Flexion Power Research Articles

Differences in Trunk Strength Between Weightlifters and Wrestlers.

Investigations of trunk strength with high-level athletes are limited. The purpose of this study was to compare maximal concentric isokinetic trunk extension and flexion torque, power, and strength ratios between high-level weightlifters (n = 20), wrestlers (n = 20) and a control (n = 25) population. Isokinetic dynamometry was used to evaluate peak torque, power and strength ratios during seated trunk extension/flexion actions at 60°/s and 180°/s. There were no significant anthropometric differences between groups. Overall, trunk isokinetic force variables as a function of the increase in angular velocity, showed a decrease in peak torque, but an increase in power (athletes and controls). Compared to the control group, athletes demonstrated significantly higher trunk extension torque (+67.05 N·m, ES = 0.81) and power (+49.28 N·m, ES = 0.82) at 60°/s and 180°/s, respectively. Athletes produced significantly greater trunk flexion-extension ratios at 60°/s and 180°/s (ES = 0.80-0.47) than controls. Weightlifters and wrestlers exhibited significantly higher extensor than flexor torque at all angular velocities. Weightlifters demonstrated greater torque (ES = 0.79) than wrestlers at 60°/s. The wrestlers’ average power was significantly higher (ES = 0.43) than weightlifters at 180°/s. There were no significant ratio differences between wrestlers (66.23%) and weightlifters (72.06%). Weightlifters had stronger extensor muscles at 60°/s, whereas wrestlers had higher power at 180°/s for extensor muscles. It was postulated that the extensor muscles were stronger than the flexors to ensure trunk stabilisation, and for prevention of injuries. These differences seem to be associated to the movements that occur in each sport in terms of both muscle actions and contractile forces.

Effect Of Ballet Dance On Knee Joints Muscle Strength Based On The Isokinetic Research

PURPOSE: Several researches have revealed that dance training increases muscle strength. By comparing the muscle strength of knee joints of ordinary college students with ballet dance students', the differences between the two groups were analyzed and the influence of dance on muscle strength was explained. METHODS: 48 healthy college students volunteered to participate in the study. Experimental group consisted of 24 Ballet students (12 male, 21.5±0.9years; 12 female, 20.9±1.8years); control group consisted of 24 non-dance students (12male, 20.7±0.9years, 12 female, 20.6±0.8years). German ISOMED2000 Isokinetic test device was used to test the knee joints strength of all participants, with the concentric contraction test going first and then following the eccentric contraction test , with the testing angular of 60°/s,180°/s .The test variables include peak torque,relative peak torque and the peak torque ratio of flexion and extension. RESULTS: The result showed that the female and male Ballet students have significantly higher peak torque (N·m )and relative peak torque (Nm/Kg) at all angular of knee flexion and extension than non-dance students (All peak torque flexion at 60°/s and 180°/s: 81.805±10.84 vs. 58.725±7.34 and 68.055±9.22 vs.46.875±8.78; both p<0.01. All peak torque extension at 60°/s and 180°/s: 178.335±25.88 vs. 124.2±19.54 and 128.465±14.96 vs. 92.505±16.41; both p<0.01. All relative peak torque flexion at 60°/s and 180°/s:1.29±0.14 vs. 1.02±0.14 and 1.08±0.14 vs.0.81±0.13;both p<0.01. All relative peak torque extension at 60°/s and 180°/s :2.84±0.43 vs.2.17±0.38 and 2.04 ±0.25 vs.1.61±0.28; both p<0.01.).However, there is no significant difference in peak torque ratio of flexion and extension between two groups (P>0.05). CONCLUSIONS: The results indicated that long-term ballet training can obviously improve the control strength and outbreak power of knee flexion and extension. Ballet training leads to a balanced effect impact on hamstring and quadriceps, which helps to avoid knee injuries and improve the dance movements. Acknowledgements: This work was supported by Beijing philosophy and social science foundation research (Grants No.14JDWYB011).

