Adductor Research Articles

Effects of space allowance on behaviour during lairage, stress physiology, skin lesion scores and meat quality of market pigs transported in an actively-ventilated vehicle in the winter

A total of 1,488 pigs were transported to slaughter using a mechanically-ventilated vehicle in the winter in Canada. On each of six journeys, a sub-sample of 78 pigs were randomly assigned to two space allowances (0.46 or 0.53 m2/pig), distributed across six compartments, in two positions (near-front and near-rear) and three deck levels (top, middle, and bottom). Compartment ambient conditions (e.g., T°C and RH%) were monitored during transport and pig behaviour was recorded during lairage. Blood lactate, hematocrit, creatine kinase (CK) concentrations and meat quality in the longissimus (LM), semimembranosus (SM), and adductor (AD) muscles were assessed on a total of 108 pigs. Pigs transported at 0.53 m2/pig had greater blood hematocrit levels (P = 0.05), but lower blood CK concentrations at slaughter (P = 0.01). The top deck was colder during all transport events (P < 0.001), and pigs transported in this location stood less in lairage compared to those transported on the bottom deck (P = 0.05). Pigs from the top deck showed lower L* values in the LM and SM muscle (P = 0.02 and P = 0.04, respectively). Overall, animal location had a greater impact than space allowance on animal welfare and meat quality of pigs.

Lower limb strength and training experience in elite and sub-elite female footballers

BACKGROUND: Strength differences between performance levels remain unclear in female football. Furthermore, the relationship between fulltime training and strength has been unexplored despite increased professionalisation in the sport. OBJECTIVE: The aims of this research were to examine knee flexor/extensor and hip adductor/abductor strength differences between elite and sub-elite female footballers, and then determine the relationship of strength performance to age, years of football experience (FE), and years of fulltime training (FTT). METHODS: 15 elite and 15 sub-elite professional female footballers were tested. The main outcomes were concentric isokinetic knee flexor and extensor peak moment at 60, 180, and 300∘/s, and isometric hip adductor (ADD) and abductor (ABD) force. RESULTS: The elite team had higher absolute (300∘/s: 47.13–49.33 Nm vs 37.33–38.93 Nm, p< 0.05) and normalised (300∘/s: 0.76–0.80 Nm/kg vs 0.59–0.62 Nm/kg, p< 0.05) knee flexor values, and higher normalised ADD (5.64–5.66 N/kg vs 4.98–5.05 N/kg, p< 0.05) and ABD force (5.80–6.00 N/kg vs 5.26–5.39 N/kg, p< 0.05), compared to the sub-elite team. Age, FE, and FTT were correlated to knee flexor values (r= 0.381–0.559, p< 0.05). Additionally, FTT was correlated with normalised ADD and ABD force (r= 0.362–0.546, p< 0.05). CONCLUSION: Sub-elite female footballers may require additional knee flexor and hip strengthening in order to make the step up to the elite level. Those who are younger or have low FTT may also be recommended additional lower limb strengthening ahead of joining a fulltime training environment.

EVALUATING DYNAMIC BALANCE AND ISOMETRIC HIP MUSCLE STRENGTHS OF HEALTHY ADOLESCENTS WITH DIFFERENT FOOT POSTURE ALTERATION

Hip abductor (ABD) and adductor (ADD) muscle imbalances lead to injuries in lumbo-pelvic hip complex, and these imbalances and other factors such as foot posture might affect dynamic balance. The present study aims to examine body mass index (BMI), dynamic balance and hip muscle strength values of adolescents with different foot posture alteration. Fifty-nine healthy adolescents (mean age 12±3 years, height 156±11.46 cm, weight 50.57±11.60 kg) voluntarily participated in the study. The participants were divided into two groups according to Foot Posture Index (FPI): (Neutral Foot Group (NFG), n=48 / Prone Foot Group (PFG), n=11). The participants’ single leg – both legs dynamic balance values were measured by using balance measurement device (TOGUtm), and their hip ABD and ADD isometric muscle strengths were measured through the load cell. The dynamic balance, BMI and muscle strength values of the groups were compared by using Independent Sample t-Test. A statistically significant difference was found between the groups according to right and left single leg dynamic balance values (p<0.05). The study revealed that one of the most significant factors affecting dynamic balance in adolescents is foot posture. It is believed that using insoles suitable for the foot posture might be helpful in increasing the efficiency of dynamic movements carried out on a single leg and it is essential to suggest some exercises to correct foot postures when necessary.

