Swimming Technique Video Analysis: Using Your Phone to Spot Technical Flaws

Introduction

Without external objective feedback, many swimmers have been repeating the same technical errors for years without realizing it—because we “feel” like we’re doing well, yet have no idea how large the gap is between our actual movements and the ideal ones.

This problem is very common in Taiwan. Many people have been swimming for years but have never seen footage of their own swimming. The water resistance of modern smartphones has improved dramatically, and with the widespread availability of waterproof phone pouches and underwater camera mounts, every swimmer can now perform technical video analysis at a very low cost.

This article will teach you how to effectively set up, film, and analyze your own swimming footage to identify the technical blind spots affecting your performance.

Filming Equipment and Preparation

Equipment Selection

You don’t need expensive camera equipment. Here are options ranging from low-cost to high-cost:

Equipment	Advantages	Disadvantages	Suitability
Phone + waterproof pouch	Low cost, familiar operation	Limited waterproof depth, inconvenient to secure	Basic use
Waterproof phone case + tripod clamp	More stable, allows underwater filming	Requires purchasing accessories	Recommended
GoPro series	Professional waterproofing, wide angle	Higher cost (NT$3,000–8,000)	Serious training
Poolside tablet mount	Stable positioning	Bulky, needs to be carried	Fixed training venue

At public swimming pools in Taiwan, you should inform the staff of your filming purpose in advance, as some pools may have filming regulations that must be followed.

Pre-filming Technical Settings

• Resolution: Choose at least 1080p (Full HD); if your phone has slow-motion capability, select 120fps or 240fps slow-motion mode
• Stability: Use a tripod or poolside mount to avoid shaky handheld footage
• Angles: You need at least two filming angles to comprehensively analyze technique (see next section)

Key Filming Angles

Side View Above Water

Stand at the side of the lane (pool edge) and film with the lens level with the water surface. This angle allows you to analyze:

• Body’s horizontal position (whether the hips are sinking)
• Head rotation angle during breathing
• The arc shape of the arm recovery
• Overall swimming rhythm and body posture

Side View Underwater

Use waterproof equipment and place the lens 20–30 cm below the water surface, filming from the side. This is the most important filming angle and allows you to analyze:

• Entry angle and entry position
• Elbow height during the catch (whether performing high-elbow pull)
• Pull path (whether crossing the midline)
• Kick depth and rhythm

Front View Underwater

Film underwater action from in front of the swimmer (facing the swimmer). This allows you to analyze:

• Whether both sides of the pull are symmetrical
• Body tilt during breathing
• Whether the kick is balanced

Direct Overhead View

Stand at a high point and film downward (or use a mount fixed directly above the lane). This allows you to analyze:

• Whether the hand entry position is on the shoulder-width extension line
• Whether there is a crossing-the-midline entry problem
• Left-right body symmetry

Key Checkpoints for Footage Analysis

Freestyle Technique Checklist

Entry and Catch:

• Fingertips enter first, at approximately a 45-degree angle
• Entry position on the shoulder-width extension line (not crossing the midline)
• Elbow higher than the wrist during the catch
• Forearm gradually becomes vertical to the water surface

Pull and Exit:

• Pull extends through to beside the thigh
• Pinky side exits the water first
• Recovery arc height is moderate

Body Position:

• Body remains horizontal (hips do not sink)
• Body rotation of approximately 15–30 degrees (not over-rotating, nor completely flat)

Breathing:

• Head rotates rather than lifts
• Head returns to the water immediately after breathing

Priority Areas for Slow-Motion Analysis

Slow motion (below 0.5x speed) is particularly suitable for analyzing:

1. The catch moment (elbow height is hard to see at normal speed)
2. Splash at entry (splash size reflects the quality of the entry angle)
3. Head rotation trajectory during breathing (whether it’s rotation or lifting)
4. Flip turn details (wall touch position and depth)

Building a Technique Improvement Cycle

Effective technical video analysis isn’t just “film and take a look”—it’s about building a continuous improvement cycle:

1. Film your current technique (baseline record)
2. Analyze and identify the 1–2 technical issues that most affect efficiency
3. Design a targeted practice plan
4. Execute 2–4 weeks of improvement training
5. Film again and compare the differences before and after improvement
6. Repeat the cycle

Focus on improving only 1–2 technical points each time, avoiding the loss of focus that comes from trying to fix too many issues at once.

Common Analysis Findings

Among swimming enthusiasts in Taiwan, video analysis most frequently reveals the following issues:

• Most common: Sinking hips (approximately 70% of amateur swimmers have this problem)
• Second most common: Entry crossing the midline, causing a snake-like swimming path
• Third most common: Head lifting rather than rotating during breathing
• Fourth most common: Dropping elbow during the catch (low elbow)
• Advanced issue: Pull not finishing through to the thigh, shortening the effective pull distance

Practical Advice

• Don’t over-correct your stroke during the first filming session—swim “naturally” first to see your true everyday swimming state
• Film once every 1–2 months to build a visual record of technical progress
• Share footage with a coach for more professional technical advice, giving both parties a shared objective reference
• Several swimming communities exist in Taiwan (such as Facebook swimmer groups), where sharing footage can earn community feedback
• When analyzing footage, first look at the “overall impression” (whether body position is good), then move to details (such as entry angle)

Conclusion

Swim technique video analysis is an accelerator for self-improvement. It lets you see movements you can’t feel and identify problems you weren’t aware of. With smartphones being so ubiquitous today, no swimmer needs to guess about their technical problems in the dark. Give yourself one filming session—you may be surprised by the technique you “thought was fine”—but that surprise is exactly where technical progress begins.

Related Reading

• Swim Technique Video Analysis: How to Use Underwater Filming to Identify Your Flaws
• Self-Analysis Through Swim Video: Technical Diagnosis Methods for Above- and Underwater Filming
• Swim Video Analysis: Key Observation Points for Above- and Underwater Filming
• Video Training for Swimmers: Practical Applications of Underwater Video Analysis