Validity of inertial measurement unit–based knee flexion strength-power test

This study aimed to examine the concurrent validity of inertial measurement unit–based knee flexion strength-power test variables. Ten physically active males performed a knee flexion strength-power test, consisting of serial right knee flexion-extension motions. Two trials were performed, each at 50%, 75% and 100% effort. Lower-extremity motion during the trial was recorded using a motion capture system and an inertial measurement unit. For inertial measurement unit data, the measured length of each lower-extremity segment was used to estimate segment endpoint coordinates. Knee flexion kinetic variables were then computed using inverse dynamics analysis for both systems. The inertial measurement unit provided comparable values with the motion capture system for angular impulse, mean moment, positive work and mean power (−0.8%, 1.0%, −0.9%, and 1.5%, respectively). Moreover, intraclass correlation coefficients and correlation coefficients for angular impulse, mean moment, positive work and mean power of knee flexion were acceptably high (ICC or r = 0.903–0.970). For positive mean power, however, a Bland–Altman plot showed heteroscedasticity. For knee flexion negative work and mean power, the inertial measurement unit clearly showed an overestimation of the values (32.5% and 23.5%, respectively). Moreover, the intraclass correlation coefficients and correlation coefficients were not acceptably high for knee flexion negative work and mean power (ICC or r = 0.541–0.899). These results indicate that the angular impulse, mean moment and positive work can be measured accurately and validly using an inertial measurement unit for knee flexion strength-power test variables. Given its simplicity, the suggested inertial measurement unit–based knee flexion strength-power test would improve on-the-field physical fitness evaluation.

Effects of moving cupping therapy on hip and knee range of movement and knee flexion power: a preliminary investigation

ABSTRACTCupping therapy has become more popular in the sports setting because of its simplicity in application, minimal adverse effects, and reduction in pain and muscle tenderness, yet there is little research on its effectiveness for range of movement and power.Objectives: The primary aim of this study was to investigate if a single session of moving cupping to the posterior aspect of the lower limb effects hip and knee range of movement and knee flexion power. The secondary aim was to consider participants’ views and perceptions of moving cupping therapy.Methods: Twenty-one healthy participants (12 male and 9 female) aged between 19 and 31 years volunteered to take part in the study. All participants received 15 min of moving cupping therapy to their dominant posterior lower extremity. Hip and knee range of movement and knee flexion isokinetic power measurements were taken prior to and immediately after the moving cupping intervention. Participants also completed a questionnaire based on their experience and perceptions of cupping.Results: Results showed a significant increase (p = <.05) in hip and knee range of movement measurements by 7% in the straight leg raise and 4% in a popliteal angle test. However, no significant changes were seen in the knee flexion power measures. Data from the questionnaire suggest that despite moving cupping being reported as ‘uncomfortable’ it is considered acceptable.Discussion: Moving cupping therapy may have short-term changes to range of movement but not power, though the limitations of this study mean that rigorous studies are required before the effectiveness of moving cupping can be determined.

A systematic review on biomechanical characteristics of walking in children and adolescents with overweight/obesity: Possible implications for the development of musculoskeletal disorders.

It is known that obesity is associated with biomechanical alterations during locomotor tasks, which is considered a potential risk factor for the development of musculoskeletal disorders (MSKD). However, the association of obesity with biomechanical alterations of walking in the early stages of life have not yet been systematically reviewed. Thus, this review aims to summarize the biomechanical characteristics of walking in children and adolescents with overweight/obesity (OW/OB) versus their normal-weight (NW) counterparts. PubMed and Web of Science were systematically searched until November 2018. We found strong and moderate evidence supporting biomechanical differences in the gait pattern of OW/OB with respect to NW. Based on strong evidence, the gait patterns of OW/OB present greater pelvis transversal plane motion, higher hip internal rotation, higher hip flexion, extension and abduction moments and power generation/absorption, greater knee abduction/adduction motion, and higher knee abduction/adduction moments and power generation/absorption. Based on moderate evidence, OW/OB walk with greater step width, longer stance phase, higher tibiofemoral contact forces, higher ankle plantarflexion moments and power generation, and greater gastrocnemius and soleus activation/forces. These biomechanical alterations during walking in OW/OB could play a major role in the onset and progression of MSKD.

