Peak Patellofemoral Force Research Articles

IMMEDIATE EFFECTS OF SEMI-CUSTOM INSOLES AND STRUCTURED KNEE SLEEVES ON LOWER EXTREMITY KINETICS AND KINEMATICS IN RECREATIONAL MALE ATHLETES WITH PATELLOFEMORAL PAIN

The aim of this experiment was to provide insight into the immediate influence of both semi-custom insoles and knee sleeves in recreational male runners/athletes suffering from patellofemoral pain and also to explore the association between the extent of patellofemoral pain and psychological wellbeing. Experiment 1 examined 17 male recreational runners with patellofemoral pain, in semi-custom insole and no-insole conditions. Experiment 2 examined 13 male recreational athletes with patellofemoral pain, undertaking run, [Formula: see text] cut and single-leg hop movements in knee sleeve and no-sleeve conditions. In both experiments, motion capture and ground reaction forces were collected, allowing kinetics and three-dimensional kinematics to be calculated alongside patellofemoral joint loading quantified using musculoskeletal modeling. In both experiments, patellofemoral pain symptoms were examined using the KOOS patellofemoral pain subscale and psychological wellbeing using the COOP-WONCA questionnaire. The findings from both experiments showed that pain symptoms significantly predicted psychological wellbeing ([Formula: see text] in experiment 1 and [Formula: see text] in experiment 2). Experiment 1 showed that orthoses significantly reduced tibial internal rotation range of motion (no-[Formula: see text] and [Formula: see text]) whilst also increasing the peak knee adduction moment (no-[Formula: see text][Formula: see text]N[Formula: see text]m/kg and [Formula: see text][Formula: see text]N[Formula: see text]m/kg). The findings from experiment 2 revealed that the knee sleeve reduced the peak patellofemoral force (no-[Formula: see text][Formula: see text]BW and [Formula: see text][Formula: see text]BW) in the run movement and the patellofemoral load rate in the cut movement (no-[Formula: see text][Formula: see text]BW/s and [Formula: see text][Formula: see text]BW/s). Overall, the findings confirm that pain symptoms are predictive of psychological wellbeing in recreational male athletes with patellofemoral pain. Furthermore, the findings suggest that both insoles and knee sleeves may provide immediate biomechanical benefits in recreationally active individuals with patellofemoral pain, although when wearing insoles this may be at the expense of an increased knee adduction moment during running.

Mechanical effects of medial and lateral wedged orthoses during running

ObjectiveThe aim of the current investigation was to examine the effects of orthoses with 5° medial and lateral wedges on knee joint kinetics during the stance phase of running. DesignRepeated measures. SettingLaboratory. ParticipantsTwelve recreational runners. Outcome measurementsTwelve male participants ran over a force platform at 4.0 m/s in three different conditions (medial orthotic, lateral orthotic and no-orthotic). Lower limb kinematics were collected using an 8-camera motion capture system allowing knee kinetics to be quantified using a musculoskeletal modelling approach. Differences in knee joint kinetics between orthotic conditions were examined using one-way repeated measures ANOVA. ResultsThe results showed that peak patellofemoral force was significantly increased in the medial (31.81 N/kg) and lateral (31.29 N/kg) wedged orthoses, in comparison to the no-orthotic (29.61 N/kg) condition. In addition, the peak knee adduction moment was significantly increased in the medial (1.10 Nm/kg) orthoses, in comparison to the lateral (0.87 Nm/kg) condition. ConclusionsThe results from this study indicate that lateral orthoses may be effective in attenuating runners risk from medial tibiofemoral compartment OA, but that wedged orthoses may enhance their risk from patellofemoral pain.

The ideal posture in power position related to the spinal alignment

The aim of the current investigation was to examine the effects of orthoses with 5° medial and lateral wedges on knee joint kinetics during the stance phase of running.Repeated measures.Laboratory.Twelve recreational runners.Twelve male participants ran over a force platform at 4.0 m/s in three different conditions (medial orthotic, lateral orthotic and no-orthotic). Lower limb kinematics were collected using an 8-camera motion capture system allowing knee kinetics to be quantified using a musculoskeletal modelling approach. Differences in knee joint kinetics between orthotic conditions were examined using one-way repeated measures ANOVA.The results showed that peak patellofemoral force was significantly increased in the medial (31.81 N/kg) and lateral (31.29 N/kg) wedged orthoses, in comparison to the no-orthotic (29.61 N/kg) condition. In addition, the peak knee adduction moment was significantly increased in the medial (1.10 Nm/kg) orthoses, in comparison to the lateral (0.87 Nm/kg) condition.The results from this study indicate that lateral orthoses may be effective in attenuating runners risk from medial tibiofemoral compartment OA, but that wedged orthoses may enhance their risk from patellofemoral pain.