Physical fitness and throwing speed in U13 versus U15 male handball players

BackgroundThe aim of this study was to analyze the shoulder functional profile (rotation range of motion [ROM] and strength), upper and lower body performance, and throwing speed of U13 versus U15 male handball players, and to establish the relationship between these measures of physical fitness and throwing speed.MethodsOne-hundred and nineteen young male handball players (under (U)-13 (U13) [n = 85]) and U15 [n = 34]) volunteered to participate in this study. The participating athletes had a mean background of sytematic handball training of 5.5 ± 2.8 years and they exercised on average 540 ± 10.1 min per week including sport-specific team handball training and strength and conditioning programs. Players were tested for passive shoulder range-of-motion (ROM) for both internal (IR) and external rotation (ER) and isometric strength (i.e., IR and ER) of the dominant/non-dominant shoulders, overhead medicine ball throw (OMB), hip isometric abductor (ABD) and adductor (ADD) strength, hip ROM, jumps (countermovement jump [CMJ] and triple leg-hop [3H] for distance), linear sprint test, modified 505 change-of-direction (COD) test and handball throwing speed (7 m [HT7] and 9 m [HT9]).ResultsU15 players outperformed U13 in upper (i.e., HT7 and HT9 speed, OMB, absolute IR and ER strength of the dominant and non-dominant sides; Cohen’s d: 0.76–2.13) and lower body (i.e., CMJ, 3H, 20-m sprint and COD, hip ABD and ADD; d: 0.70–2.33) performance measures. Regarding shoulder ROM outcomes, a lower IR ROM was found of the dominant side in the U15 group compared to the U13 and a higher ER ROM on both sides in U15 (d: 0.76–1.04). It seems that primarily anthropometric characteristics (i.e., body height, body mass) and upper body strength/power (OMB distance) are the most important factors that explain the throw speed variance in male handball players, particularly in U13.ConclusionsFindings from this study imply that regular performance monitoring is important for performance development and for minimizing injury risk of the shoulder in both age categories of young male handball players. Besides measures of physical fitness, anthropometric data should be recorded because handball throwing performance is related to these measures.

Use of two novel trailer types for transportation of pigs to slaughter. I. Effects on trailer microclimate, pig behaviour, physiological response, and meat quality under Canadian summer conditions

A total of 3366 pigs were transported to slaughter in summer (six replicates/trailer type; July-August in southwestern Ontario) using three trailers: a modified triple-deck pot-belly (MPB), an advanced flat-deck (AFD), and a standard pot-belly (SPB). Within trailers, ambient conditions, temperature (T °C), relative humidity (RH%), and temperature-humidity-index (THI), were monitored in three compartments (bottom front, BF, middle deck, MM, and top rear, TR). A total of 162 pigs were selected for the analysis of hematocrit, lactate, and creatine kinase (CK) levels in exsanguination blood and for the evaluation of pork quality as assessed in the longissimus (LM), semimembranosus (SM), and adductor (AD) muscles. The AFD and MPB trailers presented lower ( P < 0.01) T°C and THI compared to the SPB during transit. In the SPB trailer, pigs transported in the MM compartment showed higher ( P < 0.01) blood CK concentrations than those transported in the BF compartment and lower pHu values in the SM and AD muscles ( P = 0.02 and P = 0.04, respectively) than those transported in the TR compartment. Although the AFD trailer design provided a better microclimate for pigs, the improvements in the design of the novel trailers only slightly reduced stress in pigs during summer transits.