Flexor hallucis longus vs. peroneus brevis: the better tendon for augmentation surgery in chronic achilles tendon ruptures

&lt;p class="abstract"&gt;&lt;strong&gt;Background:&lt;/strong&gt; Chronic degenerative Achilles tendon ruptures are increasing in incidence. Calcific tendonitis, poor vascularity, prior steroid injections, and proximal migration of tendon render conservative management ineffective. Flexor hallucis longus (FHL) and peroneus brevis (PB) have shown promising results with tendon augmentation procedures. The study was done to find out which was a better tendon for augmentation among the two.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Methods:&lt;/strong&gt; A total of 27 patients underwent tendon augmentation surgeries using FHL (n=14) and PB (n=13) after randomization at PES Institute of medical sciences and research, Kuppam from March 2014 to December 2018. Both the groups had a standard postoperative regimen and rehabilitative protocol. Functional outcome was assessed using AOFAS, Leppilahti score and ATRS scores.&lt;strong&gt;&lt;/strong&gt;&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Results:&lt;/strong&gt; The functional outcome was comparable in both FHL and PB and there was no clear winner in the study.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Conclusions:&lt;/strong&gt; Predictably&lt;strong&gt; &lt;/strong&gt;good results are seen with tendon augmentation procedures for Achilles tendon rupture. Both FHL and PB are equally good in providing good plantar flexion power needed in achilles tendon rupture.&lt;/p&gt;

Effects of Eurycoma Longifolia Jack Supplementation Combined with Resistance Training on Isokinetic Muscular Strength and Power, Anaerobic Power, and Urinary Testosterone: Epitestosterone Ratio in Young Males.

Introduction:This study investigated the effects of resistance training and Eurycoma longifolia Jack supplementation on isokinetic muscular strength and power, Wingate anaerobic power, and testosterone: epitestosterone (T/E) ratio in young males.Methods:Forty young males were weight-matched and assigned into four groups: control (C), Eurycoma longifolia jack (ElJ), resistance training (RT), and Eurycoma longifolia Jack plus resistance training group (ElJ & RT). Participants in ElJ and ElJ & RT groups consumed 200 mg Eurycoma longifolia Jack daily, whereas participants in the C and RT groups consumed placebo capsules daily for 8 weeks. Resistance training program which consisted of 10 different exercises was conducted three times per week for 8 weeks. Participants' isokinetic muscular strength and power, anaerobic power, and urinary TE ratio were measured before and after the intervention period. This is a randomized placebo-controlled intervention study. Paired t-test and one-way analysis of variance were used for statistical analysis.Results:The mean average power of knee flexion at 300°/s in the RT and ElJ & RT groups was significantly (P < 0.05) higher in the posttest compared with pretest. Wingate relative peak power in the RT group increased significantly (P < 0.05) compared with respective pretest value, whereas peak power in the combined ElJ & RT group was significantly (P < 0.05) higher in posttest compared with pretest. There was no significant difference in T/E ratio between pre- and posttests in all the groups.Conclusions:The prescribed resistance training program, either with or without ElJ supplementation, improved isokinetic power of the lower limb. Resistance training alone improved relative anaerobic power, whereas combined Eurycoma longifolia Jack and resistance training improved peak power output. ElJ consumption of 200 mg daily for 8 weeks did not affect the urinary T/E ratio.

Foot orthoses alter lower limb biomechanics but not jump performance in basketball players with and without flat feet