The influence of hamstrings dynamic stretching on acute performance and distance in young male elite golfers: A Randomized clinical trial

The aim of the current investigation was to examine the effects of orthoses with 5° medial and lateral wedges on knee joint kinetics during the stance phase of running.Repeated measures.Laboratory.Twelve recreational runners.Twelve male participants ran over a force platform at 4.0 m/s in three different conditions (medial orthotic, lateral orthotic and no-orthotic). Lower limb kinematics were collected using an 8-camera motion capture system allowing knee kinetics to be quantified using a musculoskeletal modelling approach. Differences in knee joint kinetics between orthotic conditions were examined using one-way repeated measures ANOVA.The results showed that peak patellofemoral force was significantly increased in the medial (31.81 N/kg) and lateral (31.29 N/kg) wedged orthoses, in comparison to the no-orthotic (29.61 N/kg) condition. In addition, the peak knee adduction moment was significantly increased in the medial (1.10 Nm/kg) orthoses, in comparison to the lateral (0.87 Nm/kg) condition.The results from this study indicate that lateral orthoses may be effective in attenuating runners risk from medial tibiofemoral compartment OA, but that wedged orthoses may enhance their risk from patellofemoral pain.

Influence of cross-fit footwear on patellofemoral kinetics during running activities

The aim of this work was to examine the effects of barefoot, cross-fit, minimalist and conventional footwear on patellofemoral loading during running. Twelve cross-fit athletes ran at 4.0 m/s in each of the four footwear conditions. Lower limb kinematics were collected using an 8 camera motion analysis system and patellofemoral loading was estimated using a mathematical modelling approach. Differences between footwear were examined using one-way repeated measures ANOVA. The results showed the peak patellofemoral force and stress were significantly reduced when running barefoot (force = 3.42 BW & stress = 10.71 MPa) and in minimalist footwear (force = 3.73 BW & stress = 11.64 MPa) compared to conventional (force = 4.12 BW & stress = 12.69 MPa) and cross-fit (force = 3.97 BW & stress = 12.30 MPa) footwear. In addition, the findings also showed that patellofemoral impulse was significantly reduced when running barefoot (0.35 BW·s) and in minimalist footwear (0.36 BW·s) compared to conventional (0.42 BW·s) and cross-fit (0.38 BW·s) footwear. Given the proposed association between patellofemoral loading and patellofemoral disorders, the outcomes from the current investigation suggest that cross-fit athletes who select barefoot and minimalist footwear for their running activities may be at reduced risk from patellofemoral joint pathology in comparison to conventional and cross-fit footwear conditions.

Peak Patellofemoral and ACL/PCL Forces While Performing the Forward Lunge Exercise With Varying Techniques

PURPOSE: To compare peak patellofemoral and ACL/PCL forces among varying lunging techniques involving lunging with a long and short stride both on flat ground and up to a 4 inch platform. METHODS: Sixteen male and female subjects (mean bodyweight 678N, 69.1 kg mass; 175.9 cm height; 28.9 years old) using bodyweight only performed a forward lunge with a long stride (shank vertical at bottom position) and a short stride (1/2 the long stride distance) on flat ground and up to a 4 inch platform. Force platform and video data were collected and input into a biomechanical model, and peak patellofemoral and ACL/PCL were calculated as a function of knee angle. A One-Way Repeated measures ANOVA assessed significant differences among lunging techniques (p<0.05). RESULTS: Peak patellofemoral force occurred between 79°-96° knee angles and was significantly greater (p<0.001) with a short stride lunge on flat ground (1668±479N) and up to a 4 inch platform (1553±580N) compared to lunging with a long stride lunge on flat ground (1193±512N) and up to a 4 inch platform (1061±523N), but no significant differences in peak patellofemoral force were found between the two short stride lunges (p=0.99) and between the two long stride lunges (p=0.99). Peak ACL force occurred between 7°-12° knee angles and was not significantly different (p=0.70) among any of the lunging techniques. Peak PCL force occurred between 62°-83° knee angles and was significantly greater (p<0.001) with a long stride lunge on flat ground (554±220N) and up to a 4 inch platform (609±265N) compared to lunging with a long stride lunge on flat ground (402±114N) and up to a 4 inch platform (458±145N), but no significant differences in peak PCL force were found between the two short stride lunges (p=0.99) and between the two long stride lunges (p=.99). CONCLUSIONS: Lunge technique variations did affect peak patellofemoral and cruciate ligament forces. Compared to a long stride lunge, lunging with a short stride, which caused the knees to translate forward approximately 8 cm beyond the knees at bottom lunge position, resulted in greater peak patellofemoral force but less PCL force. Lunging technique variations did not affect peak ACL force. There were no patellofemoral or PCL differences in peak force between the two long stride lunges or between the two short stride lunges.

