Nagging knee and back problems can halt your progress and sap your motivation. But you can still train legs by using the right ranges of motion – ones that allow you to load the muscles while avoiding pain.

Here are eight exercises that'll build your legs even when you're working around a cranky knee or a bad back.

1 – Modified Kickstand RDL

Use these for back-friendly deadlifting.

If you want to avoid a bad back, you need to consider torque at the hip. Torque is the result of force (weight) times distance (moment arm length). To reduce torque at the hip, you must either reduce force by lifting a lighter weight or reduce distance from the joint.

If you've ever wondered why your back feels better deadlifting with a trap bar, it's because the design of the bar allows you to keep the load close to your hips.

Kickstand Romanian deadlifts (RDL's) require far less weight and equipment. They also allow you to develop single-leg strength and stability though your hips. They're somewhere in between a single-leg and regular RDL.

That means they get your hips working harder without needing a ton of weight. They're also relatively meathead-friendly since they don't require as much balance as full single-leg exercises.

Kickstand RDLs are often done incorrectly. The kickstand refers to the back foot position, which isn't there to help. It's merely there to provide an extra point of contact with the floor and light support. Placing weight through your back foot during a kickstand deadlift is like bouncing off the floor when you're doing step-ups. Not cool.

Making a conscious effort to place minimal weight through your back foot is a good place to start. Alternatively, you can modify your kickstand positions using either a low split-squat stand or by placing a foam roller on the floor. Hooking your foot over something gives you a point of contact and a little stability, but it's a lot harder to cheat the movement. Try these with a dumbbell or kettlebell.

2 – Eccentric Reverse Nordic Curl

Use these for research-proven quad growth.

This move has been shown to produce a significant increase in the muscle fascicle length, muscle thickness, pennation angle and cross-sectional area in the quads (1). This joint-friendly exercise allows you to train your quads through a much deeper range of knee flexion than usual.

The key is the controlled three-second lowering (eccentric) component, which places a massive emphasis on the quads with time under tension. This will help with both growth and strength. It also promotes durability in both knee tendons.

If you're a beginner, use only bodyweight. Once you're ready to advance, add load by holding a dumbbell on your chest with both hands.

3 – The Good-Thrust

This is a combo of a good morning and a hip thrust. Use it for spine-friendly glute training.

The standard good morning places a lot of shear force through your lumbar region. That doesn't make it a "bad" exercise, just not the best option if you and your back don't get along sometimes. Try the "good-thrust" instead.

Yep, it's part hip thrust and part good morning. If you don't think it looks like a good morning, just flip the exercise vertically and look again.

The long-lever position of the hip thrust makes it harder with light weight and shifts more emphasis toward your hamstrings. Your glutes and lumber extensors get a good workout too. If you want to further emphasize your entire posterior chain you can press your toes down into the edge of the bench.

Compared to a standard good morning, the load is placed more horizontally. The greatest challenge is at the top of the thrust as your hips extend.

During a good morning, the hardest part is when you're bending over fully. There's very little challenge at the top. During a good-thrust the hardest part is when your hips are fully extended. As your hips lower back towards the floor, your hamstrings get a good loaded stretch as well.

When equipment is lacking and your back's giving you some grief, this is a good alternative to good mornings and even back extensions. Add some weight across your hips to make them harder.

4 – Goblet Slant Board Squat with Tempo Manipulation

Use these for a knee-friendly quad pump.

Use a slant board if you have access to one. If not, you can easily mimic the slant board scenario by propping your heels up on a thick textbook, the bottom step of a staircase, or even on a couple of rolled-up towels.

Using more time under tension is what keeps the quads working throughout the duration of each set. Ultimately, this helps promote muscle growth and it'll also give you a pretty good pump.

Use a strict and controlled tempo during each rep with a 5-second lowering (eccentric) component and a 5-second raising (concentric) component. Aim to get the bottom of your thighs as close to your calves as possible for maximum benefit.

5 – Double-Banded Pull-Through

Use these for back-friendly hamstring and booty-building.

If back pain is your problem with most deadlifting variations, then the pull-through will be one of your best alternatives. It can be done with a cable machine or by holding a band as shown in the video. It's a great option for learning how to move your hips correctly while keeping your spine stable.

Having one band between your legs and another around your hips is a surefire way to get heavy enough loading while being comfortable. That is, if you find "comfort" in lighting your backside on fire.

6 – Band-Resisted Reverse "Sled" Walk

Use these for healthy knees and pumped up quads.

Walking backward while pulling or pushing against a weighted sled is a great quad exercise. No sled? Opt for this variation. All you'll need is a heavy band.

Loop that band around your waist and anchor it to a sturdy object. The goal is to mimic the leg action you'd use during a reverse sled drag. The key is to straighten your leg by squeezing your quads during each step.

You'll build your quads while decreasing anterior knee pain. The constant terminal knee extension action brings blood flow to the area, provides for a great leg pump, and promotes patella tendon health.

7 – Dead-Stop Single-Leg RDL

Use these for single-leg strength and hamstring hammering.

This exercise allows you to build functional strength and size without looking like you're in the circus. It's also extremely humbling. A little weight goes a long way.

Find an ideal depth and place something on the floor to limit yourself from going beyond it. A low box, a few plates, or even a bottom step might work.

As you lower into your single-leg deadlift, the step is there to stop you from moving further down the way you normally would with an RDL. The weight in your hand is allowed to partially rest for a two-count while you maintain tension.

The dead stop forces you to overcome the inertia of the dead weight (dumbbell or kettlebell). Inhibiting the stretch-reflex mechanisms will force your muscles to work harder to lift the weight. Isometrically loading your muscles in this stretched position will also create a lot of mechanical tension and muscle damage. You'll know about that the next day!

Since you have an extra point of contact with the floor through the weight, these are also more stable than single-leg RDLs. You'll develop unilateral strength, plus hip and knee stability. Be sure to work within a pain-free and active range of motion for your hamstrings. You can always work closer to the floor over time. If balance is still an issue, place your free hand on a wall to help.

8 – Modified Sissy Squat

Use these for building quads. They may also help you build up to doing full sissy squats.

Time under tension is pivotal here since you'll want to do this exercise in a slow and controlled fashion. Use a stack of Airex pads or an object 6-12 inches high. Stand in front, lower your knees down to the object, then stand back up. If you're feeling really sadistic, you can combine this with a resistance band looped behind your knees, loading you into terminal knee extension.

Sissy squats go against everything you've ever heard about not allowing your knees to go over your toes. That's a fallacy and it's also exactly why this exercise works.

Allowing your knees to go over your toes and into greater flexion is what places stress on the quads and associated knee tendon structures. This stress is what promotes muscle growth. It also promotes tendon durability.

Related:  Try This Knee-Friendly Quad Killer

Related:  Rock-Hard Glutes, Strong Hamstrings

Reference

  1. Alonso-Fernandez D, Fernandez-Rodriguez R, Abalo-Núñez R. Changes in rectus femoris architecture induced by the reverse nordic hamstring exercises. J Sports Med Phys Fitness. 2019 Apr;59(4):640-647. doi: 10.23736/S0022-4707.18.08873-4.