BackgroundFlat-footed individuals are believed to have poorer jump performance compared to normal-arched individuals. Foot orthoses are commonly used to support the deformed foot arch, and improve normal foot function. However, it is unclear if foot orthoses use affects jump performance in athletes. Our study aims to investigate if foot type and/or foot orthosis influence countermovement jump (CMJ) and standing broad jump (SBJ) performance and lower limb biomechanics.MethodsTwenty-six male basketball players were classified into normal-arched (n = 15) or flat-footed (n = 11) groups using the Chippaux-Smirak index, navicular drop test, and the resting calcaneal angle measurement. They performed jumps with and without prefabricated foot orthoses. We measured jump height and distance for CMJ and SBJ, respectively. Hip, knee and ankle joint angles, angular velocities, moments and powers during take-off were also measured.ResultsFor CMJ, the flat-footed group exhibited less ankle plantarflexion (F1,24 = 8.407, p = 0.008, ηp2 = 0.259 large effect) and less hip joint power (F1,24 = 7.416, p = 0.012, ηp2 = 0.244 large effect) than the normal-arched group. Foot orthoses reduced ankle eversion in both groups (F1,24 = 6.702, p = 0.016, ηp2 = 0.218 large effect). For SBJ, the flat-footed group produced lower peak hip angular velocity (F1,24 = 7.115, p = 0.013, ηp2 = 0.229 large effect) and generated lower horizontal GRF (F1,24 = 5.594, p = 0.026, ηp2 = 0.189 large effect) than the normal-arched group. Wearing foot orthoses reduced ankle eversion (F1,24 = 5.453, p = 0.028, ηp2 = 0.185 large effect), peak horizontal GRF (F1,24 = 13.672, p = 0.001, ηp2 = 0.363 large effect) and frontal plane ankle moment (F1,24 = 4.932, p = 0.036, ηp2 = 0.170 large effect).ConclusionFoot type and the use of foot orthoses influence take-off biomechanics, but not actual CMJ and SBJ performances in basketball players. Compared to the normal-arched individuals, flat-footed athletes generated smaller propulsion GRF and lower hip flexion velocity and power, which suggests possible compensatory movement strategies to maximise jump performance. Future studies may investigate whether these altered biomechanics, taking into consideration their respective magnitude and effect sizes, may have implications on lower limb injuries. The use of foot orthoses resulted in biomechanical changes in both the normal-arched and flat-footed groups but does not enhance jumping performance.

Estimation of the ankle power during the terminal stance of gait using an inertial sensor.

[Purpose] The purpose of this study was to develop an assessment tool that reflects the ankle function during the terminal stance of gait using an inertial sensor. [Participants and Methods] Thirteen healthy males (20 limbs) participated in this study. All the participants were required to perform five straight-line walking trials along a 10-m level walkway. During the terminal stance phase, both the anterior-posterior and vertical accelerations were measured with an inertial sensor mounted on the fibular head. The Pythagorean theorem was used to calculate the acceleration vector. A three-dimensional gait analysis system was used for movement data acquisition. All statistical analyses were performed using IBM SPSS Statistics 24.0 for Windows. [Results] Results were obtained using the following multiple regression equation for the estimation of ankle plantar flexion power: Estimated Ankle Power=−4.689 + 0.269 × vertical acceleration + 0.104 × body weight. [Conclusion] Our novel method for gait analysis using an inertial sensor can assess the ankle power during the terminal stance phase of gait.

Quantitative assessment of elbow flexion by handheld dynamometry in brachial plexus palsy.

The purpose of this study was to assess the relative and absolute reliability of a handheld dynamometer when used for examining elbow flexion power in patients with brachial plexus palsy. The assessment of the intra-rater and inter-rater reliability coefficients for the handheld dynamometer was done using the stationary Kin-Com® dynamometer as the reference standard. We determined the measurement errors and checked the systematic biases of the handheld dynamometer. The inter-rater and intra-rater reliabilities of the handheld dynamometer had a very high intraclass correlation coefficient. The values of handheld dynamometer readings had a high correlation to Kin-Com® readings. The Medical Research Council grading was a comparatively inaccurate method for quantitative assessment of motor power. We conclude that a handheld dynamometer measurement is more precise and reliable than the Medical Research Council grading for measuring recovery of elbow flexion in patients with brachial plexus palsy. Level of evidence: III.

Does clinically measured ankle plantar flexor muscle strength or weakness correlate with walking performance in healthy individuals?