Use of two novel trailer types for transportation of pigs to slaughter. II. Effects on trailer microclimate, pig behaviour, physiological response, and meat quality under Canadian winter conditions

In total, 3654 market pigs were transported to slaughter in winter (six replicates/treatment; January–February in southwestern Ontario) using three trailers: a modified triple-deck pot-belly (MPB), an advanced flat-deck (AFD) trailer, and a standard pot-belly (SPB). Within trailers, ambient conditions, temperature (T °C), relative humidity (RH%), and temperature humidity index (THI) were monitored in three compartments (bottom front (BF), middle middle deck (MM), and top rear (TR)). In total, 162 pigs were selected for the analysis of hematocrit, lactate, and creatine kinase (CK) levels in exsanguination blood and for the evaluation of pork quality as assessed in the longissimus (LM), semimembranosus (SM), and adductor (AD) muscles. The SPB trailer overall was approximately 2.5 °C warmer ( P = 0.01) compared to the MPB and AFD trailers while stationary at the farm. No differences ( P > 0.10) in blood variables were found between trailers. The pHu value of the SM muscle was greater ( P = 0.05) for pigs transported in the SPB trailer than in the AFD and MPB trailers. Given the few substantial effects of trailer models on animal welfare and meat quality, these three trailer models can be used indifferently for short-distance transportation in winter conditions in Canada.

Impact of hip abductor and adductor strength on dynamic balance and ankle biomechanics in young elite female basketball players

This study aimed to evaluate, in an isolated and relative manner, hip abductor (ABD) and adductor (AD) strength and to study the extent to which these factors are related to balance and ankle dorsiflexion mobility in young elite female basketball players. Sixty trainee-level elite female basketball players (13–18 years old), who voluntarily agreed to participate in the study, were divided into three subgroups based on competition age divisions (U14, U16, U18). Isometric hip ABD and AD strength in each leg was evaluated using the ForceFrame Strength Testing System, also calculating the strength ratio and imbalance between legs. Y Balance Test (YBT) and ankle dorsiflexion mobility were also assessed. ANOVA was used for between-group differences analysis. Likewise, the impact of hip strength on balance and ankle mobility was analyzed using Pearson's correlation coefficient. A linear regression model for dependent variables was created with all variables that exhibited significant correlations. A between-group comparison analysis for the three competition age subgroups (U14, U16, U18) revealed non-significant differences (p > 0.005) for the hip strength variables except for hip ABD strength. The correlation study showed low-moderate effect sizes for hip ABD (in both the contralateral and homolateral limb) and AD strength (only the homolateral limb) with YBT and ankle dorsiflexion. However, when performing a regression model, only right hip ABD significantly predicted right limb YBT scores (β = 0.592, p = 0.048). The present study indicated that, although both hip ABD and AD strength correlate with balance and ankle mobility with low-moderate effect sizes, only hip ABD strength was found to significantly predict YBT scores. Therefore, the potential role of hip ABD strength in particular, but also hip AD strength, for monitoring and enhancing balance and ankle mobility outcomes, should be taken into consideration when designing and implementing preventive strategies for lower-limb injuries.

Field based lower limb strength tests provide insight into sprint and change of direction ability in academy footballers

Conducting field-based strength assessments is embedded within football academy development processes. Yet, there is a limited understanding of how hip and groin strength assessments relate to vital game-based tasks such as sprinting and change of direction (COD) performance. Our aim was to explore field-based strength assessments and their relationships with both sprint and COD performance in male academy footballers. Participants (n=146; age 14.2±2.2years; stature 166.3±15.4cm; body mass 55.6±15.6kg) performed maximal countermovement jump (CMJ), Nordic hamstring strength (NHS), isometric hip adductor (ADD)/abductor (ABD), 5m, 10m, 20m sprints, and modified 505 agility test. All strength measures were allometrically scaled to account for body weight. Between-limb differences were reported as imbalance scores. Principal component analysis reduced sprint and COD variables to a single "running ability" component score. Scaled strength and imbalance, when controlled for age, were associated with "running ability" (adjusted R2 =0.78, p<0.001). Significant effects on "running ability" included the following: age, CMJ impulse, NHS, and hip-ADD. When the sprint and COD variables were explored independently, age and CMJ-impulse were featured in all sprint and COD models. For 10m and 20m sprint distances, hip-ADD emerged as a significant effect. Mean 505 performance was explained by age, CMJ-impulse, hip-ADD, but also with the addition of NHS. Our findings suggest that insight into the underpinning strength qualities of "running ability" of academy footballers can be obtained from a suite of field-based tests.

