Research Corner - Q&A Knee Extension Research by Lenny Parracino | Date Released : 15 Jan 2000 0 comments Print Close Question: Many of my clients complain that the knee extension machine is not comfortable. What are your thoughts? How would you effectively use this machine? What are your suggestions on quadriceps training? Answer: As with all exercises (movements), you should always have a goal. If you were to state your goal is to isolate the knee extensors (quads), then the knee extension machine fits the goal. However, like many, this machine is considered a non-functional means of load application. The strength gained on this fixed plane apparatus is not useful unless a conscious effort is made to apply the strength through patterns of movement. Research has shown that unidirectional strength training (seated leg extension) of the agonist (quadriceps) can reduce co-contraction of the antagonist (hamstrings). This could be considered a serious situation, as it may compromise joint stability and predispose some population groups to an increased risk of injury. Unidirectional strength training is not advisable for people who require the control of joint stabilization through co-contraction. We are not saying this machine is bad! However, like all exercises, the selection should fit your objective! For example, let's consider that your client’s goal is maximum muscle hypertrophy of the knee extensors. The knee extension machine can be a useful tool. Performed correctly, you can isolate knee extension, thus employ a stimuli to the quadriceps. The key component is in understanding the body, not the machine! In other words, do not conform to the machine - the machine should conform to you! Over the years, I have witnessed many participants sit in the leg extension machine without any attempt to make adjustments for their anatomy. Quite often, a person will sit in an externally rotated position at the hip, causing the knee, which is a functional hinge joint, to experience disproportionate loads. This improper alignment is analogous to hanging on a door as it swings. To perform this isolated exercise as safe as possible, I have provided a knee extension machine guideline along with an alternative way to perform knee extension using a whole body approach. I hope this expands your thought process when considering exercises for your clients as well as yourself. Knee Extension Machine Guidelines The axis of each knee must be aligned with the fixed axis of the machine. The knee caps should point straight up so they appear centered. The foot position is not an indicator of knee alignment The entire leg should be held firmly against the seat to prevent the butt from raising when initially lifting the load. It also prevents a "seesaw" action from being employed to lift more weight. Performing a standing leg extension emphasizes the quadriceps while strengthening the stabilizers (the little muscles that keep the big muscles moving smoothly and efficiently). Improving the strength of the standing leg will help to preserve the hip, knee and ankles. Other benefits include: Improved coordination of legs, trunk and upper body Full body workout = greater caloric expenditure Multiple training angles Improved leg stamina Postural challenge When performing the Standing Cable Knee Extension, follow these guidelines: Stand "tall" with working leg attached to an ankle cable strap. If support is available in front of you, use your hands to balance; otherwise balance free form. Draw your belly button in toward your spine. Straighten the cable-attached leg forward. Maintaining control, return to the start position and repeat movement. Back to top About the author: Lenny Parracino Lenny Parracino is a former author, hands on instructor and clinician for The National Academy of Sports Medicine. Currently, he serves as a faculty member of the Gray Institute of Applied Functional Science. He has spent over 20 years serving the health industry as an international lecturer, soft tissue therapist and movement therapist. Lenny has performed over 300 lectures/workshops, has written educational materials and consulted/lectured in the fitness, manual therapy and educational industry and for various medical organizations around the world. Lenny has earned his degree in Health Science, is a Fellow of Applied Functional Science, holds a California certification/license to practice soft tissue therapy. As a full time clinician, he integrates an eclectic approach of movement conditioning with Dr. Vince Guagliano and Dr. Carina Escudero at AIM Sports Medicine in Hermosa Beach, California. Full Author Details Related content Content from Lenny Parracino Post Knee Replacement Lenny Parracino | Articles Leg Extension/Curl Machines Noah Hittner | Articles Knee Extension Mechanics Noah Hittner | Articles Knee Instability Lenny Parracino | Articles