Muscle strength is usually measured using isometric hand-held dynamometers (HHDs) in the clinic. However, during functional activities, the muscle acts more dynamically. The aim of this study was to investigate the relation between clinically measured plantar flexor (PF) muscle strength (PFMS) and laboratory measurements of peak ankle plantar flexion power generation (APFPG), peak ankle moment (PAM), peak plantar flexion velocity (PFV) and mean gait velocity in healthy participants. The maximum PFMS on non-dominant sides in 18 able-bodied persons 23.88 (SD 3.55 years) was measured before (Pre-S) and after a stretching (Post-S) procedure (135 sec. × 13 rep. with 5 sec. rest) by using a HHD. The stretching procedure was used to generate temporary PF muscle weakness. Gait analysis was carried out for Pre-S and Post-S conditions. Normalized (by weight and height) and non-normalized HHD scores and differences for both conditions were correlated by Pearson correlation coefficient calculations (p< 0.05). Reduced PFMS (%23, p< 0.001) in Post-S, according to the HHD scores, has only a weak correlation with APFPG (r> 0.3, p< 0.5). Gait velocity was found to be strongly correlated with APFPG only in the Post-S condition (r= 0.68, p< 0.002). HHD scores and PAM were moderately correlated with the non-normalized Post-S condition (r= 0.44, p= 0.70) and strongly correlated with the non-normalized Pre-S condition (r= 0.62, p< 0.01). HHD scores of plantar flexor muscles give very limited information about the PF performance during walking in healthy individuals. Simple normalization did not improve the relations. Clinically measured isometric muscle strength and muscle weakness have only moderate strengths for establishing a treatment protocol and for predicting performance during walking in neurologically intact individuals.

Physiological and Biomechanical Responses to an Acute Bout of High Kicking in Dancers.

Rice, PE, Gurchiek, RD, and McBride, JM. Physiological and biomechanical responses to an acute bout of high kicking in dancers. J Strength Cond Res 32(10): 2954-2961, 2018-High-kick precision competitive dance involves the integration of kicking inline, jumping, and turning during a 3-minute routine and causes a disturbance to both aerobic and anaerobic systems. However, no known study has quantified the effect of a hick-kick-specific protocol on blood lactate (BL), heart rate (HR), and countermovement jump (CMJ) performance. A group of adolescent high-kick dancers (n = 20; age = 15.0 ± 1.8 years; height = 161.5 ± 8.2 cm; body mass = 56.3 ± 11.0 kg; and dance team/weight lifting experience = 2.1 ± 0.9 years) participated in this investigation. Participants' BL was collected, and 3 CMJ trials were performed before (PRE) and after (POST) completing the high-kick protocol. The high-kick protocol consisted of intermittent running and kicking in place for a total of 1:45 at a tempo of 160 b·min, while average and peak HR (HRavg; HRpeak) were recorded. Jump height (JH), maximal trunk flexion (MTF), take-off angle (TOA), and relative peak power (PP) were determined from PRE and POST CMJ trials. During kicking, HRavg and HRpeak (n = 13) were 172.4 ± 15.7 b·min and 207.0 ± 23.0 b·min, respectively. Dancers' (n = 20) BL significantly (p ≤ 0.05) increased from 1.5 ± 0.5 to 8.6 ± 1.5 mmol·L, and JH and PP significantly decreased from 0.42 ± 0.08 to 0.36 ± 0.04 m and 41.3 ± 5.5 to 38.5 ± 4.0 W·kg, respectively, from PRE to POST. No significant changes occurred in MTF and TOA measurements from PRE to POST. The demands introduced during a high-kick-specific protocol can therefore be recognized as a metabolic and mechanical stimulus for fatigue; however, esthetics seem to be unaffected. Such findings may indicate that this modality of dance necessitates supplemental strength and conditioning training similar to other sports to sustain the loads of high-kick dance.

Results of tenorrhaphy with early rehabilitation for acute tear of Achilles tendon.