The Acute Effect of Match-Play on Hip Isometric Strength and Flexibility in Female Field Hockey Players

The aim of this study was to determine the acute effect of simulated field hockey match-play on isometric knee flexion, adductor (ADD) and abductor (ABD) strength, adductor/abductor (ADD/ABD) strength ratio, countermovement jump height (CMJ), hip flexion and ankle dorsiflexion range of motion (ROM). Thirty competitive female field hockey players (23.0 ± 3.9 years old) participated in the study. Apart from the afore-mentioned variables, external (through GPS) and internal load (through RPE) were measured before (pre-match) and immediately after simulated hockey match-play (post-match) in both limbs. Isometric knee flexion strength (+7.0%, p = 0.047) and hip flexion ROM (+4.4%, p = 0.022) were higher post-match in the non-dominant limb, while CMJ values reduced (−11.33%, p = 0.008) when comparing from pre-match data. In addition, no differences were observed for isometric hip ADD, ABD, ADD/ABD strength ratio, passive hip flexion ROM and ankle dorsiflexion ROM test. A simulated field-hockey match produces an increment in hip isometric strength and hip flexion ROM values in the non-dominant limb and a decrease in jump height capacity. As a result, CMJ assessment should be considered post-match in order to identify players who would require further rest before returning to training.

The acute effect of match-play on hip range of motion and isometric strength in elite tennis players.

BackgroundGroin injuries are some of the most common injuries tennis players suffer. Several factors (e.g., post-match decrease in hip adductor (ADD) strength) have been proposed as possible mechanisms for increasing the incidence of this type of injury. However, the risk factors of developing groin injuries after a tennis match have not yet been delineated.ObjectiveThe aim of this study was to determine the effect of tennis match-play on isometric ADD and abductor (ABD) strength and passive hip range of motion (ROM).MethodsTwenty-six male tennis players (20.30 ± 4.98 years) took part in this study. Participants completed an evaluation of strength and flexibility hip measurements before and after a simulated tennis match. Dominant and non-dominant passive hip ROM, ADD and ABD isometric strength, and the ADD/ABD strength ratio were measured before and immediately post-match. A global positioning system (GPS) and a session rating of perceived exertion (RPE) were used to assess the locomotive demands and internal match load.ResultsIsometric dominant ADD strength (17.8%, p ≤ 0.01) and ADD/ABD strength ratio (11.6%, p = 0.04) were lower post-match compared to the pre-match values. No between-limbs differences were observed for isometric ADD strength, ABD strength, and passive hip ROM tests. RPE showed an expected increase between pre- vs. post-match (pre- vs. post-warming-up, 3.42 ± 2.08 vs. 5.62 ± 2.29, p < 0.01). In addition, a significant relationship between ADD strength and the volume of tennis practice per week was found, stablishing that tennis players with lower volume of training per week suffered a reduction in ADD strength in their dominant limb after match-play (r = 0.420, p = 0.04).ConclusionThe assessment of ADD strength and the ADD/ABD strength ratio in the dominant limb may be considered a post-match tool that can be used to identify players who require rest and additional recovery strategies before competing again.

Palatability of beef chuck, loin, and round muscles from three USDA quality grades.