Nerve Damage in Shoulder Lenny Parracino | Articles Disc Bulge Lenny Parracino | Articles Arm Amputation Lenny Parracino | Articles Toe Walking Lenny Parracino | Articles Bicep Injury Lenny Parracino | Articles Plantar Flexion and Walking Lenny Parracino | Articles Narrow Chest Lenny Parracino | Articles Pain, Numbness in Anterior Tib Lenny Parracino | Articles Under Active Glutes and Over Active Erector Spinae Lenny Parracino | Articles Pubic Symphysis/Osteitis Pubis Lenny Parracino | Articles Inguinal Herniation Lenny Parracino | Articles Hamstring Injury Lenny Parracino | Articles Over Pronation and Running Lenny Parracino | Articles Heavy Weights After Shoulder Surgery Lenny Parracino | Articles Calcification of Shoulder Joint Lenny Parracino | Articles Stiffness/Pain in Knee Lenny Parracino | Articles Bilateral Patella Tendonitis Lenny Parracino | Articles Numbness Below Shoulder Blade Lenny Parracino | Articles Overweight, Diabetes and Herniated Disc Lenny Parracino | Articles Ab Roll Up Lenny Parracino | Articles "Snapped" Medial Deltoid Lenny Parracino | Articles Bulging Disc, Numbness in Leg Lenny Parracino | Articles Chin Tuck Lenny Parracino | Articles Tight Hamstrings and Calves Lenny Parracino | Articles Corrective Exercise for Back Injury Lenny Parracino | Articles Impingement During Squats Lenny Parracino | Articles Leaning Forward During Lunge Lenny Parracino | Articles How Many Degrees Should the Feet Point Out? Lenny Parracino | Articles Orthotics - Good or Bad? Lenny Parracino | Articles Reduced Pubic Symphysis Gap Lenny Parracino | Articles Too Much Weight Loss with Running? Lenny Parracino | Articles Arm/Opposite Leg Tightness Lenny Parracino | Articles Post Abdominal Surgery Lenny Parracino | Articles Kinetic Chain Dysfunctions (I-T Band) Lenny Parracino | Articles Standing Quad Stretch Lenny Parracino | Articles Asymmetrical Pec Growth Revisited Lenny Parracino | Articles Sway Back and Pelvic Misalignment Lenny Parracino | Articles Super Slow Training Lenny Parracino | Articles Leg Extension Machine vs. Function? Lenny Parracino | Articles Weight Loss Plateau Lenny Parracino | Articles Tremors with Leg Curls Lenny Parracino | Articles Plantar Fasciitis and Server's Disease Lenny Parracino | Articles Spinal Muscular Atrophy Lenny Parracino | Articles Post C-section and Exercise Lenny Parracino | Articles Training with No Pectoralis Lenny Parracino | Articles Muscle Spasms with MS Clients Lenny Parracino | Articles Developing Quads for Sports Lenny Parracino | Articles Training Variables for Muscle Endurance Lenny Parracino | Articles Patella Injury Lenny Parracino | Articles Arthritis in the Hip Lenny Parracino | Articles SI Joint Trouble & Prolotherapy Lenny Parracino | Articles Lymphedema and Exercise Lenny Parracino | Articles Large Legged Female Athletes Lenny Parracino | Articles Lactic Acid Lenny Parracino | Articles Back Popping with Rotation Lenny Parracino | Articles Back Extension Technique Lenny Parracino | Articles Extreme Rheumatoid Arthritis Lenny Parracino | Articles Shooting Knee Pain with Squats Lenny Parracino | Articles Improving Vertical Leap Lenny Parracino | Articles Asymmetrical Pec Growth Lenny Parracino | Articles Wheelchair Client Lenny Parracino | Articles Whiplash with Racing Sports Lenny Parracino | Articles Out-turned Foot with Running Lenny Parracino | Articles Client with No Legs Lenny Parracino | Articles Core Controversy: To Draw In or Not? Lenny Parracino | Articles Hearing Impaired Client Lenny Parracino | Articles Elderly Prolapsed Uterus Lenny Parracino | Articles Whiplash with Racing Sports Lenny Parracino | Articles Controlled Hypertension & Exercise Lenny Parracino | Articles Disc Herniation Recovery Program Lenny Parracino | Articles Upper Crossed Syndrome in Seniors Lenny Parracino | Articles Pigeon Chest Strength Training Lenny Parracino | Articles Bench Press: Pushing the 1RM Lenny Parracino | Articles Pregnancy Trimesters and Exercise Lenny Parracino | Articles Exercise and Parkinson's Disease Lenny Parracino | Articles Training Rotational Movements Lenny Parracino | Articles Exercise and Parkinson's Disease Lenny Parracino | Articles Post Knee Replacement Lenny Parracino | Articles Eccentric vs. Isometric vs. Concentric Load Lenny Parracino | Articles Muscle Symmetry & Dominance in Youth Lenny Parracino | Articles Power Lifting Fanatic Lenny Parracino | Articles Hypertrophy in Lower Body for Men Lenny Parracino | Articles Client with One Arm Lenny Parracino | Articles Fat Calipers Lenny Parracino | Articles Hip Disparity Lenny Parracino | Articles White Water Kayaking Lenny Parracino | Articles Exercise Hypertension Lenny Parracino | Articles Upping Your 1 Rep Max Lenny Parracino | Articles Formula 1 Race Training Lenny Parracino | Articles Epilepsy and Exercise Lenny Parracino | Articles Lower Back Pain with Ab Work Lenny Parracino | Articles Cellulite on Stomach Lenny Parracino | Articles Kinetic Chain Exercises for Home Lenny Parracino | Articles Strength Training for Weight Loss and Sculpting Lenny Parracino | Articles Step Up Routines Lenny Parracino | Articles Quadricep Exercises Lenny Parracino | Articles Right Grip Lenny Parracino | Articles Fluid Intake Consequences Lenny Parracino | Articles PNF (Proprioceptive Facilitation) Lenny Parracino | Articles Shoulder Tendonitis Lenny Parracino | Articles Incontinence and Exercising Lenny Parracino | Articles Burning Sensation in Feet on Elliptical Machines Lenny Parracino | Articles Osteitis Pubis and Exercise Lenny Parracino | Articles Back Pain and Flexibility Lenny Parracino | Articles T-Bands Swelling Lenny Parracino | Articles A Simple Guide to Stretching Lenny Parracino | Articles Chest Exercises on Bench Lenny Parracino | Articles Strength Lost if Focus on Endurance Lenny Parracino | Articles Lower Trapezius Exercises Lenny Parracino | Articles Degenerative Facet Joints Lenny Parracino | Articles Muscle Balance or Flexibility Profile Lenny Parracino | Articles Hypertrophy and Genetics Lenny Parracino | Articles Postural Profile Lenny Parracino | Articles Overhead Squat: Total Body Profile Lenny Parracino | Articles Hydrotherapy Techniques Lenny Parracino | Articles Winged Scapula Lenny Parracino | Articles Anorexia and Exercise Lenny Parracino | Articles Boxing Performance Lenny Parracino | Articles Bi-lateral Piriformis Release Surgery Lenny Parracino | Articles Muscle Hypertrophy Lenny Parracino | Articles Marfan Syndrome Lenny Parracino | Articles Piriformis Lenny Parracino | Articles Benching Myths Lenny Parracino | Articles Overtraining and Hypertrophy Lenny Parracino | Articles Vegans and Protein Lenny Parracino | Articles Integrated Anatomy for the New Millennium Lenny Parracino | Articles Neck Exercises Lenny Parracino | Articles Upper Crossed Syndrome Lenny Parracino | Articles Fat Loss Plateau Lenny Parracino | Articles Post Viral Fatigue Syndrome Lenny Parracino | Articles Varicose Veins Lenny Parracino | Articles Wheelchair and Cardio Lenny Parracino | Articles Lou Gehrig Disease Lenny Parracino | Articles Hysterectomy Lenny Parracino | Articles Sherwins Disease Lenny Parracino | Articles Lupus Lenny Parracino | Articles Bad Knees and Cardio Lenny Parracino | Articles Weight Belts Lenny Parracino | Articles Knee Pathology Lenny Parracino | Articles Lifting Posture Lenny Parracino | Articles Bruising Lenny Parracino | Articles Chemotherapy and Exercise Lenny Parracino | Articles Kidney Transplant and Exercise Lenny Parracino | Articles Body Fat Loss and Muscle Loss Lenny Parracino | Articles New Shoes and Pain in Calf Lenny Parracino | Articles Back Squat vs Front Squat Lenny Parracino | Articles Multiple Sclerosis and Weight Loss Lenny Parracino | Articles Stretches During Pregnancy Lenny Parracino | Articles Weight Loss: No Results from Exercise Lenny Parracino | Articles Abdominal Wall Strain Lenny Parracino | Articles Multivitamins - Yes or No Lenny Parracino | Articles Breastfeeding and Weight Loss Lenny Parracino | Articles Cervical Disc Rupture Recovery Lenny Parracino | Articles Client Goals Lenny Parracino | Articles High Cholesterol Lenny Parracino | Articles Sciatica Lenny Parracino | Articles Muscle Failure Lenny Parracino | Articles Ephedra Lenny Parracino | Articles Decline in Cardio Fitness and Strength Lenny Parracino | Articles Polycystic Ovarian Syndrome Lenny Parracino | Articles Abdominal Surgery Lenny Parracino | Articles Restaurant Eating Lenny Parracino | Articles Thoracic Tumor Rehab Lenny Parracino | Articles Office Stretch Handout Lenny Parracino | Articles HIV Positive Client Lenny Parracino | Articles Postural Deviations Lenny Parracino | Articles Bicep Rehab Lenny Parracino | Articles Irritable Bowel Syndrome Lenny Parracino | Articles Too Large for Machines Lenny Parracino | Articles Pooch Belly Lenny Parracino | Articles Slow Metabolism Lenny Parracino | Articles Computer Headaches Lenny Parracino | Articles Exercise Guidelines for Pregnancy Lenny Parracino | Articles Deadlifts - The Right Way Lenny Parracino | Articles Preacher Curl Pain Lenny Parracino | Articles Range of Motion Lenny Parracino | Articles Osteoporosis: A Case Study Lenny Parracino | Articles Replacement Drinks for Weight Loss Lenny Parracino | Articles Building Chest Mass - Incline, Decline or Flat Chest Exercises? Lenny Parracino | Articles Knee Extension Research Lenny Parracino | Articles Pregnancy and Weight Gain Lenny Parracino | Articles Functional Carry Over - Applying it to Personal Training Lenny Parracino | Articles Pelvic Tilt Before Crunch Lenny Parracino | Articles Lower Back Pain Lenny Parracino | Articles Biceps Workout Lenny Parracino | Articles Fibromyalgia Lenny Parracino | Articles Please login to leave a comment Comments (0) Back to top