For the treatment of acute Achilles tendon rupture, early rehabilitation after surgical repair is believed to be a useful method. The purpose of this study was to evaluate the outcome of open tenorrhaphy followed by early rehabilitation. A total of 112 patients who underwent open repair and early rehabilitation for acute Achilles tendon rupture from January 2003 to March 2015 were retrospectively reviewed. These 112 patients (80 men, 32 women) had an average age of 43.1 years (22-62 years), and the mean follow-up period was 91.8 months (12-171 months). A short leg cast was applied postoperatively for an average of 16.5 days (12-20 days). The mean duration of bracing was 6.9 weeks (6-8 weeks). Each patient was assessed based on range of motion, single heel raising test, calf circumference compared to the contralateral limb, ability to return to previous activity, the Arner-Lindholm scale, and the American orthopaedic foot and ankle society (AOFAS) hind foot scale. Isokinetic plantar flexion power was also checked. All patients were fully satisfied (AOFAS ≥ 90) with the treatment results, and 96 patients were able to return to their previous athletic activities. As assessed by the Arner-Lindholm scale, 103 cases were rated as excellent and the other 9 cases were rated as good. At the 1-year follow-up period, single heel raise and hopping was possible in every patient. Compared to the contralateral side, 10 subjects (8.9%) had minor limitation of dorsiflexion motion, and an average of 1.6 cm calf circumference difference without functional disabilities. There were no major complications such as re-rupture, nerve injury, or infection. For acute Achilles tendon ruptures, open surgical repair with optimal length restoration, followed by earlier rehabilitation results in good functional outcomes and a successful return to pre-injury levels of physical activity without major complications. Level IV.

Hip muscle power recovery after hip replacement using anterior-based muscle-sparing approach in elderly femoral neck fracture: a prospective study in 40 patients.

IntroductionThe early rehabilitation and mobilization after hip arthroplasty (HA) in elderly femoral neck fracture (FNF) patients significantly reduces the postoperative morbidity and mortality. The direct anterior approach (DAA) without the muscle detachment has been shown to improve the early postoperative functional outcomes in coxarthrosis patients. However, the application of DAA on elderly FNF and the most suitable surgical technique have rarely been investigated. This study aimed to report the short-term outcome after our anterior-based muscle-sparing approach (ABMS) in elderly FNF.Materials and methodsA prospective study, in 40 elderly unilateral FNF patients who underwent HA with ABMS, was conducted. The primary outcomes were hip flexion and abduction power at each follow-up period. The contralateral muscle power, measured at 3 and 6 months, was used as the control value. The perioperative data and complications were recorded.ResultsThirty-two patients underwent bipolar hemiarthroplasty (BHA), while eight other patients received total hip arthroplasty (THA). The hip abduction power returned to control value at 6 weeks (99.0%±6.1%; 95% CI: 86.1–111.8). The hip flexion power returned to control at 3 months (108.5%±5.6%, 95% CI: 96.8–120.2). No iatrogenic nerve injury was found. The intraoperative femoral fracture (IFF) was found in 7 patients (17.5%), and was significantly related to the early period of learning skill (first 11 cases; p<0.01). BHA had nonsignificant higher IFF than THA (8 vs. 0; p=0.31).ConclusionAfter ABMS, the hip muscle could recover to the baseline value within 3 months without iatrogenic nerve injury. The ABMS-related complication, which was IFF, could be significantly improved with the learning skill. The adequate posterior soft tissue release and gentle manipulation of the hip joint might play important roles for IFF prevention. BHA might relate to higher risk of IFF because of difficult reduction from large femoral head diameter.

Increased fatigue of the biceps after tenotomy of the long head of biceps tendon

The aim of this study is to evaluate the biomechanical parameters of biceps fatigue (time to claudication during elbow flexion) and strength between the shoulder where the tenotomy has been performed and the healthy arm. The hypothesis of this study was that measuring biceps fatigue may be more useful for determining functionality after tenotomy. 52 patients from 2 hospitals were selected to undergo biomechanical tests of healthy and pathological arms, before and 12 months after surgery. The test consisted of (1) isometric measurement of maximal voluntary contraction (MVC) in elbow flexion and forearm supination (MVS) at baseline conditions. (2) Biceps fatigue test was performed by a submaximal contraction to 33% of MVC maintained at a time as well recorded to the time to claudication. (3) After claudication, measurements of the MVC and MVS were recorded. In addition, the Constant score, SSI functional scale, VAS scale and perceived symptoms were evaluated. Of the 52 patients included in the study, 26 met the selection criteria. Two patients were lost to follow-up. The mean age was 55 ± 5.6years. Popeye sign was observed in 58.3% of the cases. Two patients were not satisfied with the results. Preoperatively, MVC was 193.6 ± 55.2N, which significantly improved after tenotomy to 252.1 ± 61.2N, but this value was less than the healthy arms (280 ± 68N). The fatigue time decreased from 141.9 ± 69.7s preoperatively to 94.2 ± 29.9s after tenotomy. There was also an improvement in the strength of the arm after the fatigue test. No differences in supination force were found. The Constant, SSI and VAS rating scales improved significantly. Despite functional improvements of the long head of biceps tendon (LHBT) after tenotomy, this study demonstrates that the shoulder where the tenotomy has been performed will fatigue more quickly than it did preoperatively. Despite this, an improvement in the isometric contraction in flexion of the elbow with respect to the preoperative values. However, this improvement did not reach the flexion power of the contralateral healthy arm. No changes were observed in the supination force of the forearm. III.