The objective of this study was to determine the palatability of various beef cuts from 3 USDA quality grades. Five different beef subprimals from USDA Prime, Choice, and Select (n = 10/quality grade) carcasses were utilized for the study, including: strip loins, inside rounds, bottom rounds, shoulder clods, and chuck rolls. Subprimals were fabricated into 9 retail cuts, which contained the following beef muscles: longissimus lumborum (LL); longissimus thoracis, complexus, and spinalis dorsi (LCS); infraspinatus (IF); serratus ventralis (SV); triceps brachii (TB); teres major (TM); adductor (AD); semimembranosus (SM); and biceps femoris (BF). The pH and percentage of fat, moisture, protein, and collagen was determined for each muscle on a raw basis. Additionally, cooked steak measurements included Warner-Bratzler shear force (WBSF) and slice shear force (SSF). Consumer and trained sensory panelists evaluated palatability traits of each cut and quality grade combination. A quality grade × muscle interaction was determined for trained panelists assessment of overall tenderness (P = 0.03), SSF (P = 0.02), proximate composition (P < 0.01), and pH (P < 0.01). In all objective and subjective measurements of tenderness, the LCS was the most tender (P < 0.05), while cuts from the round (BF, AD, and SM) were among the toughest and least juicy (P < 0.05). Conversely, consumers and trained sensory panelists identified the LCS, IF, and SV to be juicier (P < 0.05) than all others. The TB, TM, and LL were perceived by consumers most often as being everyday quality. The LCS was found by consumers to be the most acceptable (P < 0.05) across all attributes, with the SM being the least (P < 0.05) acceptable muscle. For each muscle, fat percentage was the greatest (P < 0.05) in Prime cuts. Slice shear force determined Prime IF, LL, and SV to be more tender (P < 0.05) than Choice and Select. No SSF differences (P > 0.05) were found among quality grades for the AD, BF, and SM. The WBSF values decreased (P < 0.05) across all muscles, as quality grade increased (Prime < Choice < Select). The results of this study indicate that muscles from the chuck may be utilized to provide consumers with a positive eating experience. Meanwhile, muscles from the round are likely to provide consumers with a lower quality eating experience.

Characteristics of selected pork muscles 45 min and 24 h post mortem

The muscles of the pork topside – musculus adductor (AD) and m. semimembranosus (SM), and of the silverside – m. biceps femoris (BF) and m. semitendinosus (ST) were analysed and their properties compared with the m. longissimus thoracis (LT) and m. supraspinatus (SS) muscles. Colour (CIE L*a*b*), D/L-lactic acid content, and pH values were measured 45 min and 24 h post mortem. The basic chemical composition of muscles was analysed 24 h after slaughtering. A significant correlation (r = -0.61, P &lt; 0.001) was found between the pH values and the level of lactic acid 45 min post mortem, though not 24 h after slaughter (r = -0.25, P &gt; 0.05). The results confirmed that a direct comparison cannot be made between the fall in pH values in meat and the increase in the level of lactic acid. The lightness L* 24 h post mortem was higher (P &lt; 0.05) in AD, BF, ST and LT muscles than those in samples measured 45 min after slaughter. The toughest muscle was biceps femoris, with a mean value of shear force of 90.5 N. The differences in shear force between the individual analysed muscles were significant (P &lt; 0.05). There were significant differences in the intramuscular fat content between the topside and silverside muscles (P &lt; 0.05). The results of the present study are of value to meat producers who might intend to substitute these parts of the leg with one another during the production, particularly in the case of whole-muscle meat products.

Three-dimensional comparison of intramuscular fat content between young and old adults

BackgroundFat infiltration within skeletal muscle is known as intramuscular fat (IMF), which increases with aging. Studies have assessed IMF content, using the mid-thigh as a representative location. However, three-dimensional IMF distribution is not well understood. The aim of this study was to compare the IMF content in young and old adults by assessing its distribution along the length of the thigh.MethodsConsecutive transaxial images of the right thighs in 15 young (age, 21.0 ± 0.4) and 15 old (age, 70.7 ± 3.8) were obtained by magnetic resonance imaging. We measured IMF cross-sectional area (CSA), skeletal muscle CSA and calculated volume- and CSA-based IMF content for the quadriceps femoris (QF), hamstring (HM) and adductor (AD). CSA-based calculations were performed at every 10% of femur length (Lf), with 0% Lf and 100% Lf indicating the proximal and distal ends of femur.ResultsIMF CSAs along the length of the thigh were similar in both age groups. In contrast, skeletal muscle CSAs in all three muscle groups were significantly lower in old adults than in young adults (variation: −15.2 to −1.6 cm2, P < 0.05). Thus, in volume-based measurements, the older adults had higher IMF contents than the younger adults (9.5% to 14.3% vs. 4.8% to 8.6%, respectively; P < 0.05). However, such age-dependent differences were not observed at the mid-thigh in the QF and AD.ConclusionThe results demonstrated an age-related increase in IMF content—confirmed in areas of the thigh—primarily based on finding lower amounts of skeletal muscle mass in CSAs in the older adults.