The influence of ergometer pedaling direction on peak patellofemoral joint forces

Objective. To compare patellofemoral joint forces during forward pedaling and reverse pedaling on a bicycle ergometer. Design. Experimental within-subject design. Background. Clinicians addressing patellofemoral pain syndrome often strive to achieve quadriceps strength while reducing forces at the patellofemoral joint. Related to this goal, previous research has shown greater activity in the quadriceps during reverse pedaling compared to forward pedaling on a bicycle ergometer, however, patellofemoral joint forces were not examined. Methods. Twenty-one healthy males performed 5-min exercise bouts for forward and reverse pedaling while normal and tangential pedal forces and kinematic data were collected. Inertial properties of each segment were estimated and net joint moments were calculated using Newtonian inverse dynamics. Patellofemoral joint forces ( F pf) were quantified using the equation F pf=2 F Q·sin β/2, where F Q is the quadriceps force and β is the patellar mechanism angle. Results. Reverse pedaling exhibited a 110% greater peak patellofemoral joint force and a 149% greater quadriceps force than forward pedaling. Peak effective moment arm lengths were not different between conditions. Conclusions. Reverse pedaling is associated with a greater peak patellofemoral force than forward pedaling. The peak force was influenced by the quadriceps force and not by the moment arm length. Relevance Insufficient data exist concerning the use of reverse pedaling as an alternative to forward pedaling for rehabilitation of knee disorders. Although quadriceps activity appears greater for reverse pedaling compared to forward pedaling, greater peak patellofemoral forces contradict clinical treatment goals for patellofemoral pain syndrome and may lead to load-elicited pain or damage to joint structures.

THE EFFECTS OF TECHNIQUE VARIATIONS ON KNEE BIOMECHANICS DURING THE SQUAT AND LEG PRESS 887

The current study quantified tibiofemoral compressive force, patellofemoral compressive force, and cruciate ligamentous (ACL/PCL) tensile force during a dynamic barbell parallel squat (SQ) and Body Master (MD-117) leg press (LP) using varying stances (narrow and wide), foot angles (straight and turned out 30°), and foot placements (high and low). Ten experienced weight lifters served as subjects, using their 12 repetition maximum weight. A four camera motion analysis system collected 60 Hz video data from reflective markers positioned over bony landmarks, while two AMTI force platforms were used to collect 960 Hz kinetic data. Resultant knee forces were calculated as functions of knee angle utilizing 3-D rigid link models and inverse dynamics. Mathematical muscle models were developed and optimizations procedures utilized in order to estimate tibiofemoral, cruciate ligamentous, and patellofemoral forces. Foot angle and foot placement variations did not significantly effect knee forces. During the SQ and LP peak tibiofemoral, PCL, and patellofemoral forces were approximately 3300N, 2000N, and 4800N, respectively, and occurred near maximum knee flexion. The wide stance (WS) and narrow stance (NS) SQ generated significantly greater tibiofemoral force than both LP exercises throughout most of the knee flexion and knee extension ranges, with the WS SQ generating significantly greater force than the NS SQ. The SQ generated significantly greater PCL tension than both LP exercises, with few significant differences between stance variations. Patellofemoral forces were significantly greater in the WS SQ compared to the LP during knee flexion, while the NS LP produced significantly greater forces than the SQ and WS LP during knee extension. Peak patellofemoral forces were greatest during the NS LP. The greater tibiofemoral forces generated during the SQ may help protect the knee against excessive shear forces. No ACL tension was generated in the SQ and LP, while the SQ generally generated the greatest PCL tension. The greatest patellofemoral forces generated during the NS LP may predispose the patellofemoral joint to increased risk of chondromalacia or osteoarthritis compared to the SQ or WS LP exercises.