Avulsion fracture of the lesser trochanter in adolescents

IntroductionAvulsion fractures of the lesser trochanter in adolescents are rare. They are a result of a sudden and forceful contraction of the iliopsoas muscle. Functional results in the medium term after non-operative treatment are unknown. Therefore we aimed to report these in the present study. Materials and methodsA retrospective two-center study was performed in a case series treated between 2011 and 2017. All adolescents with an acute avulsion fracture of the lesser trochanter were included. Age, gender, mechanism of injury, fracture side, amount of displacement, and therapy were analyzed. In the follow-up, the Harris Hip Score (HHS), the sports level, the power of flexion in the hip, and signs of an ischio-femoral impingement (IFI) were investigated. ResultsAn avulsion fracture of the lesser trochanter was diagnosed in 4 boys and 1 girl. The mean age of the patients was 13.8 years (range: 13–15 years). We observed 2 type II and 3 type III fractures. The patients received similar non-operative treatment. Follow-up was performed at a mean of 4.9 years (range: 3.5–6.2 years) after injury. All patients returned to competitive sports. The Harris Hip Score (HHS) was 100 out of 100 points. History and provocation test concerning an IFI were negative in all patients. ConclusionOur study shows excellent results with non-operative treatment in acute avulsion fractures of the lesser trochanter in a case series of five adolescents. All patients returned to competitive sports. In our opinion, acute avulsion fractures of the lesser trochanter should be treated non-operatively.

Correlation of compound muscle action potential generated by donor nerves with the recovery of elbow flexion in Oberlin transfer in brachial plexus injury.

Objective:To study the correlation of compound muscle action potential of donor nerves with the recovery of elbow flexion in Oberlin transfer in brachial plexus injury.Introduction:Distal nerve transfer using motor fascicle of ulnar or median nerve to restore elbow flexion is a part of reconstructive surgery after upper brachial plexus injury, first described by Oberlin et al. However, one of the most critical influences on functional outcome is number of functioning motor axons in donor fascicle which is reflected by its compound muscle action potential. We studied whether nerve transfers with donor nerves showing higher amplitudes will yield better reinnervation of muscle and therefore better function as estimated by clinical examination.Methods:We prospectively studied 30 cases of upper brachial plexus injury, of which were treated with Oberlin transfer using ulnar or median or both nerves. The prerequisites were no elbow flexion and hand and wrist flexors showing the power of more than Medical research Council MRC Grade 4. Donor nerves selected either ulnar or median having CMAP >4 mv in our electrophysiology laboratory during nerve conduction study. Patients were followed up for 1 year and assessed clinically for restoration of elbow flexion, weight tolerance.Results:A total of 30 patients of Oberlin transfer were evaluated for improvement power of biceps and elbow flexion. (MRC) grading was done at 1 year. Twenty-seven patients had a good result (MRC grade ≥3), i.e., 90% of patients. Based on the MRC grades, we categorised the patients into two groups as follows: Group A and Group B. Group A included patients with MRC Grade 4–5 and Group B included Grades 3–3.5. We tried to establish a correlation between CMAP and MRC scores by comparison of MRC grade patients for their pre CMAPs which revealed a statistically significant higher CMAPs between the groups. (Mann–Whitney U-test, P = 0.028). This indicates the association of higher pre-CMAPs with higher MRC grades.Conclusion:We conclude that higher the compound muscle action potential of donor nerves, better the recovery of elbow flexion in Oberlin transfer in brachial plexus injury.