Determination of Objective Analysis of Juiciness among Multiple Beef Muscles and Quality Grades

ObjectivesThe purpose of this study was to use a developed objective juiciness analyses including corresponding tenderness measurements to determine the juiciness among multiple beef muscles of various quality grades.Materials and MethodsTreatments were obtained from 5 different beef sub-primals: Strip loins (IMPS #180), inside rounds (IMPS #169), bottom rounds (IMPS #171B), shoulder clods (IMPS #114), and chuck rolls (IMPS #116). Sub-primals were also represented by 3 different USDA quality grades: Prime, Low Choice and Select; (n = 10/quality grade). All sub-primals were vacuum packaged, aged for 21dthen fabricated into 2.5 cm thick steaks from respective cuts: Adductor (AD), Biceps femoris (BF), Chuck Eye (CE), Infraspinatus (IF), Semimembranosus (SM), Serratus ventralis (SV), Longissimus lumborum (LD), and Triceps brachii (TB). The steaks were frozen (–20°C) until subsequent analyses. Several objective measures of juiciness and tenderness were evaluated on raw and cooked samples. Analysis techniques measured on raw samples included: pH and percentage fat, moisture, protein and collagen. Cooked techniques evaluated included: Warner-Bratzler shear force (WBSF), slice shear force (SSF), cook loss, and pressed juice percentage (PJP). For cooked analysis, each steak was cooked on a clam-shell grill to a medium degree of doneness (71°C), and the fiber orientation (45 or 90°) was determined before sampling. Analysis of PJP was evaluated using a compression-based juiciness method. Following SSF, a 1cm thick PJP slice was removed parallel with predetermined muscle fiber orientation (45 or 90°) and compressed on filter paper at 8 g for 30s. Data were analyzed using the GLIMMIX procedure of SAS (SAS Inst. Inc., Cary, NC; ɑ = 0.05). Subprimal was experimental unit, and muscle, quality grade, muscle × quality grade were used as fixed effects. Carcass was used as a random effect.ResultsA muscle × quality grade interaction (P < 0.05) was detected for each chemical proximate measurement, as well as pH. Fat percentage for SV was greater (P < 0.05) than all other cuts in all quality grades, but similar (P > 0.05) to IF in the Select grade. Within Prime and Low Choice, moisture was greatest (P < 0.05) for TB and similar (P > 0.05) to AD. The pH was lowest (P < 0.05) for AD in all grades. The IF was highest (P < 0.05) in Choice and Select, but similar (P > 0.05) to Choice TB, LD and Select TB. A muscle × grade interaction (P < 0.05) was found for SSF. The BF across all quality grades was the toughest (P < 0.05). The SV was the most tender (P < 0.05) in Prime, however few differences were found in all other quality grades between muscles of AD, IF, LD, and SV. Quality grade and muscle affected (P < 0.05) WBSF and PJP. As quality grade increased, WBSF values decreased (P < 0.05). The SV and CE were more tender (P < 0.05) than AD, TB, and IF. The PJP was less (P < 0.05) for Prime and Choice than Select, while TB and SM were greater (P < 0.05) than IF and AD for the same trait.ConclusionObjective juiciness and tenderness measures among different beef cuts and quality grades cooked to the same degree of doneness indicated that there is a difference in the amount of juice that is released from various beef muscles.

The Effect of PSE and Non-PSE Adductor and Semimembranosus Pig Muscles on the Occurrence of Destructured Zones in Cooked Hams

The aim of this study was to analyse pig muscles used in the production of cooked hams with a view to the occurrence of PSE-type defects and their potential effect on the frequency of destructured zones in finished products. One hundred and six samples of m. adductor (AD) and m. semimembranosus (SM) pig muscles were studied. The two kinds of muscle differed from each other in terms of their pH values and colour (L⁎: lightness, a⁎: redness, and b⁎: yellowness); these differences between the two categories were statistically significant (P&lt;0.001). The AD muscles were divided into meat with PSE (pale, soft, and exudative) defects and non-PSE meat by sensory examination. A total of 44.3% of AD muscles showed PSE defects. Lightness L⁎ fell within a range of 50.68–55.23 in non-PSE meat (AD) and was statistically significantly lower (P&lt;0.001) than in PSE meat (56.25–58.78). Drip loss (AD) was higher (P&lt;0.001) in PSE meat (4.83–6.27%) than in non-PSE meat (3.53–5.0%). Cooked hams prepared from pig muscles showed evident destructured zones when sliced, the number and overall area of which were not affected by the occurrence of PSE defects in the raw meat used.

