Biomechanics of Running: 4 Ways to Improve Your Form

Edited by: Danielle Abel

Whether you're a seasoned runner or a coach working with athletes, understanding the biomechanics of running can unlock more efficient movement, reduce injury risk, and improve overall performance. In this article, we’re breaking down four fundamental elements of running mechanics—arm swing, torso lean, ground contact, and pronation—to help you or your athletes move with more intention and control.

Arm Swing: It Matters More Than You Think

From a biomechanics standpoint, arm swing plays a critical role in counterbalancing angular momentum generated by the lower limbs. When you run, your arms and legs move in reciprocal patterns—right arm swings back as the left leg drives forward, and vice versa. This cross-body pattern helps to stabilize the trunk and pelvis, especially during the flight phase, when only one leg is in contact with the ground.

Key mechanics:

• Shoulder joint (glenohumeral): slight extension and flexion in rhythm with leg movement

• Elbow joint: maintained in approximately 90° flexion for mechanical efficiency

• Trunk rotation: minimized through controlled, compact arm motion

Overly exaggerated forward arm swing can create rotational torque in the torso, which disrupts vertical and horizontal force vectors, slowing the runner and increasing metabolic cost. A backward-driven elbow maintains an upright chest and helps improve leg turnover rate, which influences stride cadence and ground contact mechanics.

What to do:

• Relax your hands: Pretend you’re holding potato chips and don’t want to crush them, this cue encourages a loose hand grip, which can help reduce upper body tension
• Drive the elbow back: Cueing a backward motion rather than a forward one helps keep your chest tall and reinforces efficient leg turnover

Torso Lean: Get It From the Ankles, Not the Hips

One of the most common errors in running posture is misunderstanding what “leaning forward” actually means. Many runners will lean from the hips only like a hip hinge. However, true torso lean starts at the ankles—not the hips—and requires your entire body to tilt forward in a straight line. Your shoulders, hips, and ankles should stay aligned. At the same time, brace your core from the middle and sides by pulling the lower ribs down slightly and tilting your pelvis under slightly (chin to belt buckle can be a helpful cue) to prevent lumbar extension or “arching” of the lower back.

This alignment supports efficient forward motion, creating a stacked position throughout the kinetic chain while minimizing unnecessary energy leaks from poor posture or muscle compensation.

Build strength for a better torso lean:

• Try the plank leg raise drill. From a standard plank:
• Contract your abs and draw your rib cage down and under
• Squeeze your glutes and raise one leg at a time to hip height
• Perform 3 sets of 30-60 seconds, alternating leg

This drill builds the anterior core and hip strength needed to maintain a tall posture while leaning the torso as one unit—not collapsing at the hips.

Ground Contact: Stack Your Joints for Better Force Transfer

Ground contact mechanics are all about efficiency. Ideally, when your foot hits the ground, your knee should be stacked over your ankle. This alignment leads to a better transfer of force and reduces braking forces that slow you down and increase injury risk.

Many recreational runners overstride—reaching too far forward—causing their knee to trail behind the ankle at initial contact. This increases load on the joints and makes it harder to maintain speed and rhythm. Proficient runners, on average, have between a 6-10 degree shank angle when contacting the ground, whereas less efficient runners have 15 degrees or more. 

• Measure and increase cadence: Count your current steps per minute (SPM). Most runners fall around 155-160 SPM. Increasing your cadence by 5–10 steps per minute can reduce overstriding and help your foot land closer to your center of mass.

  • Use a metronome app or or music streaming app to search for “165 steps per minute running playlist” 

  • Start with short runs or intervals at your new cadence goal

  • Focus on quicker, lighter steps without forcing stride length

Increasing cadence naturally shortens stride length, which encourages a small shank angle upon foot strike and reduces energy loss from inefficient ground contact.

Pronation: Harnessing the Foot’s Natural Spring

Pronation is often misunderstood as a flaw, but it's actually one of the most important energy-saving mechanisms in running. As your foot hits the ground, it flattens slightly (pronation) to absorb shock and store energy. Then, it recoils (supination) to help push you forward. When used properly, this foot motion can reduce the metabolic cost of running by up to 17% per stride.

Runners with very stiff, high arches often struggle with this natural movement and miss out on the efficiency it provides.

• Drills to improve ankle & foot pronation:

  • Barefoot jump rope: A great entry-level drill that's low intensity 

  • Barefoot single-leg hopping: This drill mimics the single-leg stance seen with running - start with jumps in place and work towards different changes in direction

  • Wedge-supported ankle dorsiflexion drills:

    • Place a wedge under the lateral side of your heel and another under the big toe, then perform ankle dorsiflexion (shin-to-toe movement), encouraging proper pronation mechanics

These drills help mobilize the foot and ankle and train your body to utilize the arch effectively as a spring—not just a static structure. 

Small biomechanical adjustments can make a big difference in how you feel and perform during runs. Whether you're training for a race, building aerobic capacity, or helping athletes improve their form, focusing on these four areas can create a solid foundation for faster, more sustainable movement.

Want to learn more about biomechanics to  help make you or your athlete's performance even better?

Check out our Free Hip Mobility Masterclass to learn a biomechanics based approach to improving hip mobility.