Brachioradialis to flexor digitorum profundus tendon transfer to restore finger flexion

Introduction:The main deformity following an adult lower brachial plexus injury is the loss of finger flexion. Distal nerve transfers have been used to restore finger and thumb flexion followed by tendon transfers for intrinsic replacement for opening of the fingers. When patients present beyond 6 months, only tendon transfers are applicable. Since the brachioradialis (BR) is always spared in such injuries, it is the ideal muscle to provide finger flexion. Wrist extensor power may not be normal for the use of the radial wrist extensor to serve as donor. BR to FDP transfer provides reasonable flexion range and an acceptable hand function to permit activities of daily living, when associated with ancillary procedures like opponensplasty, PIPJ arthrodesis.Materials and Methods:Eleven patients underwent a BR to FDP tendon transfer between January 2013 and January 2017 of which eight patients came for follow-up.Results:Four of the eight patients got a functionally useful hand to carry out activities of daily living with hook grip, span grasp, key pinch, chuck grip and pulp pinch. These patients also underwent simultaneous or secondary ancillary procedures. Four of the patients need secondary procedures to further improve functionality of the hand inspite of having a flexion range.Conclusion:The BR is an effective donor in providing adequate range and power of finger flexion in lower plexus injuries.

No difference in flexion power despite iliopsoas fatty degeneration in healed hip fractures with large lesser trochanter displacement

ObjectiveTo evaluate iliopsoas atrophy and loss of function after displaced lesser trochanter fracture of the hip.DesignCohort study.SettingDistrict hospital.PatientsTwenty consecutive patients with pertrochanteric fracture and displacement of the lesser trochanter of > 20 mm.InterventionFracture fixation with either an intramedullary nail or a plate.Outcome measurementsClinical scores (Harris hip, WOMAC), hip flexion strength measurements, and magnetic resonance imaging findings.ResultsCompared with the contralateral non-operated side, the affected side showed no difference in hip flexion force in the supine upright neutral position and at 30° of flexion (205.4 N vs 221.7 N and 178.9 N vs. 192.1 N at 0° and 30° flexion, respectively). However, the affected side showed a significantly greater degree of fatty infiltration compared with the contralateral side (global fatty degeneration index 1.085 vs 0.784), predominantly within the psoas and iliacus muscles.ConclusionSevere displacement of the lesser trochanter (> 20 mm) in pertrochanteric fractures did not reduce hip flexion strength compared with the contralateral side. Displacement of the lesser trochanter in such cases can lead to fatty infiltration of the iliopsoas muscle unit. The amount of displacement of the lesser trochanter did not affect the degree of fatty infiltration.Level of evidenceII.

Comparison of isokinetic trunk flexion and extension torques and powers between athletes and nonathletes.

This study is aimed to perform and compare maximal concentric isokinetic trunk extension and flexion torques and powers between high-level athletes and a control population. In addition, the ratio of isokinetic trunk extension and flexion torques was measured, and compared between groups. Eighteen high-level male athletes and 15 male nonathletes without low back pain were recruited. Subjects performed isokinetic trunk extension and flexion at 60°/sec, 90°/sec, and 120°/sec through a maximal range of motion in a dynamometer. Trunk extension torque of athletes was significantly higher than in nonathletes at 60°/sec and 90°/sec but not at 120°/sec. Trunk extension power of athletes was significantly higher than the control group at 90°/sec and 120°/sec but not at 60°/sec. There was no difference between the athlete and nonathlete groups in respect of trunk flexion torque or power at any angular velocity. Consequently, the ratio of trunk flexion to extension strength was greater in nonathletes than in athletes. Trunk extension and flexion torques tended to decrease, and trunk extension and flexion powers tended to increase, with increasing angular velocity. High-level athletes seem to display preferentially greater trunk extension strength and power in comparison with trunk flexion strength, compared to nonathletes. This could be caused by the use of strength training exercises such as squats and deadlifts, or it may be associated with greater athletic performance.