Potential Risks And Distribution Pattern Of Intramuscular Fat In Obese Children

PURPOSE: The purpose of this study was to assess relationship between IMF and physiological and biochemical variables. METHODS: Thirty-seven obese boys and girls participated in this study (age, 10.4 ± 2.1 years; height, 146.2 ± 13.4 cm; weight, 56.1 ± 16.5 kg; percentage of overweight, 41.1 ± 16.8%). This study was conducted a part of treatment of the subjects and was approved by the institutional review board of local committees. Computed tomography (CT) images were taken at the mid-thigh and umbilicus levels. Using the CT images, IMF index of the quadriceps femoris (QF), hamstrings (HM) and adductor (AD) muscle groups based on mean grey scale level of the interested muscle groups and visceral fat cross-sectional area (CSA) were calculated. For the mid-thigh CT image, skeletal muscle CSA and subcutaneous fat was also calculated. Plasma triglyceride, FFA, HDL-cholesterol, total-cholesterol, AST, ALT, glucose and HbA1c were measured from fasting blood drop. RESULTS: IMF index of QF, HM and AD was significantly different in all comparisons: HM was the lowest (1066 ± 6), meaning largest IMF depot, and QF was the highest (1080 ± 3), meaning smallest IMF depot. Stepwise regression analysis revealed that QF CSA, visceral fat CSA, and triglyceride were extracted to predict IMF index in QF (R=0.707, P < 0.01). For IMF index in HM, visceral fat CSA, age, triglyceride, percentage of overweight, and sex were extracted (R=0.806, P < 0.01). Interestingly, percentage of overweight was the only extracted variable to predict IMF index in AD (R=0.529, P < 0.01). CONCLUSIONS: These results suggest that muscle-specific IMF deposition pattern was observed in obese children and that intramuscular fat in each muscle group may have physiological and biochemical specific roles.

Effect of Ageing Time on Microstructure, Rate of Desmin Degradation and Meat Quality of Pig Longissimus Lumborum and Adductor Muscles.

This study evaluated the effect of ageing time (45 min, 24 h, 96 h and 168 h) on desmin degradation pattern, meat quality and muscle fibre traits in longissimus lumborum (LL) and adductor (AD) muscles of 28 Polish Landrace fatteners slaughtered at 105 kg body weight. The results indicate that the rate of desmin degradation depends on pH and type of muscle, and thus on muscle fibre composition. In AD muscle, characterized by significantly higher pH45, pH24 and shear force values, lower drip loss, significantly higher percentage of type I and IIA oxidative fibres, and lower percentage of type IIB glycolytic fibres, desmin degradation is slower than in LL muscle. The rate of desmin degradation is also associated with its localization in muscle fibre. Regardless of muscle type, in all muscle fibres desmin was degraded more rapidly within, rather than at the periphery of the fibres. Additionally, levels of intact desmin and drip loss during postmortem meat storage contribute significantly to a reduction in the diameter of three fibre types analysed in AD and LL muscles 24 h postmortem and of type IIB fibres in AD muscle 96 hpostmortem. Furthermore, the decrease in the level of intact desmin is paralleled by a cumulative increase in drip loss and a decrease in shear force at 45 min, 24 h and 96 h postmortem.

Skeletal muscle size is a major predictor of intramuscular fat content regardless of age.

