the effects of a standardized 4‐week NHE training on thigh strength and muscle balance with concomitant kinetic and kinematic monitoring. Sixteen male sprinters (22 years, 181 cm, 76 kg) performed a standardized 4‐week NHE training consisting of three sessions per week (each 3×3 repetitions). Six rope‐assisted and six unassisted sessions were performed targeting at a constant knee extension angular velocity of ~15°/s across a ~90‐100° knee joint range of motion. Kinetic (peak and mean moment, impulse) and kinematic parameters (eg, ROM to downward acceleration, ROM_DWA ) were recorded during selected sessions. Unilateral isokinetic tests of concentric and eccentric knee flexors and extensors quantified muscle group‐, contraction mode‐, and velocity‐specific training adaptations. Peak moments and contractional work demonstrated strong interactions of time with muscle group, contraction modes, and angular velocities (η²>.150). NHE training increased eccentric hamstring strength by 6%‐14% as well as thigh muscle balance with biggest adaptations at 150°/s 2 weeks after NHE training. Throughout the training period significant increases (P <.001) of peak (η²=.828) and mean moments (η²=.611) became apparent, whereas the impulse and the ROM_DWA of unassisted NHE repetitions remained unchanged (P >.05). A 4‐week NHE training significantly strengthened the hamstrings and improved muscle balance between knee flexors and extensors. Despite the slow training velocity, biggest adaptations emerged at the highest velocity 2 weeks after training ended.     

BTrackS limits of stability test is a reliable assessment of volitional dynamic postural control

BackgroundUnconstrained limits of stability assessment reveals aspects of volitional postural sway control that are inaccessible by other means. Prior versions of this assessment include instructions to sway towards predefined targets, and may not capture the full capability of the individual.Research questionThis study sought to establish the test-retest reliability of a novel limits of stability protocol.MethodsVolitional sway area was determined during unconstrained trials, where participants were instructed to explore their ability to sway towards the perimeter of their base of support. Visual feedback was provided via computer monitor. Forty healthy young adults (mean age = 20.2 ± 1.3, 15 males, 25 females) participated in this study. Trials were collected in three sessions, repeated at the same time of the same day, with one week between. Reliability was assessed using IntraClass Correlation Coefficients (ICC), considering the total area of sway as well as quadrant level area.ResultsReliability was moderate between the first and second session (0.583), and much higher 0.921) between the second and third session. The quadrant level reliability was poor to excellent (0.183−0.791), with similar trends between the three sessions.SignificanceUltimately, these results indicate that the novel limits of stability test is reliable. However, it is recommended that a practice trial be conducted prior to baseline establishment.     

The concurrent validity and intrarater reliability of a hand-held dynamometer for the assessment of neck strength in semi-professional rugby union players

ObjectivesThe main objective of this study was to determine the concurrent validity between a hand-held (HHD) and mounted hand-held dynamometer (MHHD) for assessing isometric neck strength.DesignObservational design.SettingSemiprofessional rugby club.ParticipantsNineteen semi-professional rugby players (age = 26 ± 5 years, stature = 186.5 ± 6.5 cm, body mass = 98.7 ± 12.8 kg).Main outcome measuresConcurrent validity (limits of agreement, correlation) between HHD and MHHD, the intrarater reliability (intra-class correlation, ICC) and comparison between playing positions.ResultsAbsolute peak and mean peak force were systematically lower when using the HHD compared to MHHD, with the mean bias ranging from −1.8 to −3.8 kgf (P < 0.05). Differences were not evident for flexion when applying the correction equations (−0.5 to 2.1 kgf, P > 0.05) but remained for extension. Correlations between methods were large-to-very large; the ICCs for both methods were good (ICC = 0.72–0.89), with no difference between positions (P < 0.05).ConclusionThe concurrent validity of HHD was considered acceptable when compared to the MHHD and the correction equation applied. Both methods are reliable and useful for assessing neck strength in rugby players, though, caution is needed when determining strength during neck extension.     

手术导航系统提高全髋关节置换术中髋臼假体植入精确度的研究

目的　评价应用新型非影像手术导航系统进行非骨水泥全髋关节置换对提高术中髋臼假体植入角度精确度的影响。　方法　取 12具成人尸体 ,每例随机于一侧应用手术导航系统进行全髋关节置换髋臼假体植入 ,其对侧用传统的髋臼假体定位器植入假体。设定髋臼假体最佳植入角度为倾斜角 4 5°,前倾角 2 0°。术后用三维数字化仪测定髋臼假体植入的角度情况。　结果　手术导航系统植入的髋臼假体倾斜角为 (4 5 .5± 2 .3)°,前倾角为 (2 1.8± 2 .5 )°。传统方法植入假体的倾斜角为 (4 2 .5± 6 .3)° ,前倾角为 (2 4 .8± 7.7)°。比较两组结果 ,倾斜角的差异具有显著性意义 (P <0 .0 5 )。　结论　手术导航系统可以很好地提高术中髋臼假体植入的精确度 ,从而降低假体松动等并发症的发生。     

Kinematic,strength, and stiffness adaptations after a short‐term sled towing training in athletes

One of the most frequently used methods for training the sprint‐specific strength is the sled towing. To date, no studies have been conducted to explore the effects of this method after a training period in well‐trained athletes. The purpose of this study was to determine the effects of 4 weeks of resisted sprint training with sled towing. Twenty‐two trained athletes experienced in the use of weighted sled (WS) participated in the study. They conducted the same 3‐week training to level their initial condition. After that they were distributed in two groups, unresisted (UR) and WS training. They carried out the same 4‐week, 2 days/week sprint‐specific training, only differing in that the experimental group performed sprints with a (WS) which caused a reduction of 7.5% of their maximum velocity. Pre‐ and posttest were conducted which included the measurement of sprint kinematics, muscular strength (including isoinertial, isokinetic, and jump measurements), and sprinting stiffness (leg and vertical). Results show different adaptations in the groups although no interaction effect was found. The WS group improved the velocity in the transition phase, while the UR group improved the velocity in the maximum velocity phase. No improvements in the height of the jump tests were found.     

Effects of contract‐relax vs static stretching on stretch‐induced strength loss and length–tension relationship

The purpose of this study was to determine the acute effects of contract‐relax stretching (CRS) vs static stretching (SS) on strength loss and the length‐tension relationship. We hypothesized that there would be a greater muscle length‐specific effect of CRS vs SS. Isometric hamstring strength was measured in 20 healthy people at four knee joint angles (90°, 70°, 50°, 30°) before and after stretching. One leg received SS, the contralateral received CRS. Both stretching techniques resulted in significant strength loss, which was most apparent at short muscle lengths [SS: P = 0.025; stretching × angle P < 0.001; 11.7% at 90° P < 0.01; 5.6% at 70° nonsignificant (ns); 1.3% at 50° ns; ?3.7% at 30° ns. CRS: P < 0.001; stretching × angle P < 0.001; 17.7% at 90°, 13.4% at 70°, 11.4% at 50°, all P < 0.01, 4.3% at 30° ns]. The overall stretch‐induced strength loss was greater (P = 0.015) after CRS (11.7%) vs SS (3.7%). The muscle length effect on strength loss was not different between CRS and SS (stretching × angle × stretching technique P = 0.43). Contrary to the hypothesis, CRS did not result in a greater shift in the length–tension relationship, and in fact, resulted in greater overall strength loss compared with SS. These results support the use of SS for stretching the hamstrings.