Skeletal muscles of older individuals have a larger amount of intramuscular adipose tissue (IntraMAT) than those of younger individuals. It is not understood how aging affects the IntraMAT content of individual muscles of the thigh. We assessed the relationship between IntraMAT content and skeletal muscle cross-sectional area (CSA), subcutaneous adipose tissue CSA, biochemical blood profiles, and physical activity. Fifteen older (70.7 ± 3.8 years) and 15 younger (20.9 ± 0.3 years) men and women participated in this study. Magnetic resonance imaging of the right thigh was taken to measure IntraMAT content and skeletal muscle CSA for the quadriceps femoris (QF), hamstrings (HM), adductor (AD) muscle groups and subcutaneous adipose tissue CSA of the thigh. Fasting blood samples were collected to measure plasma lipids, adiponectin, and HbA1c levels. IntraMAT content in QF, HM, and AD for the Older group was significantly higher than in the Younger group. However, skeletal muscle CSA normalized by body weight (skeletal muscle CSA/bw) in the QF (P < 0.001) and total thigh (P < 0.01) were significantly lower in the Older group compared with the Younger group.There were no significant differences in HM and AD. Stepwise regression analysis with IntraMAT content as a dependent variable revealed that skeletal muscle CSA/bw of the thigh was the only predictive variable for IntraMAT content in Older and Younger groups. These results suggest that skeletal muscle size could be a major determinant of IntraMAT content regardless of age.

Hand-held lactate analyzer as a tool for the real-time measurement of physical fatigue before slaughter and pork quality prediction

The objectives of this study were to assess the relationship between blood lactate variation measured at the plant, and pork quality variation on a large sample size and under commercial preslaughter handling conditions. A total of 600 pigs were randomly chosen on arrival at a commercial slaughter plant and blood samples taken from the ear vein at unloading (UN), after lairage (LA), in the restrainer (RE; before stunning) and at exsanguination (EX) were analysed for lactate content using a Lactate Scout Analyzer (LSA). In order to have a large range of measures, pigs were distributed into two groups; one kept in lairage overnight (G1) and the other for 2 to 3 h (G2) before slaughter. Meat quality was assessed in the Longissimus thoracis (LT), Semimembranosus (SM) and Adductor (AD) muscles by measuring the pH 30 min postmortem (pH1) and at 24 h postmortem (pHu), the colour and the drip loss. Blood lactate levels did not differ between G1 and G2 (P>0.05). A reduced muscle lactate and glucose contents (P=0.02 and P=0.004, respectively) resulting in a lower (P<0.001) glycolytic potential (GP) was observed in the LT muscle of G1 pigs when compared with G2 loins. In the LT muscle of G1 pigs, the lower GP resulted in an increased pHu (r=−0.67; P<0.001), decreased drip loss (r=0.57; P<0.001) and darker colour (r=0.50; P<0.001) compared with G2. In both G1 and G2 pigs, the lower GP was correlated to higher pHu value in the SM and AD muscles (r=−0.73; P<0.001). The greatest correlation was observed in G2 between blood lactate levels at LA and pHu value of the SM and AD muscles (r=0.46 and r=0.44, respectively; P<0.001 for both muscles). The second greatest correlation was found between blood lactate levels at EX and pH1 value in the SM muscle in both groups (r=−0.37 and r=−0.41, respectively; P<0.001 for both groups). Based on the results of this study, it appears that blood lactate levels, as measured by the LSA, reliably reflect the physiological response of pigs to perimortem stress and may help explain the variation in pork quality.

Effect of early postmortem enhancement of calcium lactate/phosphate on quality attributes of beef round muscles under different packaging systems

The objective was to determine the influence of calcium lactate/phosphate enhancement on quality of beef round cuts in high-oxygen modified atmosphere (HiOx-MAP; 80% O2/20% CO2). Mm. semimembranosus (SM), semitendinosus (ST), and adductor (AD) were divided and assigned to water-injected control (CON), 3mM phosphate (STP), or 200mM calcium lactate/3mM phosphate (CAL/STP) treatments at 24h postmortem. Steaks (n=10) were vacuum packaged (VAC) and stored for 9days, then displayed for 7days in VAC or HiOx-MAP. Lipid oxidation, pH, surface color, star probe, and sensory characteristics were evaluated. HiOx-MAP resulted in greater lipid oxidation, more discoloration, and decreased sensory quality of steaks (P<0.05) compared to VAC. However, CAL/STP enhancement significantly reduced lipid oxidation of all steaks, decreased ST and SM star probe values, and improved tenderness of HiOx-MAP packaged AD and SM (P<0.05). Results suggest that CAL/STP enhancement has beneficial effects on lipid stability and sensory attributes of beef round cuts under HiOx-MAP.